skeeter99

iTrader: (16)

I need a lil advice on which route to take with my cam and the 317 heads. Im getting the T rex cam and i know this cam has tight ptv clearence. Im wanting to know if i will be ok milling the 317 heads to get 10.1 cr or if im better off just leving the heads alone. Im not sure how tight the ptv is with dished pistons in the lq4. Im not really wanting to spend money on 243 heads which i kno would be the best route. I have decided to go the 6.0 route because my friend has a motor for cheap i was going to rebuild my 5.7 but i will be off cheaper the 6.0 way im also trying to decide is the extra motor weight worth the money im saving. Thanks

70Novaproject

After some research, I determined milling is a headache when you get into it to much. AND you cant take back material if your unhappy. Put some clay on top of the piston to check the clearance. Do it without the gasket and if that checks out ok, then you will be good with the gasket in place for sure. Have you considered the l92 head? about 800 bucks for the pair assembled from SDP. Compression will be around the 9.5 area with the dished piston, but you make up for it in flow, 320CFM worth. As for cam, what power you looking to make and where do you want it? I recommend you download Camquest2 from the comp cam website. Enter some of your information and the download is free. It will get you headed in the right direction so you know just about what you want to look for in a cam. Just my .02 cents and some food for thought.

skeeter99

iTrader: (16)

I have considered the l92 top end but really dont have the money right now even though id love to make that much power. I really just wanna get the lq4 slap in the TREX, my tsp pushrods, and prc springs and go! I also have the ls6 intake already and full bolt ons Im a lil curious on how much power this will make me and what kind of track times im looking at. I have an A4 yank 3500 and 3.73 gears. As for hp goals Id like 400+ but the stall and auto may kill that. Ill have a race weight around 3000 for now. Im also going to hit it with a 100 shot

Sales4@Texas-Speed

iTrader: (4)

I would not recommend milling the heads with that cam. Even though there is a dish in the piston I would still think you would have very tight p/v clearance. IMO the L92 heads are not a good fit for LQ4 motors because of the lack of compression combined with the large intake runner and valve. These 3 things will kill low end power and make the vehicle a real turd down low. I would just save some cash and get some 243 heads when you can, IMO compression is worth more then flow on these motors.

70Novaproject

I agree and disagree at the same time. To refine what was said...if you plan go go all out race, high compression would be good. For street use, its not the best choice if you plan to drive a lot. Premium gas (for the sake of conversation/iron block/iron head/carb motor) should be run at 9.3:1 and no more then that. Add aluminum heads and knock sensors and you can go with 10.7:1 at the high end. If you want low compression, then make up for it in flow. Any combo will work, just have to know what your goals are, plan and execute well.

skeeter99

iTrader: (16)

My friend im getting the TREX from is going to get me a lq9 instead of the lq4 so im happy bout that. I would really like to put a set of worked 5.3 heads on now at least install larger valves as long i dont mill them will i have any ptv problems i have seen trucks go mid 11's with this set up so should really make my 3000 pound camaro move what yall think

Sales4@Texas-Speed

iTrader: (4)

I think it will do pretty well. The compression will leave you with a real nice responsive motor. Good luck at the track!

skeeter99

iTrader: (16)

Thanks!!

NemeSS

iTrader: (127)

the lq9 with trex will be a strong combo.
i would mill the heads for even more scr and cut in vr in the pistons. with thinner ls2 gaskets.
this will raise scr/drc, improve quench,significantly improve throttle response,more avrage and peak hp/tq, and improve octane tolerance even with higher scr

fastsspr

iTrader: (49)

How much compression he can have with lq4 and 243 heads?

Sales4@Texas-Speed

iTrader: (4)

With a stock thickness gasket my calculator put that setup at 10.2:1.

LSxPwrDZ

iTrader: (4)

If you really want a cheap route sell your 317s for $200 and either buy some 243/799 heads or buy a set of 5.3 heads and have a cylinder head shop do a valve job and I stall larger LS1 intake valves. Then put them on. The 5.3 heads have a 61cc chamber compared to your 317 heads 71cc. This will give you a 10.68:1 compression. I ran that setup for a little over a year in my street car and a X3 cam and it ran pretty durn good! 11.59@121 NA and 10.57@131 150 shot in a full weight 6spd TA.

skeeter99

iTrader: (16)

I winded up getting a lq9 instead of a lq4 and im going to still run the trex but go with the stock 317 heads for now untill i get some more money and then going to make decisions on the heads either 243 or 5.3 heads just sucks i will have to pull the motor again

gols1go

iTrader: (4)

I have the same setup in mind. I have a LQ4 and i'm contemplating a set of L92 to top it off. I am worried about ptv since my cam is a 232 232 duration with .595 .595 lift. Can this be accomplished without cutting reliefs in the pistons?

TA63

iTrader: (5)

With the LQ9 flat top pistons, the 317's can be safely milled to achieve a pretty respectable compression. They flow about the same as the 243/799 heads.

BOBS99SS

iTrader: (2)

I believe the lq4 comes in at 65lbs heavier than a ls1,my buddy did the swap it was awhile ago but I think that was the weight diff. In his formula