Thanks steve, atleast I'm not the only one thinking this way.

Dennis

 

Sorry to interupt.. but could you guys stop the needless fighting and get back to the topic on hand. I'm actually trying to build a motor for next year and can't choose what parts to go with, I've gotten bits and pieces of good info through the fighting..but could we just start talking about the pros and cons.. what rod length.. why 18* heads instead of 23*, which heads.. blah blah.. i for one would like to know how to do what was already outlined.. ~500-600 fwhp 355|383|385|396|402 ... we all know that a 383 WORKS.. yes. . lets try and get the 396 to work now! Lets get the experts to help us figure out why only a handfull have gotten 396+ cubes to work!

 

VK

Thanks for the wake-up call

If you're going to use a SBC engine and you get beyond a certain displacement you run into a wall because of cylinder head restrictions.

It's not there arn't any heads out there you can use - it just gets very pricey. To do the 396-400 engine correctly you have to have a block capable of being bored out to 4.125 - 4.185. Why? - With a 383 you can still use the 5.7 rod or longer if you get a custom piston. So the R/R is 5.7/3.75=1.52. With this rod angle it tends to push the piston against the outside wall very hard, and the dwell at TDC & BDC is very short requiring a much larger head, volume wise, compared to the same engine with a higher rod ratio.

Consider the 396/400 BBC compared to the 400 SBC and you get what I'm talking about. Look at the difference in the heads!!! Then look at the rod length @ 6.125 Vs 5.7 - Now consider the original SBC deaign at 265 CID with a 3" crank and the 5.700 rod which is a 1.9 R/R.

Now look at the deck height difference between the 2 engines SBC=9.020 BBC=9.800 without getting into a real esoteric discussion about engine dynamics it's going to hard to explain beyond this point.

What I'm saying is that if you build an engine that is going to use heads designd for a 350 CID engine how can you expect the same level of performance when you increase the displacement? For me that's a no brainer!

Consequently in order to achieve the same performance that you get from a 350 in a 383/396/400 you have to find a similar engine and copy its basic configuration. Since we know that we can make 500 to 550 with a moderate 350/360 SBC in street trim a 383, to me, sounds unreasonable.

Denny Schmidt

 

THANK YOU

AND Bret what I meant by a "off the shelf head" is a readily AVAILABLE head, A Pro Action head CAN flow 320@.650/.700, yes they need to be worked over..but I do consider it an "off the shelf" head, unlike "to me" an All Pro, Chapman or the like that are a PURE race oriented head.Not "necessarily meant to be street driven


I am in the 23* world because I have a $1000 set of headers sitting here for them, ready to go, that no one else can use.

HEADDOCTOR:

I need 500 RWHP, 500 crank Hp is easy...I need 630 or better at the crank.

As far as the A/c goes the only place I knew I could use it for extended periods is steady cruising, I have the most airflow there, in traffic if need be I will turn it off, but it WILL have it in the car.

Also you guys are overlooking I am at sealevel, in the winter months I have THE BEST air you can have, the best DA you can get, some tracks here go negative DA.

Aslo on the defying the laws of physics quote, I misquted no-one I told you what those cars were doing with the weight and HP they had, you proceeded to tell me you build this efi stock elim car and x car, Ed wrights car is a C efi stock elim car and that the cars down here were defying the laws of physics, don't crawfish on what you said, the cars ARE doing it, What about Brian over on LS1tech AKA ou812z28, the car was in Hotrod Mag, car runs 9.80's with a stock ecm and opti with a 396 and a supervic...explain that one., Ed Wright is not far behind with a 10.16, :LT4 heads and intake and a 383, I have talked to Ed a good bit...I know what his car is. Both cars wegh around 3300 lbs, Ed's has a 4L60E, as does Rick Abares car.

Dennis you didnt "hurt my feelings" it's the condescending attitude you had on the phone, again I am NOt a kid with 2 grand trying to go 10.90 in a 3650lb car I have the means to do it right, I do not want to trash a $1000 worth of headers then spend another $1500 having a set made to work with 18* HEADS, and THEN have to alter the 3.5 inch Y pipe that has been custom made, then change the pistons in the engine, have a 18* specific valvetrain..too much brain damage from where I am now, the 4L60 e aint gonna like being spinned to 7500 rpm with a Fast system either, thats why I want to stay in the 23* world.

With that said, I have said enough on this subject, if anyone wants to help me make this goal call me or e mail me, everyone said Joe Overton, Ed wright, Rick Abare, my buddy Clyde, my Buddy Barnes Brian over on Ls1tech could not do what they are doing, that it was IMPOSSIBLE...but guess what they ARE doing it, and are probably alot more we dont know abaout. SOOOOOOO


Let me know I have the money.

David

 

There's just too much arguing in this thread for me to spend the time to filter it all out and return it to some useful purpose.

If you'd like to start over, without turning it into some a lot of criticizing and arguing with several individuals, go for it. If not, don't.