[Cliff R]

"I was thinking of a comment from Cliff about one of his customers that ran a RPM intake on a considerably more powerful engine."

It was the RPM intake, and they lost the engine twice on the same rod bearing. It's a high HP set-up, runs high 9's over 135mph, engine makes 735hp. The RPM intake was heavily ported. It was removed, and replaced by a ported Tomahawk with a 2" spacer and no more issues with rods bearings.....Cliff

[Skip Fix]

Cliff what carb on the motor? Q jet or square bore? Which cylinder?

I think Steve C ran a RPM for awhile with no issues with a moderate HP(600+).

[ta man]

New intake in ..as well as three sets of 1233's..time to start prepping.

[Cliff R]

"Cliff what carb on the motor? Q jet or square bore? Which cylinder?"

The owner runs one of our big cfm q-jets based on an early 1980's Chevy truck carb, pretty much the same as an Edelbrock 1910 with the booster rings removed.

Can't remember which cylinder, but the q-jet isn't to blame, he had a 2" spacer on the RPM intake so I doubt if there were any distributions issues, and the problems went away as soon as he changed intake manifolds.

The owner also has a Quick Fuel 1000 cfm carb, but it runs no quicker anyplace than the Q-jet, and the q-jet idles and driver better down the return road, and easier to stage and come up on the brake (foot braked car). So he uses the Q-jet instead of the big Holley, and has now for over 10 years.......Cliff

[Skip Fix]

Originally Posted by Cliff R

"Cliff what carb on the motor? Q jet or square bore? Which cylinder?"

The owner runs one of our big cfm q-jets based on an early 1980's Chevy truck carb, pretty much the same as an Edelbrock 1910 with the booster rings removed.

Can't remember which cylinder, but the q-jet isn't to blame, he had a 2" spacer on the RPM intake so I doubt if there were any distributions issues, and the problems went away as soon as he changed intake manifolds.

Here you said you doubt there was distribution problems so I was confused then how the intake was the cause.

[ta man]

I've had the new rpm intake on for quite a few street miles,car runs a little smoother than before,sounds a little different,power wise hard to tell on the street.Just running the carb on the intake for now no spacers.May be going to the track next weekend testing spacers.

[Cliff R]

"I will be testing intakes this year,I'm swapping a rpm on to see what spacers it likes.Removing the water crossover from both intakes.Both intakes will be port matched to my heads.Then after I have the rpm dialed in for spacers I will test both on the same day at the track."

I'll be looking for those results. I found that my CNC ported HO intake from Dave at SD is just as quick if not a tad quicker than the RPM intake I removed, at least thru the 1/8th mile.

I didn't back to back them, but have compared a lot of runs in similar weather and track conditions, and the car hasn't slowed down anyplace with the HO intake in place, and it's a LOT better fit than the taller RPM intake.

I still liked the RPM and ran well with it, but like using the stock air cleaner, filter, lid and Shaker assembly better, which is all drop on with the HO intake. Using the RPM required a different Shaker and a custom air filter in the opening of it, which I never really liked......Cliff

[Skip Fix]

If it was not a distribution problem what caused the issue with the intake/carb combo?

[Cliff R]

I don't understand the question.

The owner lost the same rod bearing twice, so switched to a single plane intake, same carb, 2" spacer, and the issues went away. This most likely means that the RPM intake was leaning out that cylinder for one reason or another.

I do know that several runners on the RPM are more restrictive than the others where they "lay over" each other in the center of the intake. Still a good intake, and fine for pretty big power. Out past 700hp there are certainly better choices....IMHO.....Cliff

[Half-Inch Stud]

CLIFF,
Is the RPM the better 455 choice vs the Performer RPM? or am I referring to the same casting?

[ta man]

Originally Posted by Half-Inch Stud

CLIFF,
Is the RPM the better 455 choice vs the Performer RPM? or am I referring to the same casting?

Same casting....

[Pontiac Derek]

The RPM is much better than the performer or P4B Q jet flange, Especially ported, you will gain 10hp up top but lose 10ft lbs down low with a 1" open spacer, a 1" open spacer will net you your best et's and you will be right there with a T2 that is untill the T2 is fully ported with a 1" open spacer fwiw

[ta man]

Originally Posted by Pontiac Derek

The RPM is much better than the performer or P4B Q jet flange, Especially ported, you will gain 10hp up top but lose 10ft lbs down low with a 1" open spacer, a 1" open spacer will net you your best et's and you will be right there with a T2 that is untill the T2 is fully ported with a 1" open spacer fwiw

Thanks I gasket matched my rpm intake to my heads,blended it back about 2 inches.I don't think this intake will make more peak power than my Torker 2,but will it make up for the peak horsepower loss with the higher torque numbers down in the rpm range?My torker 2 ran its best with a one inch tapered 4 hole Wilson spacer,you could actually feel the torque difference and throttle response over a one inch spacer.

[PAUL K]

Good luck with your testing it will be interesting to see your results. About 10 years ago I tested the Torker II against the RPM in my 80 Trans Am with a pump gas 462, ported iron heads, 2800 stall and 3.42 gears. My results were;
Performer RPM 11.42 @ 118.65 with 1.673
Torker II. 11.51 @ 118.31 with 1.685

I remember analyzing the time slips and thinking the T2 was a bit slower between the 60 ft and the 330 ft mark.
I had to go up two jet size when I installed the T2 and use slightly larger pump nozzles.


Keep up the good work!

[Skip Fix]

Since my 81 has 3.08s and the 468(0.060 over 455) I have ion the stand is destined to go in it I've been watching closely.

SD ported E heads and Torker II. My hand ported flowed a little better than Dave's CNC, but his was on an EFI one in case I go crazy in the future instead of carbs. I have a Shaker 455 HP 1000 that wil go on it and it just has a Stump Puller

[chuckies76ta]

Just a thought as was mentioned. Monitoring Air/Fuel with both intakes.

Charles

[ta man]

Originally Posted by chuckies76ta

Just a thought as was mentioned. Monitoring Air/Fuel with both intakes.

Charles

Excellent plan...

[chuckies76ta]

Any updates?

Thanks
Charles

[ta man]

No real updates yet..I've ran the performer rpm a few weeks ago...its in the other thread...I'm presently doing a few tweaks..hoping to knock down the et and raise up the mph.Goal is another 11.3x timeslip this year at 120...first one was wind and weather aided..

[ta man]

Weather permitting finally hitting the dragstrip Saturday,and a few more times this year.Just installed a Hughes th 350 with a low first gear set,seems to work good!Replaced front wheels with 15x4's and tires with M/T 165/85/15,dropped 7 lbs each side ,replaced 40lb battery with a Braille 2015 15 lb battery(works great),removed rpm intake and replaced with my Torker 2 which is finally port matched.Also replaced rear wheels which had quite a wobble to them...With good traction and decent air..should run in the low 11.3 range maybe quicker.