Proform Carb?
 

I've alway used a standard Holley carb and my car has a Barry Grant Holley on it now. I have some of my customer asking about the Proform carbs. Can you guys tell me the pros & cons of the Proform carbs? Thanks

TS1955

I tried one of thier center sections years ago could never get rid of an off idle stumble. Tried everything was not impressed. But have heard of others that had good luck. If someone is going to get a bad one it would be me.LOL

I've got that same problem now on the boys mustang, proform center section. I've tried everything but throwing it in the thrash.

On the flip side I put one a car I ran years ago, ran like a top right out the box.

Since you guys have run only the center section and have had trouble, do you think it's a problem between the Proform center and the standard metering blocks?

TS1955

It's very possible.

my soninlaw has a pure proform 650 on a 302 and it has a bad off idle stumble we need help with that if anyone has fixed yours maybe you can tell us what you did.
Andy

I have a brand new Proform 850 gasser with Quick Fuel Technology on my 388 circle track engine with huge cam, in a lightweight modified car.
It works great... but then again, I am almost never coming off idle, I am hitting the green flag drop rolling out of turn four at about 4500 rpm...

reply
 

Well, a few things to check for here;
1. float levels, engine running on level ground, yeah I know everybody does it!!! but on a Proform carb the fuel should be right at the bottom of the plug window or see thru plug if you have them, if not, get a set they work great for monitoring your float levels.
2. You may have to play around with the cam on the throttle linkage and slow down the 2ndarys a little bit.
3. Does this carb have jet extensions in the rear bowl? if not, better get a set of those too! Does it have the notched float in the rear bowl? it should!, if not send it back to Proform and tell them to fix it right :x
4. Fuel pressure, you should have no more than 7psi on a gauge past the reg. and before the carb.
5. IF, your carb has the secondary throttle shaft adjustment on it, this needs to be almost identical to the front shaft setting as this is a very touchy carb if not set right. Loosen both screws up after recording on some paper where they are now before you change them, and at least you can go back to that setting if all else fails. But, close both sets of butterflys, and then turn each one in, 1-1.5 turns in or clockwise on both shafts, fire it up and adjust them to get the highest vacuum reading you can obtain, it does have a vacuum port on the front or rear of the bottom plate right? my 950 did!! and then just play around with the idle until you can get a good idle and put into gear and it should not drop in rpm by more than a couple hundred rpm's and stay running, then pop it back into nuetral and if it sounds to high in the rpm's, well adjust the 4 corner idle screws again and then go back and readjust the throttle shaft screws until it likes your screw driver :D

I tell yea, the Proform 950 I had, was the BEST 4150 carb I ever had and my engine wanted more carb after that size too!!! big block 454 12:5:1 comp. with oval port heads put my 3600lb Elky at a best of 11:02 @ 123 mph with a 4.56 gear. I never did a jet test on it and I should have as I could have broke the 10's for sure, and I had an air cleaner on it too, big 14 inch x 4 incher.
6. idle screws, give them a full turn out from all the way in, and if it won't stay running turn all of them another 1/2 turn until it starts and runs by itself then adj. as needed. Great carbs if you can tune them right :wink:

John

My dad has ran them religiuosly for a few years not on his late models with no problems at all

I went with a prform main body on my holley in my mustang. It never would idle after that. I asume the base plate did not match up, so I wold not reccomend changing just part of the carb. All or nothing.