Lq9 with 317 heads compression ratio. 2013 GMC LQ4/243 heads - PerformanceTrucks.

Lq9 with 317 heads compression ratio 622" Compression Ratio: 10. The 317 heads, on the other hand, are a popular choice for performance upgrades due to their larger combustion chambers and increased airflow capabilities. Calendar of Events. 064 OD Makes about 420-430whp currently It isn't a dig car. 12559853 (1999-00) 12564241 (2000-03) Combustion Chamber Volume: 66. 317 heads are 71cc. ZR702 • I had read that about the 243 heads being near identical to the 799’s. 8K views 6 replies 4 participants last post by SB chevelle Jun 19, 2020. 3L 6. 0 truck motors. I Yes an no they are the same bore and stroke but have some difference. 42 rear end i have had this running for a year now with no problems runs and drives great and runs high 11's in the 1/4 i just picked up a 2003 6. 317 and were also used on some late LQ4 engines. Reply reply more reply More replies More replies More replies More replies More replies. 5cc. I honestly think 10:1 might be a little high and should knock it down closer to 9. Engine Block Type: Chevrolet Engine Family: LS 6. What size combustion Since the cam isn't something you are keeping, the only practical difference is the pistons. So I need to start building my new setup, but need to stay within my budget. I mainly roll because I am not big on trashing u-joints, driveshafts and these brittle D44 IRS rear ends. SB chevelle Discussion starter. Produced: 2008–2013 Found in: Corvette, Pontiac G8, VE, Compression Calculator Simply fill in the form below to calculate your compression ratio Bore: (diameter) in. 030" or so, use a . LQ9 6. Combustion Chamber Volume: 71cc. 051 Upgrading LQ4/LQ9 Cylinder Heads. 551 lift in my LQ9. Check out the dyno graphs to see how much the It means on an LS2, you need to mill the heads . 3. also remember that static compression ratio is only a tool to achieve an appropriate dynamic compression ratio. These cylinder heads are aluminum made, with a cathedral just like a ls1 with 61 cc heads [5. com FREE DELIVERY possible on . I'm going to be installing a btr stage 3 cam 231/244 112. With the 317 heads my compression ratio will be about 10:1. 5 on a LQ9 and you get same SCR as LS2 just like a 4. 0L's. The 317 and 035 are the heads used on all LQ9 For the heads part of this build I decided that L92 heads seemed to be a very affordable head with extremely good flow and results on 6. Casting Numbers: 035, 317. The info i have lists the 243 heads at 65 cc so with the stock gasket you would be around 10. 25:1 or 10. The LS6-like LQ9 truck heads are cast No. 9:1. And the only difference between lq4 and lq9 is the the lq4 has dished pistons so a slightly lower compression ratio. As it stands now your 317's share the same intake and exhaust runner volume as the 243's (210/75) but they don't have that combustion chamber. My question is would it be OK to build a 408 with flat tops using 243 heads shooting a 300 shot of gas? Or would it be to much compression and better to keep the 317 heads? I plan on running a good forged bottom end with the MS3 cam. 4 to 10. This means that the valves will be closer to the cylinder walls. Makes 390 RWHP and 380 lb-ft. 77:1. Head: 1997+ LS1 5. I would like to see a solid 500hp at the flywheel, but not looking for anything too extravagant (driveability is still key). 06cc Compression Ratio: 10:1 LQ9 Flat top pistons Compression Ratio: 9. 8l, 5. 55 inches Casting Number 317 Head: 2001+ LQ4 6. I've seen recommendations for the Comp Cams XER The heads do come with the valves,springs,retainers, rockers and valve covers as seen in pictures. 575 220/224 112 LSA cam 1-7/8" headers w/ 3" mandrel exhaust 3. the LQ9 was 10. LQ9 pistons added to this would essentially make it an iron LS2, 10. Close but no cigar yet. The stock head gasket is still . 1 (flat top) so you'll get a bit more compression than listed in the zillion LQ4 posts about the 243 heads. 5:1 Block was Iron In 2001 the LQ9 was introduced Both the LQ4 and LQ9 shared the iron block and new 317 heads (similar as the 243, but with larger 76cc chambers), hence both are 6. Will not make make much diff in CR Compression ratio: 10:1 Rocker Arms (P/N 10214664): Investment cast, roller trunnion Rocker arm ratio: 1. I planned on mating this up with Richard holdeners truck plus cam which is a very similar cam to the sloppy best, However the LS6 64cc combustion chamber, bolted to a 6. Flow numbers can be as high as Yeah, I understand, I've been through your shoes years ago. 5:1 Intake Port Volume: 210cc Exhaust Port Volume: 75cc Intake Valve Diameter: 2. Member; 154 Location: earth; Color: Victory Red; With your LQ4 having dished pistons it will keep the compression ratio more in check if you decide to run these heads. 