I have a 1964 Cutlass I am working on. Paint and upholstery are now done. Switched the transmission to a 350.
I acquired a stock 1967 Toro 425 which was rebuilt to stock (including the stock “sunken manifold” )with the exception of a Perfect Circle 229-1644 cam my friend had - he says it is a “W-30”cam. Carb is a quadrajet.
I also have a second 1967 Toro 425 I traded for - it was rebuilt with a different cam ( don’t know the profile) ,has a 384439 manifold, and Edelbrock 1411 carb. I took both motors to a local engine dyno facilty . Stock ignition on both motors .Pictures are attached for the best runs for both motors .


My Motor’s manual rates this motor as 385 HP and 475 Torque . I am curious if these ratings were overstated or whether further tuning is required . Thanks for your assistance .

 

Factory numbers were gross HP and TQ. 71 and all afterwards were net HP, accessories take horsepower to turn. There probably is more in both motors. Stock iron intakes and exhaust manifolds?

 

Why did your Dyno operator stop the pulls so early? Both were still climbing.
Timing? Fuel?
Remember, as noted early figures were gross numbers, no mufflers etc., AND we had waaaay better gas back then as well.

 

Did you tune on the Q-Jet during the dyno session? What altitude does the dyno sit at?

 

Thank you for the input.
W and Z manifolds on both motors
Edelbrock motor has iron 384439 intake.Quadrajet motor has stock 1967 Toro intake
Do not know why he stopped the runs when he did - concerned with safety of motor ?
Elevation here is 243 feet above sea level
He changed the metering rods and secondary hangers on the Quadrajet, which increased HP by 15 . Taking out the fuel filter in the carb increased HP by 20.

 

The Toro motor would not idle less than 1200 RPM and has low vacuum. The Edelbrock motor has a milder cam , will Idle at 800 RPM and has more vacuum. My Cutlass will be a street car and has power brakes ;would it be better to go with the Edelbrock motor in the Cutlass ?

 

You have to ask why the dyno operator stopped the runs when he did. m
I thought the total timing was to much, if I am reading the dyno printout correctly.
If you told dyno shop to just dyno the engines, thats about all you got.
Your problems are in carburetion and tuning, as I see it.

If thats in fact a cam comparable to a "W-30 cam", it should be able to idle about 850-900 RPM's. This is assuming he was referring to the 308 degree "W-30 cam". It would also be a little lower on vacuum and would need a bit higher stall torque convertor. Did anyone degree in either cam when rebuilding ?
I am sure others can chime in with info too.

 

He ran both motors with more and less timing - best results were these two runs .
I do not know if the cam was edged in on either motor.
The specs I have for the Perfect Circle cam in the Quadrajet motor are 244 degrees duration, 475 lift, and 110 lobe centers.
Thanks again for the input/advice .

 

Your perfect circle cam is a copy of the W30 4spd cam. .475@328 degrees duration. It was ground on a 110 lobe separation and had 244 degrees of duration at .050 lift. It won't make vacuum for power brakes.

 

Thanks for confirming the cam profile . I think I will put the other 425 in my Cutlass , which has power brakes .
What gains can be expected with a manifold change ?
What gains can be expected with headers ? Are they available for a 425 in a 1964 Cutlass ?

 

Yeah, run the second one. You are probably best to run the motor as is. Maybe run the Qjet, depends on which carb you like better. You would have to check hood clearance with a Performer or other taller aftermarket manifold before doing the swap, depends on the planned air cleaner setup as well. I believe headers is either shorties like Thornton or very expensive American Racing stainless headers are your choices. If you can still find a set of the cheap Chinese stainless full length, they may be worth a shot to try. What trans? Get a mild torque converter upgrade, if an automatic, helps launch a lot.

 

Your Toro motor is just set incorrectly for that cam. A plain Jane Qjet won't work with that cam. Putting a Performer and a 750 Holley on it would totally change those numbers and allow it to idle correctly .

 

https://cliffshighperformance.com/pr...piston-springs
Talk to Cliff, the lightest spring might be what works with the big cam.

 

Thank you guys - the non W-30 went in yesterday . Working on all the pumps, brackets, pulleys , etc
The street car is a hardtop . I have a 1964 Cutlass 2 door post I would like to set up for the track . Think I will use the W - 30 motor and get a Performer and Holley.
What is a safe RPM for these 425 motors ?

 

There is no magic number. How far you can push it depends on the parts and how it is built. You will probably need to shift before you will see max RPM. More details for that engine would give us a better idea.