Lion roar w/ a Fruit Fly bite!

Okay, so heres my dilemma. My car is a dog off the line! When I get the RPMs up its fine, but I might as well be in park at the stop light. Ive posted here before for this same problem, but think I have a few issues Id like some input on.

First off, I have a 65 Skylark with the 300 V8. Im running 64 aluminum heads and intake and have a 25hp over stock cam with a Carter Competition Series 4bbl. Im running a TH350 with a 2000RPM stall converter. My rear is a non-posi 2:73.

1) After doing a compression test Im showing 110psi in each cylinder which Im thinking is pretty low. What is stock psi supposed to be for the 300 w/ the aluminum heads? I fear that the pistons in the motor are either 2bbl. pistons or 4bbl. pistons for the cast heads. Is there a way to determine what pistons are in the motor by the compression reading rather than taking the motor apart?

2) Is it possible that the 2:73s in the rear are killing me? Obviously theyre not helping the cause any, but would a 3:42 or higher posi make an astronomical difference? Im thinking that even with the 2:73s I should be pulling a good single wheel strip which Im not!

3) Ive also had a huge mix of opinions on the stall converter. Some say that this is what is killing me off the line, whereas others tell me that a stock 1500 stall would kill me even more off the line with the cam. Ive even been advised to maybe go to an even higher stall.. So I have no clue which way to turn.

Before I throw the 300 in the lake to make way for the 455 I invite any and all opinions! o No:

Thanks,
Matt

 

TOSS IT IN THE LAKE, TOSS IT IN THE LAKE, TOSS IT IN THE LAKE, TOSS IT IN THE LAKE!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

 

The 3:42's would make a big difference, and I would go with at least a 2400 stall converter.....nothing lower than that. Big blocks are great......but why toss out what you have when you will end up putting a new converter and gears in even if you went with a BBB.

Mike

 

My stock '65 300-4v Skyalrk with a 2 speed will light em up forever...literally I have to let off to keep some tread on the tires. It is also a non-posi 2.78 (3.08?) Timing or carb maybe?

 

i think your problem may be in the heads. If your engine was originally equipt with the cast iron heads the pistons do not have enough dome and with the aluminum head you have dropped your compression ratio down to low 8's (8.1-8.5). I wanted to put the alminum heads on my engine and talk to a guy that has a 65 he said the pistons are diffrent from the 64 engine this might be your problem

thanks Adam

 

3.42's

Higher stall converter

Get those small potrt heads off the engine and go back to a cast iron 300 head set and intake manifold. The aluminum 300 heads will never match the cast iron ones performance wise.

I work with '64 aluminum 300 heads quite a lot, and all I would change is, make the cast iron '65 thru '67 ones out of aluminum, instead of fighting the ports/chambers in the '64 aluminum ones.

 

I wanted to post the recent updates from my research (along with thanks from everyones help here). The pistons are identical for all 300's from 64-67. The difference lies in whether you are using the 2bbl. pistons vs. the 4bbl. pistons. In the past few days I have found that the 2bbl. pistons are readily availabale and have a pretty significant dish to them (8.5:1 compression ratio - which is even killed more by the Fel-Pro head gaskets vs. steel in the 60's). The 4bbl. pistons (not so readily available) are flat topped and are a 10.2:1 compression ratio. Considering I built the motor myself and remember the pistons vividly - guess which ones are in my motor? You got it! - the dished 2bbl. Needless to say, my cam isn't even working for me at this point.

Once again, let's thank Poston for not only having the 0.30 over 4bbl. pistons, but also having them in stock. Yes I ordered them and they're on their way as we speak.

Additionally, I've found that my cam specs are as follows:
25 hp over stock (4bbl.)
800 RPM idle
1400 RPM kick-in
Therefore, my 2000 stall should be sufficient, but I'm going to a 2200 Pro-Torque which yes, I ordered today also. We shall see what happens. I'm pretty confident though, that my measly 8.5:1 compression ratio (which is actually probably in the 7's with the head gaskets) is my problem.

And the first winter project is the 3:42's!
:TU:

 

so since I wrote this yesterday, I've changed my mind a little bit. I've decided to hold off on the stall converter until I have the pistons changed and the gears in. After talking with Mike on the TA Performance tech line I think I should be running a 3000 RPM stall to really make use of the cam. So instead of putting new windshield wipers on a broken windshield, I thought I'd do this in the most logical order. Motor - gears - then converter. I figure there's no way to tell if the converter is sufficient if I'm, not producing any power right? Again, I'll keep you posted :Comp:

 

Did you remember to take the compression test with the ignition disabled and the carb blocked wide open? If not, the reading will be lower than the actual pressure.

Now, as far as stall goes, when does the cam "hit"? This point is when you physically feel the cam start to make power. "25 horsepower over stock" isn't a big cam, and you wouldn't need a Twilight Zone converter. Stall needs to be 200 rpms over that point. Cam hits 2,500 rpms, stall 2,700.

The heads will continue to be a problem in both port sizing and valve sizing. Iron heads, properly massaged and prepped will fix this issue.

What is happening in Europe now, to the modified 4.6 and larger aluminum Rover engines is, offset ground crank for larger 5.0+ engine sizes, different liners and larger pistons, and the use of 1965 thru 1967 300 IRON CYLINDER HEADS AND LARGER VALVES fitted to the aluminum blocks.

 

What size valves are the boys in europe putting in those '65-'67 heads? What kind of HP numbers are they getting? I would imagine the biggest restriction on a 300 would be the valves... well maybe the intake manifold too!

 

I don't know about the guys in europe but GRNLARK built his 300 and is making 298 rear wheel horse power which is like 315 to 320 at the crank. He is using the aluminum heads with the factory alminum intake (gasket matched of course). I would have to say that is pretty respectable to me. I couldn't imagine what the possibilites would be with a good intake and heads. Anyways for me 300 hores power would be fine. The other thing that people don't seem to mention is the fact with the aluminum heads you can run higher compression on the same grade gasoline and there for make more power, also the weigh less.

Adam