[TimeWarp]

I plan to keep the 555 with twin 475's to a max of 15 psi. I cant even imagine 35 psi.

[charlie66]

Originally Posted by TimeWarp

I plan to keep the 555 with twin 475's to a max of 15 psi. I cant even imagine 35 psi.

lol That would be insane! I bet at 10 pounds you would make more then me.. lol

[TimeWarp]

probably. But the heads flow over 400 cfm at .700, so 10 psi is really moving some air.

[charlie66]

yeah but you will be a lot more efficient and your air temps will be cooler ...

[charlie66]

If you keep it down on boost I think you will be fine...555 ci??? man that thing is going to be hauling a$$

[v869tr6]

Originally Posted by charlie66

Here are 2 pictures I took of the center and the end bolt holes. Center is sunk and the end even though its alone on the end it still is sinking and cracking. So I don't think it matters whether its 2 together or 1. It will still sink.... Those are T - washers sinking....

Could you get the heads off with the T washers looking like that ?
or did the metal crush under the T washers and still hold the stud.

[JSPONT]

Originally Posted by frbformula

Thank you all for your input. I am still about a year away from building my turbo motor as i am in the process of putting a manual trans in the car. It looks like cast heads are a good choice and one i am going to greatly consider.

A question about the aluminium heads. Even at lower boost does the bolt tower between the exhaust ports still become a problem? I am thinking it will take about 10 or less lbs to make my hp goal. Add to that i will most likely want to increase the boost because it will be addicting. So at say 15lbs is there still a concern with the bolt tower or does that issue only come up in high boost applications?

Lower boost you should not have a problem. I think what comes into play at high boost is the EGT's. Charlie66 egt's at that boost is almost hot enough to melt aluminum!! LOL Of course the head bolts that give the trouble are the exhaust head bolts. I run low boost 10 psi now. I have re torqued my heads 4 times, the only time I got movement was after the 1st heat cycle. The last 2 times no movement. Just my .02. I would like to see an out of the box iron head flowing 300 cfm. Killer street piece.

[TimeWarp]

Originally Posted by charlie66

yeah but you will be a lot more efficient and your air temps will be cooler ...

I agree...one of the things that really attracted me to Tom's combo when he decided to sell it...his overall approach was well thought out and high quality stuff. Convertible exhaust gives me a lot more room for exhaust too. And yes, 555 ci is BIG. Which is why on the S475's I'm going to go with the larger 1.32 A/R's. I dont want extra power down low...the thing will have a hard enough time planting any tires with minimal boost from a standing start.

But I looked up a similar 540 ci BBC with the same S475's and 1.32 A/R's.....dyno results were 1800 ft/bs at 4800 rpm and 1800 hp at 5900 rpm.....27 psi. That pull started around 3300 rpm and torque was already over 900 at that point and increasing fast.

[BruceWilkie]

TimeWarp FYI the cv1's have some considerations for higher heat and better cooling built in. Internal water passages and what appear to me to be "cooling veins"' in the bolt boss areas. The other bonus is the aluminum they are cast from(355) and hardness its treated to, has better properties in higher heat applications. AFR uses same alloy(slightly different heat treat), possibly a few others, but most other head manufacturers use 356 alloy which costs less. The convertible exhaust directs a lot of exhaust heat above the center bolt easing heat-load problems there.
Jim Sammons can give you more detailed information as could Bill Anderson.

[GTOGEORGE]

DCI RA5 heads problem solved!



GTO George

[JSPONT]

Originally Posted by GTOGEORGE

DCI RA5 heads problem solved!



GTO George

We are talking budget, not a re mortgage!!

[GTOGEORGE]

So you want to go fast ......you just don't want to spend any money, gotcha! What about safety is that a budget too?


GTO George

[TimeWarp]

Originally Posted by BruceWilkie

TimeWarp FYI the cv1's have some considerations for higher heat and better cooling built in. Internal water passages and what appear to me to be "cooling veins"' in the bolt boss areas. The other bonus is the aluminum they are cast from(355) and hardness its treated to, has better properties in higher heat applications. AFR uses same alloy(slightly different heat treat), possibly a few others, but most other head manufacturers use 356 alloy which costs less. The convertible exhaust directs a lot of exhaust heat above the center bolt easing heat-load problems there.
Jim Sammons can give you more detailed information as could Bill Anderson.

Yes, and I had seen much of what you describe discussed before. I have also ghosted over on the cv-1 website. Thanks

[frbformula]

GTo George, I think those would be a bit over kill for a low boost 800 hp engine.

Basically should i put the money into my e heads or get a set of cast heads and have them done? If the stud pulling through can be easily solved for a low boost application i would just rather use the heads I have as they already have nice parts on them.

[BruceWilkie]

You can use your heads. Have the chambers opened and "softened" some and if need be dish your pistons to get your compression down.

[JSPONT]

Originally Posted by GTOGEORGE

So you want to go fast ......you just don't want to spend any money, gotcha! What about safety is that a budget too?


GTO George

Not everyone has a track car. My car has seat belts (modern) front and rear, cup holders, 2 phone charging ports, cd and mp3 player..... and a turbo to run down the modern muscle cars. Of course the old Pontiac is better looking than the new muscle cars!

[charlie66]

Originally Posted by v869tr6

Could you get the heads off with the T washers looking like that ?
or did the metal crush under the T washers and still hold the stud.

Sounds like you been there don't that! lol! Yes it was a big pain to get off...

That's exactly what it does , just bulges out under the T-washer and wedges the stud...

[charlie66]

Originally Posted by TimeWarp

I agree...one of the things that really attracted me to Tom's combo when he decided to sell it...his overall approach was well thought out and high quality stuff. Convertible exhaust gives me a lot more room for exhaust too. And yes, 555 ci is BIG. Which is why on the S475's I'm going to go with the larger 1.32 A/R's. I dont want extra power down low...the thing will have a hard enough time planting any tires with minimal boost from a standing start.

But I looked up a similar 540 ci BBC with the same S475's and 1.32 A/R's.....dyno results were 1800 ft/bs at 4800 rpm and 1800 hp at 5900 rpm.....27 psi. That pull started around 3300 rpm and torque was already over 900 at that point and increasing fast.

You are going to have a hand full. When are you going to put this thing together?

[GTOGEORGE]

Originally Posted by JSPONT

Not everyone has a track car. My car has seat belts (modern) front and rear, cup holders, 2 phone charging ports, cd and mp3 player..... and a turbo to run down the modern muscle cars. Of course the old Pontiac is better looking than the new muscle cars!

My car has a cup holder!


GTO George