Anyone have before and after hp numbers with heads swap only? What are the other supporting mods? I am just curious to the difference from going from a cam only to heads and the same cam. Thanks.

 

some will say curiosity killed the cat...sure they make a difference...you can get bigger valves /ports ect...you can get them milled to raise the compression..someone else can come in and explain some more..

 

depends on the new heads and the cam your running?

what size cam you got? and what are your other mods?

 

I have the TREX and full bolt ons. I was just wondering the average gains. 10hp? 30hp? or??

 

Went from:
A)390rwhp 360rwtq: cam only
B)425rwhp 387rwtq: Heads, same cam, same bolt-ons
C)480rwhp 418rwtq: Same heads, cam, new bolt-ons

A) TSP231/237, SLP LT's, 3" Custom X-pipe, Stock LS6 intake, usual bolt ons, 4.11 9"
B) Same Cam, TEA Stage 1.5 5.3L heads, Same bolt-ons, same rear
C) Same Cam & Heads, FAST90/90, QTP HVMC LT's, QTP ORY, SLP 2OTL catback, *Degreed the cam, same rear, *further tuning.

* 460rwhp/403rwtq before degree and further tuning

 

i bet if you put some touched up AFR's with a 11:1CR you would see 30+rwhp

 

i bet you would see a little more then 30 hp.I would say 35-40 with the trex.

 

Those seem like good gains. I guess my question to myself is if $2000 is worth 30-40 hp???? lol.

 

Heads can make a nice difference, but they are not all created equal. You will see the big gains with AFR's or ETP's. You can easily see 40 rwhp with the right setup from the above heads I mentioned. You may see less than half of that with some of the budget heads floating around.

 

With the T rex the ETP will be your best option unless you have valve relief's in your pistons. The ETP heads are made on a 11 degree angle and allow for much more piston to valve clearence.
I say that is your in a 6 speed car with the correct boltons 45HP could be gained from the ETP heads. I would do a set of the 215's and go with a 61-62cc head to raise compression. You will be going from a stock head, to a top notch head, and at the same time increase compression by about a 1 point. Looks like your in CA or else I would suggest a 59cc head but with 91 octane that would probally be to much compression. Also the power throughout the RPM band will increase quite a bit. The ET heads flow better at .400 then stock heads flow period.

 

Huge difference if done correctly.

 

Yeah, I am in Ca. I would want to stay with pump gas 91 octane. When I had the heads off last time, I went ahead an did the flycutting on the pistons (intake side only) for a future application, so I think I am safe there. I am also running a th400 tranny and shorty headers (I have space limits)

Would I be wasting my money to have my stock 853 heads ported?

 

^
You can send them to TEA for their Stage 1 program. Will provide you some great low and mid lift flow numbers, along with near 300 cfm @ .550-.600. PTV clearance does not change any. $1000 for the job. Probably less by sending them your heads.

Stock valves, exhaust flown w/pipe
.100 73/--
.200 144/---
.300 109/149
.400 252/189
.500 283/219
.550 296/232
.600 294/245

 

I agree. If you already have the pistons notched I would mill them at least to 64cc's and personially I would go 62cc's.
Z06 vette are all over California with 91 octane and 64cc heads. 10.8-11.0 should be okay with the proper tune on 91 octane. But if your scared then go 64cc and run 10.6:1 give or take.
TEA does a hell of a job.
Those shorties gotta go............T rex+ shorties ='s
LOL

 

^ SHORTY HEADERS AND A TREX! I Did not see that.

Buy a THUNDER RACING CheaTR cam!!!

 

Everything is *** backwards on this thread.

 

Thunder Racing Custom "CheaTR" Camshaft - 214/230 .601/.578 117 LSA. Off Idle-6800 RPM Power Band. Broad power range. Works well with stock exhaust manifolds and catalytic converters. Stock like idle. Minor tuning required on automatic transmission cars. Due to the fast ramp rate of this camshaft, the use of 1.8 rockers is not recommended.

 

oops.. but wow, 20 rwhp jus by degreeing the cam... hmm.. maybe ill take the time to do tht when i do the cam in mine.

 

It was redgreed, retuned, and plugs were changed. These steps were done by the car's new owner. A man who has full access to a dyno and edit, and a full service shop (he's a sponsor on this board).

 

i mean i knw that degreeing a cam will yield gains in power and efficiency but damn thats a lot. i guess hes jus tht damn good