I don't necessarily agree with all of that in "red". Most CF guys that bought our manifold on average saw a 30HP gain at the rear and of course some saw less at 28 HP, but that is a rather huge improvement with just a manifold change. I personally have seen a couple that were more at the rear, 33HP being the largest. However, that 82 CF was completely gone over by Jim and I and was running as good as good gets and that motor was around 145,000 on the clock as well.

As far as 200HP goes, that's at the motor and yeah, it's not a lot to brag about for sure, but if you look at the corvette history from 1973 to 1982, the 82 CF motor was the largest "base" motor HP wise in all those years. There were optional motors in those years that were more, but 82 wasn't one of those years unfortunately.

As far as money spent to go fast goes...yep, it takes money to go fast(er) absolutely no way to get around that. More HP/torq and racing cost cash, bottom line and of course the more you want, the cost goes up. Now, what it boils down to is, how much are you willing to spend, how deep are your pockets and how far down that rabbit hole do you want to go? My rabbit hole 82 is endless I believe, but I enjoy getting ever bit of power out of my motor I can.

It is reasonable to assume that you can achieve 250-300HP in a CF with relatively low cost or should I say for about the same as any other SBC goes, heads, cam exhaust etc... They are all the same. If you want more that that, then you have to step your game up and move to a larger cube motor and much more money, its the way it is, end of story.

The one thing to remember with a CF is, a cam and head change is the way to go, but you have to be careful of how big the cam is that you want. "Don't stray far away and stay relatively close to the stock duration and you should be good". The closer you are to LSA 114, the better, lift is OK as long as your valves don't start having a fist fight with your pistons.

 

First of all, thanks for the thoughtful, intelligent, and logical response! You obviously know much more about the CF than I, and more importantly, have personal first hand experience with these motors which I do not, which to me often counts much more than theory which so often is quoted by many. I think, you and I agree more than disagree. I totally admire the effort to get the most out of the CF or any motor (within reason) to see what can be achieved...I actually really enjoy reading about those efforts by anyone. It is totally admirable to read about folks making the most of the base engine platform than someone who rips out the base engine and drops in a crate 502 BB with 500 Gross HP...just me.

With all that said, you certainly know what can be achieved with the manifold change on the CF and 30 HP as you stated is HUGH! for a manifold only change..no question! (probably mostly due to the quarter size diameter runners that my builder mentioned to me yesterday). I am always very careful about what type of HP I am talking about when referencing that topic since Gross/NET/RWHP are all HP but very different as you know in reality. I am guessing that 28-30 HP gain with the renegade is 20 RWHP that I referenced above at the rear wheels (RWHP) verified by my builder on his mustang dyno (not a dynojet) which as you know more accurately simulates actual/real world RWHP gains and are significantly less than dynojet gains (a lot less according to my source).

Yes, the CF 200 Net HP rating was the biggest "base" HP rating during that era mentioned without an optional engine. The L-82 optional engine though will respond much better and make bigger HP with relatively minor changes than a CF. Case in point, my stock 78 L-82 with 65,000 miles with no emissions, Holley 4175 650 CFM vacuum secondary Qjet replacement carb, 1.52 roller tipped rockers, 2.5 inch duals , no emissions and everything else 100% stock with a weak compression #6 cylinder did 233 RWHP..lets call it 240+ RWHP (GM rated 220 NET HP) if it was 100% healthy. Some simple math says that 240 RWHP is about 285-290 NET HP which is big HP for almost no changes other than letting the L-82 cam and 882 heads with bigger valves than the base motors breathe a bit...just like the manifold change on the CF but with a much bigger result due to the L-82 engine components just have more HP design built (cam and bigger valves in the 882 heads) into them than the CF.

I do not necessarily agree that a cam and head change on a CF will result in the same gains as other SBC from that era. The reason is that the CF has some limitations on the cam, as you mentioned. When I completely rebuilt my L-82 in 2014 with AFR 180 heads and Roller cam (these 2 components were the major deviation from the OEM L-82 and .030 bore), the new L-82 355 has MUCH more HP (RWHP/NET/GROSS) than the aforementioned OEM L-82 with 233/240 RWHP). AFR Heads and roller cam cost at that time about $2,500 which I am guessing produces about 425+ Gross HP today. I just don't see 425+ gross HP coming form a CF with just a head and cam change for $2,500.....

Keep up the great work and thanks again for the discussion points....

 

30 is indeed impressive just shows you how choked the factory one is
would take me EONS of time to get 30hp improvement (rear wheels) from a superram and thats a way better design. Long runners..need volume. Still nice to see support for them anyone else around back then?Thought the CE was the coolest thing even I mean nice decal package, cooler than the X-11 Citation.

 

I personally think at 30 rear wheel horsepower the dyno operator read something wrong or was smoking crack.I think 20 flywheel is possible if you added headers at the same time. Sorry, but as cool as some think it looks it's more outdated than a carburetor.

 

I never got a baseline dyno with the original engine, but if you saw my build thread it would not have been manifold only, so it wouldn't have been what everyone is after. I did a complete rebuild with heads and cam as well as manifold. Also, my original manifold was ported so that also would have skewed the results.

I do wonder if Htown did his dyno comparison...

 

OK, thanks for the post. Hope your 82 is running well.