rhoads lifters

has anyone used rhoads lifters on a motor that has to pull vacuum... how much does it help.. i need to pull 15 in vacuum at 900rpm....
and i am pushing my street stock motor as far as the rules allow!

i tried them a long time ago and had trouble with spring psi and upper rpm.that was a long,long time ago.

my motor will be idle to 6000rpm's max

i'd say they'll work for what your doen.your at a good place to find out. it's a little late for some now but you'll get some better ideas from others on here i'm sure.

There are many things (adjustments, internal & external) that may effect the vacuum reading of an engine at a given point. Rhoads brand lifters will offer an increase in engine vacuum at idle speeds, in most applications. Another area, depending on how your carburetor is ported for vacuum ports, with 4V type of carburetors which both primary and secondary throttle blade positions can be adjusted, you can "cheat" the vacuum gauge, depending of course where the vacuum port enters and collects vacuum, by adjusting the primary or/and secondary throttle blade position(s) for the best vacuum reading. If you are using a 2V variety, I'm not quite sure if an advantage is available relative to indicating vacuum.

I do wonder, can the vacuum port's tube I.D. be decreased, and doing so will that increase the reading on the gauge, all things equal? Just a thought.

On the other hand, a dumb-ass such as myself wouldn't think of taking an vacuum reading somewhere else besides the carburetor! Although, the above paragraph could be exercised on an intake vacuum port as well ..... I guess!

Happy Motoring,
Dave.

anyone one else run these lifters??

i have used the and gained between 1 and 2 inches of vacuum.

Can you run a roller? That is what I have ran for the last 5 years in our street stock class. (15@1000) Once you go roller you will never go back.

no i cant run roller

I ran these things in the past and I had a bunch of problems with them. they always floated above 5k rpm and collapsed. switched lifters and all was fine. I will say they did have good vacuum at idle and low rpm, but fell on there face at upper rpm.

paulie wrote:I ran these things in the past and I had a bunch of problems with them. they always floated above 5k rpm and collapsed. switched lifters and all was fine. I will say they did have good vacuum at idle and low rpm, but fell on there face at upper rpm.

same here.

Used them on a 472" mud motor a couple years back. Worked real good for the guy. Made plenty of vacuum on a questionable cam with a SCJ intake, he had to pull 18 or 19" and he turned it over 6000 in a stock class.

Tiger knew the truck.

Bret

Bret Powell wrote:Used them on a 472" mud motor a couple years back. Worked real good for the guy. Made plenty of vacuum on a questionable cam with a SCJ intake, he had to pull 18 or 19" and he turned it over 6000 in a stock class.

Tiger knew the truck.

Bret

i know others who had good luck with them.i think i never had the springs i needed for them to work.are the springs the key on these?

sounds good to me... ITs all about getting every part to work....TOGEATHER

Sorry to bring this topic back up guys, but "dirty intentions racing" sent me a PM asking about a roller profile to pull vac. in his class and I answered him three days ago and it is still in my out box and has not been read, I just want him to know that I returned his request with all information. So "dirty intentions racing" please check your PM's.

Thanks guys.