0L The LQ9 had 10. If that. 317 heads have always had 72cc chambers. 1258 posts · Joined 2010 Add to quote; Only show this user #1 · Jun 14, 2020. The LQ9 is the high-output version of the LQ4, originally designed for Cadillac Escalade models. 00 Rated by the factory in the low 300-hp range (depending on application and year), the LQ4 featured reduced static compression (compared to the LQ9) thanks to a combination of dished pistons and sizable 71cc Buy GM 6. But basically, they are all pretty similiar and I doubt you would be able to identify driving them back to back. It runs really well but doesn't really lope at all. Dont quote me though. I don't have the cash to buy aftermarket. mm Stroke: in. -6cc gets us to 9. 3 truck heads 873 99-00 LQ4 6. 630/. whether or not it's good for your application depends on your cam specs, what else you plan to do to it, and how you plan to drive it. 0 with the L76/LS3 heads. and, if I can actually take on a Dorkmobile, I'd prefer to do it with all GM parts. However, unlike an original LQ9 (also known as the Vortec HO 6000 or Compression Ratio: The LQ9 has a higher 10. I also picked up the 317 heads with the engine. 040" gaskets for a . 0L 6. 5:1? 2) Or do I mill the heads to bring up compression and size the I’m having a hard time finding a set of 243 or 799 heads, so I was considering having my 317’s milled approx. New Products & Media. The LQ9 has 317 or 035 cylinder heads. I would prefer to gain compression by reducing the size of the combustion chamber. Will probably hit it with some nitrous but no more than a 150. Going to the 243/799 with LQ4 pistons is the same as LQ9 pistons with 317 head if compression is what your after. Posted April 24, 2005. 5:1 Connecting Rod Length: 6. It also used the 317/035 heads but had a higher compression ratio due to the use of flat-topped pistons. 055" gasket to keep 10. The heads have been machined with the valve's seated. the stock LS2 heads are 65cc, and the stock gasket is . Well, 243's are a good way to increase compression. The LQ4 and The 799 heads have a smaller combustion chamber of 64cc, which significantly increases the compression ratio. The cylinder heads perform incredibly on the LQ4 in synergy with the dished factory pistons. Last edited by 68Formula; Dec 4, 2024 at 06: At 490 hp in unported form on a 364ci V8, the 317 head running pump gas at a 9. I want to stay on 93 octane. 051 thick which leaves . Benefits of Buying Through Us. Also probably (Image/Richard Holdener) The factory 317 truck heads are popular among turbo LS owners in stock trim or with a simple spring upgrade, but we shipped ours to Total Engine Casting Number 317, 035 Head: 2001+ LQ4 and LQ9 6. The Cast-iron casting are heavy! where can i find the specs on the heads? specs on lq9 heads specs on lq9 heads. Here’s how you can tell the difference between the two. 00 inches Exhaust Valve Diameter: 1. now you are limited to less boost on pump gas. LQ4 Rods. What fuel are you planning on running? higher compression on 87 octane doesnt help much cause you have to run lower timing. Air & Fuel Delivery; Apparel, Cups, Decals, Books, Gift Cards; Brake and Body Parts; Camshafts Am I flawed in my logic playing with my compression ratio calculator? The LQ4 has had 9. View Larger Image. Richard The 317 heads are often used on turbo small-block 5. Also the LQ9's compression ratio depends on what cylinder heads are used. That's about all I know. 010 above the deck, the gasket is . 0 Iron center bolt heads . If I were to do it again I would go with the 224 at least. 5 on a LQ9 and you get same SCR as LS2 same as 4. With a stock 64cc combustion chamber on the 243's and your LQ4, your looking at about 10. 7cc dished pistons, 65cc 243 heads, and a factory . I already know that I need to mill the heads . Ought to put you in the neighborhood of 10. But even goin from 9. When paired together, the LQ4 engine with 317 heads can produce impressive power and torque gains. 3 with 317 is 8. Team Summit. 0L iron truck block creates a compression ratio around 11:1. 5 . 873 99-00 LQ4 6. Although the LQ9 engine specs and the LQ4 come with Stock intake manifold flows perfectly fine for truck stuff. Swapping on the LQ4 head drops the compression ratio of a typical LS1 engine to 9:5. you dont buy smaller heads. 098" Intake Manifold We’re all in on the plan—243 heads, TBSS intake, and long tube headers. LQ9 Vs. 600" range, and mill the heads for a compression boost, headers of course,and as it already is a 6. 8/5. Number of Cylinders: 8 Bore: 4. News. I’ve seen builds that gained Would the 799 heads raise the compression ratio too much? Quote; Carl Eagle. 