[mrsbadbird]

Say you had some parts lying around and decided to do a semi-budget engine build.
Mostly street thrasher, few times a year racer. Aluminum heads are for later, this is a "what's lying around build," just no cheap short block parts. Understand, this is theoretical. Here we go:

'72 400 block +.040, zero decked
Scat 4340, 4" stroke/3" main/BBC rod journals
Callies 6.7 or 6.8 rods (open to input)
BRC 17cc dished pistons
Ported, modified chamber (79cc) #670 heads
Performer RPM (blocked heat xover) with QuickFuel 780 - street use
Crower solid FT 284/292, .525/.551 (1.65 rocker) 112 LSA
Doug's 1 7/8" headers, 3 1/2" collectors.
TH350 w/ 3000 - 3200 converter (input)

435 cid, 9.5:1, 3200lbs, 3.90 gearing.

What say you, gurus?

...also...
For a weekend trip to the track, what carb and intake manifold would you stick on it?

 

[BILL BOWMAN]

What do the heads flow?
That cam duration is adv. Not @.050 right?

 

[mrsbadbird]

About 240 at their best. Not an SD CNC job.
And yes I listed the adv, the duration at .050 is 240/248.
Also, the lift figures I calculated from Crower's site using 1.65 rockers, and I did not subtract the .022/.024 for lash. I don't think the numbers they list have lash factored in either.

 

[BILL BOWMAN]

450ish

 

[mrsbadbird]

Sounds just fine to me, I'd be pleased with that. Would you suggest a different camshaft?

 

[BILL BOWMAN]

Sounds just fine to me, I'd be pleased with that. Would you suggest a different camshaft?

Not very agressive, what are your goals,expectations.

 

[mrsbadbird]

Well...I have a Tempest that is really a pretty nice car. The boss (read: hubby) and I have both decided we would really like to have a muscle car we could actually drive to do cruises and whatnot...you know, looks decent and has a good stereo but will still "get some." I would like to run it in 11.60 index or 12.0, which are both classes available around here, BOP weekend, etc. If I got serious about racing I would do a purpose-built car. No interest in dusting the wall with the one I have, I've had it a long time and I'm pretty attached to it. I don't want it to go the way of his Firebird ala SCSN7. I also am not loaded with dollars either.

I just figured with cast heads a ton of lift was pretty much wasted so I didn't get nuts with the camshaft selection, but it's still up in the air. I'm open to suggestion, as long as the suggestion is not a BBC...:yawinkle:

 

[BILL BOWMAN]

I am really partial to hydraulic roller cams, good power, reliable, pretty much maintenace free.
Also wondering about 6.7 and 6.8 rods, nothing wrong with them, maybe cheaper than the stock length 6.625, but you would have to order pistons to match.
I can understand wanting to use parts you have lying around. And I would never, ever suggest a foreign motor.

 

[ozone eater]

i would put some edelbrocks on it and bump up the compression to about 10.5-1. would be a solid 550hp street engine on pump gas.

 

[mrsbadbird]

Also wondering about 6.7 and 6.8 rods, nothing wrong with them, maybe cheaper than the stock length 6.625, but you would have to order pistons to match.

Well, there are a few reasons for that, but mainly 1: availability and selection. 2: hard to find a good aftermarket forged crankshaft that doesn't have BBC rod journals...though with only making 450hp, an aftermarket cast piece would probably fit the bill too, just not sold on that idea.

Rollers are cool but that's a lot of extra $$$$. Not against it though. Thanks for replying, I appreciate the advice.

 

[mrsbadbird]

i would put some edelbrocks on it and bump up the compression to about 10.5-1. would be a solid 550hp street engine on pump gas.

I'd love to do that, but between buying the heads and the port work they would need...It's not completely out of the question, just wanted to thrash what I have. I make well under 50k a year and I have bills to pay too lol.
You do make a good point though, I've tossed it around. People on racingjunk want 2k and up for their used stuff...

 

[BILL BOWMAN]

Well, there are a few reasons for that, but mainly 1: availability and selection. 2: hard to find a good aftermarket forged crankshaft that doesn't have BBC rod journals...though with only making 450hp, an aftermarket cast piece would probably fit the bill too, just not sold on that idea.

Rollers are cool but that's a lot of extra $$$$. Not against it though. Thanks for replying, I appreciate the advice.

You dont need an aftermarket crank. Many stock Pontiac cranks are very strong. The 421 that I am redoing for my Catalina was in my GTO (avatar pic) Stock crank, it went 9.90 @ 3600#
Butler performance has very reasonably priced freshed cranks you may want to look into.

