[grivera]

based on the performance you described I'd bet the internals are what you think they are, fwiw

[AdamIsAdam]

Originally Posted by grivera

based on the performance you described I'd bet the internals are what you think they are, fwiw

That's sort of what I'm thinking. The bottom line is that it runs strong (when tuned right), certainly strong enough for around-town spirited driving and smokey burnouts for the kids (yes officer, it was for the kids). I want to get down the 1320 in the 12s, even 12.99, and I'd be VERY happy. I'd also like to see 400hp / 500ft lbs on the dyno at the rear wheels too.

But most importantly, is to run reliably and smoothly -- and to last a long time without exploding

[ta man]

Originally Posted by AdamIsAdam

That's sort of what I'm thinking. The bottom line is that it runs strong (when tuned right), certainly strong enough for around-town spirited driving and smokey burnouts for the kids (yes officer, it was for the kids). I want to get down the 1320 in the 12s, even 12.99, and I'd be VERY happy. I'd also like to see 400hp / 500ft lbs on the dyno at the rear wheels too.

But most importantly, is to run reliably and smoothly -- and to last a long time without exploding

400 hp at the rear wheels will easily put you in the 12's..I wouldn't fret over the 557 block much..unless you are launching the car with full traction all the time it will last.

[HWYSTR455]

46 heads with screw in studs are of 2 varieties, one is 98 cc, the other 89 cc. And usually, they are bigger than advertised by a few CCs. Your deck height is .010, with a 17cc dish, 4.190 bore, 4.250 stroke, you are in the 9.3 - 9.8 range. Which makes more sense.

The info on the head flow sheet is bogus, the guy just plugged something in to do initial calculations, it's the flow data that is important.

.

[AdamIsAdam]

Originally Posted by HWYSTR455

46 heads with screw in studs are of 2 varieties, one is 98 cc, the other 89 cc. And usually, they are bigger than advertised by a few CCs. Your deck height is .010, with a 17cc dish, 4.190 bore, 4.250 stroke, you are in the 9.3 - 9.8 range. Which makes more sense.

The info on the head flow sheet is bogus, the guy just plugged something in to do initial calculations, it's the flow data that is important.

.

ohhhhhhhhhhhh!!!!!!!!!!!! That makes much more sense!!! And makes me feel better that it's not such a high CR. THANKS!!!

Just curious, how come you can't calculate the exact CR? Are you missing some piece of info?

Also, these heads were converted to screw in. Not sure if that helps you any.

Is there anything else you can tell me from the paperwork that I either had wrong or didn't know? This is great stuff. It's like tracing a family tree all the way back

[HWYSTR455]

If they originally were non-screw in studs, they are in the 96-98cc advertised range, so it would be closer to 9.3 SCR. And no, there's no other info on the docs that you really need to know, all standard stuff.

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[PontGuy]

Lets give him the benefit of doubt- he probably just didn't know about the weaker 557 blocks, at least when he started the project. I didn't know about them until becoming active here. The receipts all look good to me and the guy that ported the heads obviously assumed they were going on a 400 with flat top pistons.

The big question I have is why the engine was built with so much compression- I get at least 10.5 and that's assuming a .020 deck height. It seems to be working OK and making great power but it must be on the razor's edge. I definitely would not put much vacuum advance on it. And figure on upgrading the cooling system to get the temps down especially on hot summer days.

Can't speak to longevity of the block since I have absolutely no experience there.

[STEELCITYFIREBIRD]

FWIW, I am putting together a 400, same exact block,75 on valley... Original block that came in my 76 formula. I have an earlier 1970 block that I am saving for a long stoke motor.
At the (dirt) racetracks they use a cube checker in the limited classes, measures amount of air displaced by sweep of one piston. Not sure if anyone else does that.

Someone probably has a good reliable way to measure the stroke assembled, that may chime in. I've never done it, but I am sure it can be done.
Pulling the right plug may allow you to see in a cylinder to see if it has dished or flat top pistons in it, that might be very telling.
I'd have to know weather me and him need to have a chat.
The block isn't a reason to have a "chat", the rotating assembly would be.
Don't despair over the block, just try to verify what is inside so your not chasing your ass tuning it.

She is a nice ride, just don't hammer her too hard!
No 4g holeshots!

[AdamIsAdam]

cooling system consists of an aluminum radiator and a two speed electric fan from a Taurus. Last summer it worked well. Tstat is 180*, so I"m told. And I run Evan's waterless coolant for some added protection.

When you say no 4,000 RPM wholeshots. You mean don't dump the clutch at 4k, right? Because I do like a long, smokey burnout once the tires are spinning already, but that shouldn't stress the engine too much since the tires are spinning.