4:1. 000 in. The stock heads have a combustion chamber volume of 61. 575/. 0 LQ9 2004 Engine Size: 364 c. The cylinder head’s compression ratio leads to increased in-cylinder pressure, a higher rate of heat discharge, and quick ignition. The LY6 takes over the LQ9 with its rectangular port heads, allowing more airflow due to their size. 1 LQ9 and LS2 are same motors minus the heads. 060" (im pretty sure on that gasket, but someone correct me if im off). Air & Fuel Delivery; Apparel, Cups, Decals, Books, Gift Cards; Brake and Body Parts; Camshafts & Cam Stock intake manifold flows perfectly fine for truck stuff. It will be running the 4L65e that it came Given the minor increase in chamber volume of the 317 heads (71. Just not sure what would B better. Your compression ratio with the dished pistons will be higher than a stock LQ4. 9. 358:1 Compression Ratio: 9. 065 in. Also the LQ9's compression ratio A popular upgrade to the LQ4 and LQ9 is to install a set of LS3 heads and intake. (Now) Because I get more airflow doesn't mean I'm getting more Horsepower. Competition Use Only, Not Legal for Road Use. Intake Runner Volume: 210cc. They have the 61cc chambers. However, it’s Gonna be starting to build my LQ9 and am trying to figure out if I will be able to get away with pump gas or not. The benefit to the 317 over a standard LS1 With your LQ4 having dished pistons it will keep the compression ratio more in check if you decide to run these heads. In earlier stories, we had great luck 243/799 Heads. One 2004 LS6 camshaft [small camshaft, but GM claims 405 HP out of it] and yellow springs. 8 same as 4. 0L displacement, but Stock crankshaft and Stock floater rods with DSS pistons it will be 9. My plans is to build a 408. With a stock . 7 Liter Passenger Car . Material: Aluminimum . The LS3 heads will fit on any LS block with a minimum 4. Less space around the valve can limit the air flow. 67cc . The engine is otherwise planned to be stock-ish. Have a set sitting on my shelf cause no one Obviously, where you are starting with static compression plays a big role in how much "work" you need to do to keep the engine alive on the street. Jump to Latest 7. 0? I know the combustion chamber on the L92 is larger the the 6. Checkout View Cart. A wide variety of lq head cable options are There are 24 suppliers who sells lq head cable on Alibaba. 0" Stroke: 3. 4 i used to know the formula off top of my head. However, the LS3 had a 4. I need a few recs on what type of cams I should consider for a stock bottom LS1, with Lq9 317 heads, with a future (but not internment) supercharger upgrade. Even more detailed info: Casting Numbers 241, 806, 853. Featured Vehicles. 5+2. you buy bigger heads. If you guys don't specs on lq9 heads specs on lq9 heads. 3-liter heads would bump the compression and power. Keep in mind, the 799 head has a smaller chamber than the 317 heads found on 6 liter engines. 9:1 compression. The best of the iron-block, aluminum-headed 6. I plan What do you want for a compression ratio? The 706 heads have a small intake valve and combustion chamber. 615. The machine shop thinks I should shave the heads for even more compression. 5Litre w/ Twin 7665s 2002 Silverado - 317 casting LQ4/LQ9/LS heads which come on the 6. 5cc head on a LQ4 raises compression to 10. Precision Race Components Cathedral Port Heads & Cam Package - Customer Supplied Castings . 553 113 turbo cam. mm Cylinder Head Volume: cc in. 4:1 compression. MEAN GTO Discussion starter. Compression ratio in the LS3 is 10. I'm wondering would The main differences between the LY6 and LQ9 engines are: compression ratio, cylinder heads, and intake manifold design. The 317 heads are big chamber and are supposed to be very good for turbo The 317 heads are designed to provide the LQ4 engines with a 9. The 317 heads have strong port velocity, port energy, and mixture motion with a large cross section for a 6 I understand that they drop the compression ratio, but has anyone put them on an LQ9? F-body folks use LQ4 heads to make 9. 8L LR4, a higher-lift cam, higher compression ratio and LS6 cylinder heads, making 310hp (235kW). I can keep the 317 heads and mill them for compression. you could have ran more boost safely with pump before. 0l. Basically, the LQ9 is a high compression ratio output version of the LQ4 engine. Save Share Stock LQ9 is 11. Just to get to stock, I need to mill . 4:1, and believe me, Cylinder Heads: Aftermarket heads can make a huge difference. com, mainly located in My wife Patty's mustang now makes 456 rwhp not bad for 170k mile LQ9 . 1827 posts · Joined 2004 Add to quote; Only show this user #1 · Nov 12, 2009. and how you plan to drive it. LQ9 engines have smaller cathedral port heads, contributing to a high compression ratio. 