Boy I know that's wide open....


Here's what I have:
9to1 compression, stock G heads, Comp cam 42-229-4, Performer intake and AED 750HO carb, MSD dist. This engine is fresh and never been started yet. I'll have it in a 71 442 4spd with power brakes and air, 3:42 gear.


Questions are:
I know my ram air air cleaner set up won't work, but has anyone modified a base or something to make it fit?


Would a stock manifold and "Q jet" do as well as the above?


Anyone have any experience with this Comp cam and how does it sound at idle?


Last one,, any guess on HP expectations?


I know its a lot of questions, but I'm just trying to figure out where I want to go with this engine before I install it.


Thanks much guys!

 

In a 455 that cam will sound tame.idle vacume around 18 inches @650.on a mild build up a stock intake and a recalibrated quadrajet will make the same power as the holley.do you have headders it helps a little.I have had a few mild 455 with a camshaft under 220 to 216 @50 run 96 to 101mph in the 1/4. With the 4 speed and your rear gear,power won't be a problem if you can tune the car carburetor and ignition.you are already ahead of most a good gear and exhaust is the first thing I recommend before ever going to engine.

 

Thanks grampy, I will running headers and was hoping for a little lumply lump at idle. I'm going to break in on a dyno so we will be tuning it. I thought with a good q jet I may get as good result as the race holley. Plus, I'm just driving it on the street. Lol,,, looks like I may have a new carb and intake for sale...

 

Theres nothing wrong with your carb and intake. The base of you aircleaner can be modified to adapt to the ram air. People get creative.

 

That's what I was wondering. I figured someone had already done that. Just would like for someone to chime in with info. And maybe pics..?

 

Anybody have any experience with that Comp Cam?

 

Bump!.... Anybody have any more info. to share?

 

335hp at the rear wheels with a well tuned Q-Jet. I'm guessing you have a ram air hood?

 

Yep,, ram air hood and air cleaner. That's why I'm trying to figure out if I want to keep the aftermarket intake and carb or not. If it will improve performance then I will figure out a way to keep the ram air cleaner by modifying the base or something but if there is no real "seat in the pants" improvements, then I may go stock and forget all the extra work.

 

I have seen cars run in the 11s with the stock intake and quadrajet.as for that comp cam the only ones I have put in are 280 they were the most popular when the comp mag line first came out.I have put in a 262 xe in a 68 400 it was rebuilt all stock but had a comp 280 camshaft with a 308 gear and stock converter.the guy who owned it said it was doggy down low justs to putt around with and had me install xe 262 it ran a great the guy was happy.driveability and throttle responds was improved good idle and more low end tq.

 

"had me install xe 262 it ran a great the guy was happy.driveability and throttle responds was improved good idle and more low end tq."

Something to do with the '68 400 engine's tractor-esque bore/stroke ratio?

 

Thanks for the responses guys...



For some reason,, I thought,,, hey, take a flash light to the spark plug hole and see if I can read the numbers on the pistons. Well, I did and I have L3092F .40 pistons. If I have searched correctly, it looks like these are low compression pistons..Ugggh!. I'm really kinda bummed about that because I had another 455 low compression engine once before a was very disappointed with the power or lack of. Again,,, I'm looking for a good beefy sound at idle with good power like a big block Olds should be. I'm thinking now,, different pistons and cam? What do you guys suggest... Oh and I will be running long tube headers and pump gas. Also, I have decided to go with a stock manifold and modified Q jet. And,, I think I posted I had G heads before but they are GA.. Thanks a bunch!

 

The "bang" you hear with a performance cam is actually the combustion process. No compression, no bang.
To get what you you're looking for you'll need more compression and a corresponding cam. There are lots of pistons options, from just ok to real good, depending on your budget.
Decide what you want and can afford and go from there. We'll all be happy to help.

 

Would highly recommend CutlassEFI for any of your parts or questions. He has helped me so far through my build up. Thanks Mark

 

Sounds more like you have TRW/speed pro 2390's pistons. which are low compression.
Now if the machine shop who built it, maybe they deck the block and milled the heads to increase the comp, but it will still be below 10 to 1, I would say closer to 9 to 1 at the most.
if you make changes be sure to measure the deck height of the pistons, so you know where to start.
Cutlass EFI can set you up with anything you need.

Gene

 

Sounds like I'm thinking in the right direction from your answers. Thanks.


To save money, could I buy the same brand pistons but higher compression and use the same rings on each cyl.? The engine has never been fired.


At this point, I don't know who built the engine. I'm going to attempt to contact the owner who had it built to see if he can give me his name and some more info. ( I bought the car from a 3rd party and he don't know)


CutlassEFI would you send me a pm with your contact info. please? Thanks

 

Done.