Cylinder Heads

[visuvious]

Well finally got the car all ready for corn! Fortunately before we could do a pull. We noticed a miss, so tore it down and ran some compression testing. No compression at all in number three. After dropping a camera down in there, found an exhaust seat had fell. Luckily it didn't fall all the way down.

So now it is time for a rebuild or just some new kick ass heads. Any recommendations are welcomed.

 

[Teej281]

Since youre going into the engine, get new pistons and port them heads!

 

[Tifosi2003GT]

how many miles on motor?

If it has low miles and the valve didn't hit the piston why not just get a nice set of p&p heads

 

[50 Deep]

Livernois

 

[03Steve]

Stock set worked by Todd Fays.

 

[visuvious]

The car only has 17k on it, it didn't have any damage to the piston. I'm just going to leave the shortblock alone for now. I was thinking about getting the livernoise stage 3 heads and some cams. I have the whipple 3.4 with behemoth inlet on it. Just made some other changes as well. Switched over to the 105 lb injectors from lethal. I also went with the vmp 110mm billet housing and the SCT ba5000.

The car will be on E85 as well. So I am looking for the best options for the car.

 

[04cobrawhine]

rebuilding those heads is very expensive. i just paied $2400 to get all new seats, guides, seals and lifters installed. its cheaper to just by a new set of revised heads. only reason i didnt is because they are P&P and flow over 330cfm.

 

[cbr repsol]

^^ yeah your right with the port work u have done i would of rebuilt them as well.

 

[visuvious]

rebuilding those heads is very expensive. i just paied $2400 to get all new seats, guides, seals and lifters installed. its cheaper to just by a new set of revised heads. only reason i didnt is because they are P&P and flow over 300cfm.

Dang that's just shy of new heads

 

[AntiHeightPunk]

why not get new pistons since the motor is coming out and raise the compression?

 

[visuvious]

why not get new pistons since the motor is coming out and raise the compression?

Money! I have a 98 Cobra that I am working on as well.

 

[AntiHeightPunk]

pistons will cost an extra 500 bucks and give you much bigger gains that ported heads and cams

 

[Parts-is-Parts]

pistons will cost an extra 500 bucks and give you much bigger gains that ported heads and cams

You lost me on this statement. :??:

 

[Ironhand]

You lost me on this statement. :??:

He is saying that putting high compression pistons will give you better gains then ported heads.

Also, good pistons cost more then 500 dollars. A good set of pistons and stainless rings cost almost a grand for the set.

 

[AntiHeightPunk]

He is saying that putting high compression pistons will give you better gains then ported heads.

Also, good pistons cost more then 500 dollars. A good set of pistons and stainless rings cost almost a grand for the set.

my cost for pistons may be off, however if he is running E85 raising the compression on this car will not only make better gains. The gains will also be cheaper per hosepower.

 

[Ironhand]

my cost for pistons may be off, however if he is running E85 raising the compression on this car will not only make better gains. The gains will also be cheaper per hosepower.

It depends on setup.

Bumping compression say from 8.5:1 to 10:1 will only increase engine efficiency by about 4.3%. Thats a rough number tho. And boost can be dialed up or down cheaper then pistons. Yes they may only cost x amount, but labor time, and any other upgrades cost alot of money compared to just raising boost or switching blowers. So technically no, the cost per horsepower will not be an advantage because a good solid built shortblock will still cost you over 4k plus the labor time to install it if you dont do it yourself.

Also a fair amount of power from worked cylinder heads comes from the pistons being increased in size and helping to unshroud the valves. But doing a .20 over bore adds even more expense or using a BOSS block adds to that expense which inturn bring the horsepower per dollar rate down compared to a blower or pulley swap.