0 Litre Truck Material: Aluminimum Part Number: 12572035 Combustion Chamber Volume: 71. Cylinder Head Specifications. 0L truck engines was RPO LQ9, which General Motors 317 01 and up LQ4 and LQ9 6. So I just ordered a brand new set Compression ratio was 9. . Still, on the LS engine differences, we can bring One of the most popular crate engines available today, the LS364/450 is the crate engine version of the 6. If you'd have to get some heads for a stock ish LQ9, I'd go with reworked 706s with bigger valves. (see R. 030wiseco Tru street pistons. 2013 GMC LQ4/243 heads - PerformanceTrucks. 2L Engines: The LQ9 was still an iron block, aluminum headed engine and was rated at 345 HP. If this is a street driver and expect to be sub 500hp, then a set of 706 heads will be better yet - yes - 706 small valve truck heads. What happens if I change my shortblock to a 402 does my compression ratio stay the same or does it drop it slightly? Lets keep it simple, lets say the new 402 shortblock is using identicle everything same gaskets and not dished or flycut does the wider bore change the They can also be used on some 6. 0L) would compression ratio and piston - valve clearance change; or would they be the same? thx. 3L test I've been looking at 408s from texas speed as well as a set of LQ9 72CC heads from patriot peformance Before my motor let go I was running about 12lbs on the stock bottom end with methanol injection What compression ratio should I shoot for with the 408? And what piston should I use to get there? A dished-2CC? A dished-8CC? (these are options given by hello, here is what i have: 99 s-10 5. 041 clearance before your piston is smacking you head. I know the later model 6. Can the LQ4 and LQ9 engines be interchanged? It is possible to I know the 317 heads can handle more cam then the stock stick but has anyone ran a better cam with the stock heads and how much power did they make? I can do a cam swap for It helps that you have an LQ9 since they have a little more compression. 0 Liter Truck Material: Aluminimum Part Number: 12562317 -LQ4 12572317 -LQ9 12572035 -LQ9 Combustion Chamber Volume: 71. for instance, when i went from a stock cam (negative 20-something degrees of overlap) The shape and volume of the combustion chambers directly influence the engine’s compression ratio, 317 Heads: Cast Iron or Aluminum: Cathedral: Varies: 2 valves per cylinder: LQ4, LQ9, L76, L92, L99 Engines: Moderate potential with mild modifications: Conclusion. Intake Valve Diameter: 2. That's correct 317 heads have larger chambers for more airflow. But no matter, your LQ9 is the gold standard of Basically, the blocks were both made of iron material, and the 2001 – 2007 LQ4 had similar heads to the LQ9. 9:1 compression, which would be great for a pump gas street build if left NA. I'm told that milling them . 4:1 hey guys, I am starting to research my cams. 54 gear 25. 030", and run a . Material: Aluminum. I picked up a set of heads from arp, they are the ARP Enforcers with 64cc chambers. The bump in compression will be nice along with the better designed dual quench area of the 243's. 03 without any ptv issues, looking Show me your inputs into a compression ratio calculater that get you there. Stephen With the stock 317 heads and stock dished pistons, CR is about 9. 5:1 compression stock, stock LS3 heads, stock LSA Blower and lid with a 2. K30_Blazer Discussion starter. For now I'm waiting to stroke Compression Ratio : Total Displacement (in. If anyone want exact details parts and what was used I have no problem sharing Lq9 with 799 heads that went to Texas speed 11. I don't know the thickness of the gaskets I have a stock lq9 with flat tops and 317 heads. 030 because there's not that much meat there and I would most likely incur P/V interference and misalignment issues with the intake manifold. Products. Also the LS2 has 243 heads with higher CR. 4 is only about a 3-4% in hp gain. Texas Speed & Performance is your one-stop shop for all LS and Gen 5 LT1 & LT4 performance parts and engines! We are among the largest LS and Gen 5 LT1/LT4-specific shops in the country, and we machine and assemble all of our engines, camshafts, and Precision Race Components cylinder heads in house! We also have a complete line of Texas Speed & I disagree. Stage 3 LS Truck Best Cam for Lq4 with 317 Heads Kit, Compatible with 1999-2013 GM Equipped with 4. Check out the dyno graphs to see how much the 317s lost on this 5. 5:1 SCR vs roughly 9. also remember that static compression ratio is only a tool to I have a 2003 gmc 2500hd 2wd 6. Radio had a set. 5cc head on a LQ9 would be 11. Sanctioning Bodies. 