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Discussion Starter #1
Well I just picked a 454 out of a 85 suburban. The plan right know is to stroke it to 496 as long as the cash doesnt run out first. What heads and stroker kit would you guys suggest to use my goal is to reach around 500 horse or better? Any help with building this engine would be great. Im just starting to get parts together.
 

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I couldn't tell you about the stroker kit. With the heads I would run large oval port open chamber, factory iron ones. Find a set of 049's or 781's. There both up to the task of the power you want.
 

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I couldn't tell you about the stroker kit. With the heads I would run large oval port open chamber, factory iron ones. Find a set of 049's or 781's. There both up to the task of the power you want.
just curious why you would run an open chamber aposed to a closed chamber? compresion is a huge part of HP.
 

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valve unhrouding is the main reason.. the 96cc bathtubs are nortorius in that area.... the 1971 LS^ found a few ponies with the open chambers....like wise the second design L88 open chambers
 

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try to do a roller if at all possible . gm heads keep increasing flow into the .700s so if you can get a roller cam with .6xx lift you will take advantage of some extra flow.
 

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HEADS! Depends on your budget!!

Oval ports are to small for a 496.
If these are the heads you want, why build the stroker kit??


Outstanding quality is Edelbrock RPM XT Rectangular port.

The best is a good argument, AFR's?? Dart?? Brodex???

I am in the planing stages of a 496 myself.
I will use AFR's! I have great results with my 210's on my SBC.


IMO!!!!
Al



Building a performance BBC with oval ports is like installing a restrictor plate!

Just look at the history of the BBC! The bigger the head, the bigger the HP & torque!
 

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Can't argue with you at all. The bigger the head the bigger the $$$$$$$$$.
 

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As for the rotating assy.
Here ya go.
http://www.cnc-motorsports.com/product.asp?ProdID=9245&CtgID=1020
Balancing is an option but I would wait until after mock-up because if you have to flycut the pistons (because of high lift, altered valve angles, altered valve spacing, etc.) you will have to re-balance at an additional cost.

As for the heads, look at all of the 310cc-to-335cc offerings available. On the budget side, the Canfield 310's are hard to beat. If you have the change, the Dart and AFR fully CNC'd 335's and the fully CNC'd Canfield/BMF 320's would be ultra killer.:yes:
RHS, Trickflow, Brodix, Edelbrock and ProFiler all have several excellent offerings as well. Just stay away from the off-shore stuff.:yes:

Play your cards right and 700 HP on pump gas isn't all that hard to get.
 

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A thought for this morning.......... If the hot ticket was closed chambers.... why are all the aftermarket head only offered in 116 to 125 cc chambers?

with all the new computer aided digitizing and dyno hours..... by now some brain trust and deep pock engine builder would have switched to a small chamber... IF it were the HOT TICKET..

the smallest chamber in aftermarket heads I know of in standard BBC 24 degree heads is Edelbrock with 110cc chambers
 

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A thought for this morning.......... If the hot ticket was closed chambers.... why are all the aftermarket head only offered in 116 to 125 cc chambers?

with all the new computer aided digitizing and dyno hours..... by now some brain trust and deep pock engine builder would have switched to a small chamber... IF it were the HOT TICKET..

the smallest chamber in aftermarket heads I know of in standard BBC 24 degree heads is Edelbrock with 110cc chambers
Yup..... Until you get into the steeper valve angle "Spread port" stuff. Then the chambers start shrinking substantially.:yes: But then again, if you really think about it, when you stand the valves up straighter, the combustion chamber and cylinder walls will no longer be in the way as much so the chambers can be MUCH shallower...