 

[mrsbadbird]

Thanks for your input. I wanted to build the short block really strong in case one day I decided to use it for a more race-only type build and spring the extra $$$ for some badass aluminum heads. But, that would be a while off. I had a buddy who offered to sell me his KRE heads for a decent price but he's still using them so I don't know if that will ever go through.
I know a lot of guys run stock cranks and have good luck with them, even with a little spray.
9.90 is gettin some for a heavier car, you must know what you're talking about Nice to hear you did it with a 421, I have a soft spot for the smaller cube Pontiacs, hence wanting a 4" stroke.

 

[11613-bentwrench]

Bill is right about factory cranks , we used to rev to 7800 in a 413 ( .070 + 400) in SS with a standard N crank , they would last 2 seasons before the cracks would show , no special conditioning needed , check them with a fine tooth comb before you use it , we mag and x ray ours, just make sure your balancing is spot on and lighten the pistons as much as possible .

 

[quick1sr]

your crank should be fine, mine is a 455, but it has been sprayed with 250-350 for most of its life...cast heads, hydraulic cam .407 lift. Ran 11.90 best on motor, 10.20 on nos everytime...thrown together engine, trw flat tops....go have fun with what you have, keep it simple

 

[ozone eater]

i been 8.89 at 153 with stock 400 block and a 455 crank cut down to 3" mains. small roller cam. drove it all over the place and that was with alum rods. kaufmans sell a great head for your application.ill try to find the ad on fulpers website about my car.

 

[mrsbadbird]

your crank should be fine, mine is a 455, but it has been sprayed with 250-350 for most of its life...cast heads, hydraulic cam .407 lift. Ran 11.90 best on motor, 10.20 on nos everytime...thrown together engine, trw flat tops....go have fun with what you have, keep it simple

Damn, that's gettin some too...that's awesome, I appreciate your thoughts on this. What does that beast weigh, is it still 3800lbs give or take?
I am kind of alone in my project if you get what I'm saying...I'm surrounded by some very, very knowledgeable BBC guys and I learn stuff from them all the tim, and hubby is great at helping me with bodywork and teaching me to weld..but they don't really "get" why I won't build a BBC...although I understand their argument too, and they make valid points.
There are some pretty serious Pontiac guys in the area too, although most of them are stockers. There's a guy who races a bird around here and I like picking his brain, but he's gone a lot.

I may go with that cast crank afterall, being that all I wanted was a stout engine to beat the hell out of I think that will work, and it would save me a couple hundred I could put elsewhere.
The Navy needs to pay more, lol...

BTW, what would any of you recommend for a converter other than what I guestimated?

 

[mrsbadbird]

i been 8.89 at 153 with stock 400 block and a 455 crank cut down to 3" mains. small roller cam. drove it all over the place and that was with alum rods. kaufmans sell a great head for your application.ill try to find the ad on fulpers website about my car.

Thanks for your advice, I have been tossing around the idea of KREs for a while and I may end up going that route just for the sake of not haveing to be as "careful" in tuning and fuel for the street. The 670s can work pretty well, but I have a feeling I'm not immune to the speed bug and I'm going to want to keep going faster.

Ken Brewer has his car for sale cheap, it's not my favorite body style but would probably be a good first serious racecar for me, I have dealt with him a lot and I know anything he sells is what he says it is. Trying to sell hubby on it, it's my money but you know how it is, racing is a team effort. I had my poncho when we met and I was used to having to fix it by myself, but it's really nice to have help.

What is the profile for the hydraulic roller you used?

 

[ozone eater]

Thanks for your advice, I have been tossing around the idea of KREs for a while and I may end up going that route just for the sake of not haveing to be as "careful" in tuning and fuel for the street. The 670s can work pretty well, but I have a feeling I'm not immune to the speed bug and I'm going to want to keep going faster.

Ken Brewer has his car for sale cheap, it's not my favorite body style but would probably be a good first serious racecar for me, I have dealt with him a lot and I know anything he sells is what he says it is. Trying to sell hubby on it, it's my money but you know how it is, racing is a team effort. I had my poncho when we met and I was used to having to fix it by myself, but it's really nice to have help.

What is the profile for the hydraulic roller you used?

it was a solid roller. i think it was around 284degrees at .050. 700 lift. the most hated man in the pontiac world bruce fulper did the heads and cam specs. they made great power. the main thing is to have fun. that is what it is all about.

 

[Hooter]

Thanks for your advice, I have been tossing around the idea of KREs for a while and I may end up going that route just for the sake of not haveing to be as "careful" in tuning and fuel for the street. The 670s can work pretty well, but I have a feeling I'm not immune to the speed bug and I'm going to want to keep going faster.

Ken Brewer has his car for sale cheap, it's not my favorite body style but would probably be a good first serious racecar for me, I have dealt with him a lot and I know anything he sells is what he says it is. Trying to sell hubby on it, it's my money but you know how it is, racing is a team effort. I had my poncho when we met and I was used to having to fix it by myself, but it's really nice to have help.

What is the profile for the hydraulic roller you used?

Ace is practically giving that car way.