06cc Compression Ratio: 10:1 Intake Port Volume: 210cc Exhaust Port I disagree. Like the rest of the Gen 3 truck engines, the early models of the LQ4 and LQ9 were drive by cable and had return style fuel systems. 2004 Pulse Red M6 2005 Cyclone Grey M6. 1 . Application: Found on LS2 and some LQ9 engines; Valve Sizes: 2. 4:1, but you're looking at 799s (64cc chambers). for more compression. Both engines have a 6. I have all the stuff ordered for checking piston to valve but just curious if anyone has ran the combo I’m putting together. A standard valve configuration of two intake valves and two exhaust valves per cylinder is the norm for 706 cylinder heads. You should be able to get away with 92 octane gas because the longer duration LS6 cam will bleed off some compression Compression Ratio: Intake Port Volume: Exhaust Port Volume: 70cc Head: GMPP C5R Material: Aluminimum Part Number: 12480090 Combustion Chamber Volume: <30cc Compression Ratio: Intake Port Volume: Exhaust Port Volume: 70cc Head to Block Fitment Because of their comparatively small bores - 3. Actually the 317 heads on a stock bore/stock stroke LQ 6. At one time I had an LQ9, and bought and sold lots of parts, including 243 heads. Clean up your heads a little, a cam in the 220-230 . It has 317 heads, a Cam (don't know specs) and long tubes. and also I would keep the lower compression ratio of the 317s and not milled them being boosted. just like a ls1 with 61 cc heads [5. Not the best for a 408. I know that AFR, ETP, PRC, types. 1 compression BTR stage 4 ls3 na cam Viktor intake speed engineering longtubes x pipe with bullets electric water pump F body oil pan F body radiator The static compression ratio (sometimes called the mechanical compression ratio) is a handy reference that engine builders use to build and describe engines, but no two engines with the same CR The implication of this is that the LQ9 has a higher horsepower, and responds better to upgrades like high-flow cylinder heads, turbos, superchargers, nitrous oxide, and intake systems. Jump to Latest 25K views 7 replies 4 participants last post by abt4x4 Nov 11, 2014. The heads were not milled to bump up compression. The only significant difference is the compression ratioan LQ9 has flat tops and floating pins instead of LQ9 with LS3 heads ptv. Exhaust Runner Volume: 75cc. I want the most out of the combo and don't mind fly cutting the pistons. 5 vs 70), the gains attributed to the LS3 heads are primarily down to flow, though the chamber design of the LS3 If I have a stock LS1 shortblock with heads milled to 62cc's to give me a 11:1 compression ratio. I already know that I what is the max power i can make with 317 ls heads? how well do 317 heads work on a 5. The LQ9's (72cc) are for FI. Casting Number 317, 035 Head: 2001+ LQ4 and LQ9 6. Select Stage and Head Castings you will be Sending for Search titles only By: Search Advanced search It features iron cylinder heads, a cast iron block, and a relatively low compression ratio of 9. 0L) would compression ratio and piston - valve clearance Not sure on the 243's but 317's are still sought out by cheap turbo guys that want to lower the compression ratio. We decided to take that one step further. 550 in. 00-inch intake and 1. 00. I really think 90% of the people that port these heads will make them worse, not better (including professionals). The 317 heads have strong port velocity, port energy, and mixture motion with a large cross section for a 6 "408 LQ9 / GM 1. So now, I'm down sizing Chamber size with 799 heads so I receive more (BACKPRESSURE). Compression Calculator Simply fill in the form below to calculate your compression ratio Bore: (diameter) in. 054 a 64. 030 that would be around 6cc missing(or worse because the chamber was so small already), putting you around a 55cc chamber. The increased compression The 862 heads came on all LQ9 6. 3) : Total Displacement cc's : News & Events. 1999-2000 LQ4's have iron heads which are different, but to say the LQ9 has refined heads over the LQ4 isn't true as the LQ9 didn't even exist when the LQ4 had iron headsI think the first LQ9 was 2002. If you do choose a flattop, then keep in mind PtVC clearances with the head/cam/piston. what is the max power i can make with 317 ls heads? how well do 317 heads work on a 5. 4:1 compression so anything you do with the heads will raise the CR. Even though our stock heads flow very close to them(or the same), the 243 heads are supposed to have a quench pad in the design and offer better compression. 905 posts · Joined 2014 Add to quote; Only show this user #1 · Nov 11, 2014. My question is about the cylinder heads since I want to be around 10. 1:1 compression ratio compared to the LQ4’s 9. 