Ex:
ProFiler Hitman 12*-------------60cc chambers
Dart Big Chiefs 11*-to-18*----85-to-100 cc chambers
Brodix Big Duke's 18*----------89-to-95cc chambers
Brodix Sweet 16 16*-----------93cc chambers
As well as several other offerings that get a bit smaller. ALL OF WHICH ARE A FAR CRY FROM THEIR 24* BRETHREN...:rolleyes:
 

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Discussion Starter #12 (Edited)
well what are you going to do? street drive it,race it,pump gas,roller cam,flat tappet cam? lower comp with a small cam ovals ports will work all day long(bigger valves and some port work)
The car will be street driven, maybe a weekend at the track somewhere down the line. Pump gas would be ideal as for the cam ,that is open for discussion still trying to plan this whole thing out. Probably running a turbo 400. The car has 3:73-1 gears now. Are the 049s and 781 heads hard to find or is it just better to go with aset of aftermaket perf. heads
 

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The car will be street driven, maybe a weekend at the track somewhere down the line. Pump gas would be ideal as for the cam ,that is open for discussion still trying to plan this whole thing out. Probably running a turbo 400. The car has 3:73-1 gears now. Are the 049s and 781 heads hard to find or is it just better to go with aset of aftermaket perf. heads
On almost 500 CID......I'd go after aftermarket....:yes::devil:
 

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On almost 500 CID......I'd go after aftermarket....:yes::devil:
how much difference realistically between a 049 with big valves and a canfield 310? 50hp?

at only 50hp its not worth the $1500 difference to me. if it was more along the lines of 100hp then maybe.

for reference I have a car mag where they used stock peanut port 236 heads on a 496 and made 520hp. they upped the compression about .75, added tfs/edelbrock/dart heads, and went up to 595hp, or a 75 hp improvemeent. I think 049s with bigger valves would have at least split the difference, or less than a 40hp improvement
 

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Just a thought. If you are staying in the 500 HP range or even a little higher, you could save the money on the stroker kit and invest it in the heads and cam.
 

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how much difference realistically between a 049 with big valves and a canfield 310? 50hp?

at only 50hp its not worth the $1500 difference to me. if it was more along the lines of 100hp then maybe.

for reference I have a car mag where they used stock peanut port 236 heads on a 496 and made 520hp. they upped the compression about .75, added tfs/edelbrock/dart heads, and went up to 595hp, or a 75 hp improvemeent. I think 049s with bigger valves would have at least split the difference, or less than a 40hp improvement
I'd bet the "TFS/Edelbrock/Dart" heads that were used were their oval port replacements..:yes:
The switch to the Canfield (or equivalent) larger rectangular port heads would be more substantial.:yes:
And if the same effort was put into the aftermarket heads that would need to be done to the 049's (in the bowls) it would be even more substantial.:devil:
You also have to consider the overall package. Was the cam in the article better suited for the smaller oval port heads?

Let's face it....if 500HP is really all the O/P wants, then there's no since in stroking it. A 454 will hit that with ease. However, if there's an intent on getting the most out of his parts (hence stroking it) then by all means.....LET IT EAT.:devil:
 

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can't argue with anything said on here. Except for the fact when its all said and done and you have these nice big ol' square ports on your motor and some guys goes by you with some good oval ports, then you'll thnk twice.:D
 

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Another good head out there is the 820 casting large oval port head. Its 112cc open chamber. They are 1971 LS5 heads. Thats what I run, got my pair for $150 :D I prefer them over the 049's and the 781's because you get a bump in compression, and the exhaust valve is unshrouded.

Here's what my chambers look like:

 

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My 049's after a light resurfacing measured out at 110cc combustion chamber size and on my 468 with a zero decked block, .038" gaskets and SRP minidome pistons it puts my static compression at 9.98-1. I was worried there wasn't going to be enough compression as I heard some of the 049's and 781's had 118-122cc combustion chambers, but it looks like I'll be OK. Planning on running the largest VooDoo solid roller but still need to confirm what the dynamic compression ratio will be. 92-93 pump gas.

With a 496 stroker kit and 110cc chambered large oval ports, 2.19/1.88 valves and some bowl work I bet a person could see decent compression with a flat top or mini dome and put down 600-650hp at 6500 if the complete package was right.

The magazine test mentioned earlier used a small cam if I remember correctly, I wish they would have added some 049's or 781's with larger valves into the mix for testing comparisons.
 

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can't argue with anything said on here. Except for the fact when its all said and done and you have these nice big ol' square ports on your motor and some guys goes by you with some good oval ports, then you'll thnk twice.:D
6nova4, are you running oval ports? I've heard many times over that on a 454 based engine there's no power gains going from a good set of oval ports to rectangulars if it's only spun to 6500ish.
 
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