477 big block?
Thread Starter
Drifting
Joined: May 2001
Posts: 1,329
Likes: 12
477 big block?
I was fooling around with some ideas and I came up with one I really like:
4.5" bore x 3.75" stroke big block (9.8" deck height)
6.7" rod length
1.205" comp. height pistons
That would give a 1.78 rod/stroke ratio. Which is a bit better than the 327 sbc.
Now this setup wouldn't be really interesting in an N/A application since it wouldn't breath that good so I stacked up a blower on it..maybe a 6-71 or 8-71 with good flowing heads...maybe dart or afr.
If my theory is right, this would allow for a high reving BB with very good bottom end power. I just wonder how high u could rev that thing...maybe 8k?
This is just for fun and I'd like you guys to tell me what you think about this...if I'm wrong, please tell me why so I can learn something. ;)
4.5" bore x 3.75" stroke big block (9.8" deck height)
6.7" rod length
1.205" comp. height pistons
That would give a 1.78 rod/stroke ratio. Which is a bit better than the 327 sbc.
Now this setup wouldn't be really interesting in an N/A application since it wouldn't breath that good so I stacked up a blower on it..maybe a 6-71 or 8-71 with good flowing heads...maybe dart or afr.
If my theory is right, this would allow for a high reving BB with very good bottom end power. I just wonder how high u could rev that thing...maybe 8k?
This is just for fun and I'd like you guys to tell me what you think about this...if I'm wrong, please tell me why so I can learn something. ;)
Race Director
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From: Corsicana, Tx
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Re: 477 big block? (Lohkay)
It's a great N/A combo too. High RPM screamer. I know some guys running it in a 3500 lb car with PG,serious oval port heads, flat tappet cam, 4150 Holleyand drag radials. Ran 9.60's at 139-140 or so.
It's next incarnation was quickly done to allow for rules changes. It got a solid roller and some heads that actually flowed less at the time. But they also got to run real slicks. Same car ran 9.30's.
It is currently being put together with heads done etc and shooting for 900+ Hp in the 8000 rpm range. It regulary runs through the traps in the 8500-8600+ range. Looking for high 8's thi stime out! No bottle, no blower.
Big bore and mega RPM always works well for racing.
JIM
It's next incarnation was quickly done to allow for rules changes. It got a solid roller and some heads that actually flowed less at the time. But they also got to run real slicks. Same car ran 9.30's.
It is currently being put together with heads done etc and shooting for 900+ Hp in the 8000 rpm range. It regulary runs through the traps in the 8500-8600+ range. Looking for high 8's thi stime out! No bottle, no blower.
Big bore and mega RPM always works well for racing.
JIM
Safety Car
Joined: Dec 1999
Posts: 4,148
Likes: 5
From: Roxbury NJ
Re: 477 big block? (Lohkay)
Lohkay, that sounds like a fun engine, but I would worry about the expense of building it. I think you can build a much bigger engine for much less money. Your chosen rpm range and rod length will require some high-end stuff ($$$). If you've got the money to burn, go for it!
-Joe
-Joe
Thread Starter
Drifting
Joined: May 2001
Posts: 1,329
Likes: 12
Re: 477 big block? (Flareside)
Actually flareside, those are readily available parts! I can get that rod length from many manufacturers... the crank with that small of a stroke was a bit harder to find but lunati makes one. The only thing I didn't find are the pistons but I guess its only because I didn't look enough cause its pretty sepecific... I need an inverse dome with that exact comp. height. Worst case, the pistons will be the only custom part in the bottom end.
The valvetrain to handle 8k rpm might be where I'd spend more money that I'd want to tho... didn't look into that yet.
The valvetrain to handle 8k rpm might be where I'd spend more money that I'd want to tho... didn't look into that yet.
Safety Car
Joined: Aug 2001
Posts: 3,892
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From: Pettis Performance 565 with two stages of Nitrous Supply nitrous 1.082, 4.61 at 155, 7.17 at 192
Re: 477 big block? (427Hotrod)
Hot rod knows more about it than I do, but I agree that would be a very good combination. Not only a very good rod to stroke ratio, but because of the 4.5 bore, very high HP possible. It might even be better than a 540 in a vette becasue the 3.75 in. stroke will kill a little of the torque of the line. Rev like a 427 and top end power of a 540, very cool, and better yet very streetable.
Racer
Joined: Nov 2002
Posts: 251
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From: Concord Ca.
Re: 477 big block? (69 N.O.X. RATT)
I think your rods are getting a little too long for the 3.75 stroke crank. A .400 long rod with a 3.75 stroke motor tends to make it a little peaky for anything but a serious drag car. Yes it will turn 8000rpm with ease but so will a stock rod length 454 if you use good parts. Realistically with what you are thinking about it would have to see 8500 to 9000rpm to work and at that point it is the valve gear that is the weak link. Your idea with a .250 long rod would make a killer combo.
Melting Slicks
Joined: Sep 2002
Posts: 2,631
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From: Union City CA
Re: 477 big block? (Lohkay)
Then that would mean that you could run a higher gear more than 4,10 because you could max out at 7 or 8Krpm in your highest gear doing 190mph. This will allow you to get a really good acceleration because you you get higher gears and you rev higher. :yesnod: I think that would be a good engine if you could find a crank.