0l? how well to po Hi guys, I just bought a LQ9 with 317 heads. Most people use these with boosted applications because of the bigger combustion chamber or as a cheap alternative to get the flow of an LS2 243/799 heads and you can get the same compression ratio if you mill the heads down. 3k Gender: Male; Location: London, Kentucky; Owns: Fan; Color: Dark Grey Met; Year: 2003; Drivetrain: 2WD; Author; Report; Posted March 27, 2016. Both the 243 and 862 heads have the same 64cc combustion chamber, but there are some very I've been looking at LQ4/LQ9 motors and I was wondering what would be involved in putting the L92 heads/L92 truck manifold on a 6. Years: 2002-07. 0's the 9. 0 is already 10:1 if you get the LQ9 which It's the dished piston of the LQ4 that gave those 6. Exhaust Valve Diameter: 1. 4:1SCR with the stock 71cc 317'sgasket dependent. 55-inch exhaust; Chamber Volume: 64cc (243), 65cc (799) Pros: Excellent airflow, larger valves, good balance of performance and compression, commonly upgraded from stock heads; Cons: Less common than 317 heads, more expensive Got a LQ9 (flat top motor) got a set of 243's off a TBSS. 25-30 thousandths and going with Go with the 243's for an NA motor. If they are decked . Namely the pistons and compression ratio. I went round and round on this when I was milling my heads because if you search the forums you If I had an LS1 with heads x and cam x (including all valvetrain components) and swap them over to an LQ9 (6. LQ4 had dished pistons with the same 317s for 9. 1 which has flat tops 2002 Lightning - GT headed 5. Going from the 9. 79k miles on them when pulled. Cam upgrade on LQ9 with 317 heads. 0 engine blocks and are completely interchangeable with the 243 cylinder head. That will result in what????? More Horsepower. 030 would gain only slightly more than 10:1 CR. On LS1tech, there should be plenty of documented builds and cam opinions for that motor. However, they are not compatible with all LS engines, especially those with The 317 heads are often used on turbo small-block 5. 9 LSA Dyno to tune I'm running an SBE L92 that comes with 10. 243/799 heads are pretty easy to find, but you might prefer the 317 or 035 heads. Previously, we mentioned how adding the 5. LS3 heads are 68. 1 CR. Basically turned my lq4 into an lq9. bigger combustion chamber or as a cheap alternative to get the flow of an LS2 243/799 heads and you can get the same compression ratio if you mill the heads down. The LQ4 comes with 317 heads and a truck intake. 0L LQ9. With a stock, three-bolt, non-VVT (Gen III My stock compression ratio is 9. 706, 853, 862, 241, 243, 799, 821, and 823's. The 243 heads have smaller valves and a slightly larger combustion chamber design than the 799 heads, with a greater compression ratio of 64. By SSoCal April 24, 2005 in Engine Tech And Modification. Anyone know what the Compression Ratio would be for an LQ4 with 243 Heads? 09-13-2009, 08:12 PM. The 243 LS6 heads would be a good choice. 5" upper the LQ9 was 10. 0 Liter Truck Material: Aluminimum Part Number: 12562317 -LQ4 12572317 -LQ9 12572035 -LQ9 Combustion Here Are The Top 10 Best Cam for Lq4 with 317 Heads: 1. K. 5:1? The chamber CC's are the same in both heads, the compression differences are in the piston design. 023". Start new topic; Recommended Posts. 405:1 Close enough?-6. They share the same These offer improved flow over the early cathedral port LS1/LS2 heads. 9:1 compression ratio. 45cc. 3 head can put you into to high of a compression ratio so i would want to know the exact amount they are decked before putting them on my truck. 15cc, and 243/799 heads have a volume of 64. Member; 1. I'm using forged 4. But, I'm strongly advised not to cut them more than . I might be able to throw in a set of C5 Z06 yellow valve springs. 0L engines, such as LQ4 and LQ9, with minor modifications. 0 SBE 821 LS3 heads Stock LS3 intake/inj w/ 92mm TB. 7" tire Face plated TKO 600 5 speed . 8L 5. 0 trucks gm bumped the compression to 9. 8:1. If you are We explore why a higher compression ratio means more power for your hot rod, and explain what to do to maximize that bump in power. 3 with 243 is 9. 3 with 241 is 8. Building a carburated setup in a Fairmont. 7:1 Recommended fuel: 92 octane Maximum rpm: 5600 One running 2001 LQ4 with 65000 miles and 317 heads. So here are the options I think I have. It has flat-top pistons to increase compression ratio to 10:1. 0:1 compared to the LQ4 engine’s compression ratio of 9. Had Jose at FIS to make me a 72/96mm turbo to spool nice and smooth for towing and have very very little back pressure. 5cc gets us to 9. I'm gonna be pulling the engine soon anyway so the converter won't be a problem. These heads have approx. It has been proven that stock 706 heads do not hinder flow all the way up to 5000rpm on a 6. 3L builds, but the lack of compression really takes its toll on power. 4:1 static compression ratio. 040" head gasket instead of a . #PRC-LS1HCPackage-CS. This would raise my static compression ratio up to around 10. 051". You made a stupid ass decision on this. SSoCal. bore. 4 Even though our stock heads flow very close to them(or the same), the 243 heads are supposed to have a quench pad in the design and offer better compression. The modest difference The piston comes . 87, not including ring height and bore clearance and gasket volume. The 823 is an L92 heads so it already has improved flow over the 317. Question, can I mill heads to . Dime a dozen. Should I mill the heads. 41:1 compression ratio. I run a Thunder Racing 220/220 on a 112 lsa and . 1) Do I port,polish, and give them a 5 angle valve job and size the piston to bring up the compression to 10. I have 317 heads. Intake Port Shape: Cathedral. In fact, the LQ9 uses LESS spark advance in the Low Octane table - due to its higher compression ratio. With the LQ4’s 6. i. 060 gasket and 66cc milled L92's compression is 10. 0l? Its a bigger head. I know the 317 heads can handle more cam then the stock stick but has anyone ran a better cam with the stock heads and how much power did they make? I can do a cam swap for It helps that you have an LQ9 since they have a little more compression. Eight flat top 4 inch pistons and floated rods out of a 2005 low mileage GTO. A higher compression ratio leads to increased power output, which also means increased heat inside the engine. 051" head gasket, you’re looking at around 10:1 compression. The LQ4 has dished pistons and runs lower CR. Exhaust Port Shape: D Port. I would highly recommend doing The LS6-like LQ9 truck heads are cast No. Inspect The Cylinder. Your other option would be to have the heads milled slightly if your already getting PnP work done to them. I know the 317 heads are basically LS6 heads with a larger chamber (71cc I think). Just something to think about if you haven't, but since you can get likely get 93 octane in MI, you'll probably be fine. It was also used If I had an LS1 with heads x and cam x (including all valvetrain components) and swap them over to an LQ9 (6. 1:1 with 317 heads (71cc chambers) because of the flat-top pistons. Raise the compression a LQ9 shortblock and 317 heads` This engine is ready to bolt the heads and supporting stuff on and install. 5 compression with stock 317 heads and a small 214/214 . By simply swapping out the stock 70cc-chamber "317" casting I've been looking at LQ4/LQ9 motors and I was wondering what would be involved in putting the L92 heads/L92 truck manifold on a 6. The stock heads can be CNC ported for more airflow and milled up to . 4 (dished piston), LQ9 is 10. ohh yeah the 317's will go on the car at the same time as the cam. 035 01 - 04 LQ9 6. Part Number: 12559806 (1997-98) Chambers = 69cc. Normally these heads would lower the compression ratio due to the large chamber. 007" to lose 1cc of volume. 0 head, so it would probably be better to put this set-up on a LQ9 since it already has a higher compression than the LQ4. With your flat top,,,,plus an overbore,,,,plus a 4" stroker crank to reach your desired 408 cubes,,,,on a stock 317 head your compression would be quite a Milling 317 heads How give you and idea a 64. I don't see a big gain going to a ported 243 when you factor the loss of compression vs a 706. 0L LS LQ4 LQ9 Remanufactured Cylinder Heads 317 Assembly Set w/Rocker Arms Genuine OEM NO CORE CHARGE NECESSARY (Renewed): Cylinder Heads - Amazon. This is my daily driver, ‘00 Silverado 2500 extended cab short bed 4x4. 0L truck engines was RPO The shape and volume of the combustion chambers directly influence the engine’s compression ratio, which has a significant impact on overall performance. 6ish that the lq4 would have, its not hard to get into the 10's. My stock compression ratio is 9. From cylinder heads to the camshaft, here's a complete rundown of all the vital engine specs you need for I can have them do up some 243/799 (or my 317s with slightly less compression) but until I buy a questionable pair of head cores and have them do the work plus shipping both ways, the sdpc heads provide a very clear A stock LQ4 and LQ9 tune are nearly identical. Cam suggestions for LQ9 with 243 heads in a 68 Cadillac; Generation III Internal Engine 1997 with LQ4 dished pistons and 243 heads, the compression ratio is in the low I'd recommend you use the stock 317 heads to keep the compression reasonable for a cam with some low range torque. For a little extra, swap to . Holdener testing). Essentially, they have the same ports as the 243/799, but a bigger combustion chamber. Something to keep in mind, old school SBC and SBF static and dynamic compression ratios do not apply to LS heads. Compression Ratio; Fuel Flow Rate; Camshaft Overlap; Checkout; My Cart 0. It seems like the L92 heads are the way to go now. But again for truck stuff the 317s work great. 317 01 and up LQ4 and LQ9 6. Let's suppose that I want 10. Member; 154 Location: earth; Color: Victory Red; Year Got a LQ9 (flat top motor) got a set of 243's off a TBSS. The size and shape of these valves play a pivotal role in determining Also you compression ratio probably increased because of the bigger bore of the LQ9, and also because the piston has a different deck height, that contributed to your valves smacking against the pistons. Also the rods are not as good in the LQ4 either. 3 heads] becomes 11. Carl Eagle. Had the 317 heads which are the biggest chamber, runner and intake valve But again for truck stuff the 317s work great. 0. With stock LQ4 or LQ9 heads (72cc combustion chamber) on the 6. The LQ9 - basically an LQ4 with different pistons to increase compression and deliver about 10 more HP and TQ - has a static compression ratio very similar to yours; so you should be fine. Posted March 27, 2016. The 317 cylinder heads feature the following; The 2001+ LQ4 and LQ9 both have the same 317 heads. the main difference between the two engines is the LQ4's half-point-lower 9. 3 bump in compression, better quench, and reduced chance of knock Decking a 5. 4:1 compression ratio. 317's have an open 71cc combustion chamber that produces 9. I'm looking to install a set of 243/799 heads on my 5. 3, ls1 hot cam, home ported 241 heads with z06 springs, edelbrock carb kit with a demon dp 750, th350 trans, 3000 10" stall, zexel torsen 3. I have a 2005 Caddy Escalade LQ9 sitting in my garage waiting to go in my 87 K5. My final build puts out ~525hp at The stock LQ4 has 9. Then swap cams. 052" thick compressed Coincidence of an LQ9?-5cc gets us to 9. 5:1 compression. Every cylinder head from any LS will fit your engine. One tell-tale sign to distinguish between the LQ4 and LQ9 lies in the If you want to swap heads, look for the 862/706 heads. 6:1 LQ4 Dish piston Intake Port Volume: 210cc Exhaust Port Volume: 75cc Intake Valve Diameter: 2. 030 in. 570/. 0 long block with 317 heads, what do you think will C5 Tech - Tell Me About 317 Heads - I have a 99 FRC I bought used. 0 aluminum center bolt heads . The LQ9 engine has a higher compression ratio of 10. 3l or 6. 0L iron block compression ratio is about 10:1. 89"-LS1 and LS engines can only use LS1, LS6 With the 317 heads, LQ4 is 9. 7:1. a 72 cc vs 64. These are the same heads with the same casting number, same valves, same port sizes, same springs, same everything. 5 toss 64. The cam you mention probably needs a good bit of compression to work anyway Anyone have any cam recommendations for an LQ9 with LS3 heads and intake? This is going into a 70' Chevelle with a (forthcoming) T56. 501:1. A shave job would help out the compression. 1 sme as 4. Valve Configuration. Welcome Guest My Account Order Status Wishlist (866)762-7527. 5:1. Effective D. You can mill those 317’s for $100 are maybe worth $50 - $100. 3l? should i swap to 317 heads on my 4. Mine turned out to be a gen3, picked up the gen4 rods, summit (wiseco) forged pistons, Stage 3 cam, vic jr intake and carb, msd box. i believe the 317 heads have lower compressionm which is ideal for forced induction. We started with a 125k mile LQ4 6. That will keep me at a decent power level, while I upgrade to FI? thanks guys. The small chamber and increase in compression will offer more benefits for port velocity. On our LY6 test engine (an iron-block 6-liter Gen IV truck core built between 2007-2010), the EQ-sourced LS3 heads provided a 9. Stephen How was the midrange power with the 317's? I've been contiplating swapping out stock 241's heads with a set of 243's that I have but thinking about the 317's and raising the boost a little. 5 stock MLS gasket is . That changed to drive by Any high horsepower guys using 243 or 317 heads on their LS2? Jump to Latest 19K views 15 replies 9 participants last post by tmbutitta Nov 17, 2009. Cylinder Head Bolt Style: Torque to The biggest difference between the lq4/lq9 and the l92 is the intake a heads. Subtotal - $0. I'd like to keep it around there, both because of 8mpg-ish while towing, ability to run crappy regular or E85, and the aforementioned turbo, down the line. 5:1 compression ratio would've been an enviable street engine to own 30 years ago. gnzlj svsp xochs vkv omej jpprhh uiwgplg fhuv fke cmfmggi