Underdrive Pulleys

[Ole Blue 68]

I got a new Summit catalog yesterday and noticed they're selling they're own label Underdrive Pulley setup for SBC's. Anybody out there running one? If so, how do you like it and how hard was the install?

[farmtruckIII]

If it is a serpantine set up it should be fine, but the v-belt types are no bueno. I had a set on my 71 El Camino the power steering was hard at low speeds and it would over heat like a big dog in traffic, and it would try to over heat at freeway speeds.

[Ole Blue 68]

Originally Posted by farmtruckIII

If it is a serpantine set up it should be fine, but the v-belt types are no bueno. I had a set on my 71 El Camino the power steering was hard at low speeds and it would over heat like a big dog in traffic, and it would try to over heat at freeway speeds.

Nah, this wasn't a serpentine setup, I think it was for v-belt which is what I'm running right now. Thanks for the info, I don't want to blow this engine up.

[see ten]

I have the March Performance underdrive pulleys on my C/10. It is a V belt system and I haven't had any trouble from it.

[Ole Blue 68]

Originally Posted by see ten

I have the March Performance underdrive pulleys on my C/10. It is a V belt system and I haven't had any trouble from it.

Thanks See Ten, I just priced that set up on Summit and they want like $450 for 'em.

March makes some nice products but damn you gotta pay for them.

[Mudder]

I have the March v belt and I dont think it cost that much. I did have to get a larger crank pulley to lower the temp some. I think mine was about 280 withou looking.

[Ole Blue 68]

Originally Posted by Mudder67

I have the March v belt and I dont think it cost that much. I did have to get a larger crank pulley to lower the temp some. I think mine was about 280 withou looking.

I'll have to look around for a better price then I guess. Nice lookin' engine by the way. I like how you did your PS pump. Have you had any problems with that upper radiator hose? I was thinking of picking one up.

[special-K]

I don`t see much of a purpose for them on old motors.They are a late-model thing for bolt-on power w/o effecting OEM emmissions.Or,at least that`s why they showed up on the market.I`m not bashing them or disrespecting anyone that uses them.Some guys go all the way(and it shows on seeten & mudder`s trucks)and this is another dress-up.I`m just saying there`s better ways to get hp out of an early non-emission motor for the money.
Think of them as a crowning jewel on a built motor.

[Ole Blue 68]

Originally Posted by special-K

I don`t see much of a purpose for them on old motors.They are a late-model thing for bolt-on power w/o effecting OEM emmissions.Or,at least that`s why they showed up on the market.I`m not bashing them or disrespecting anyone that uses them.Some guys go all the way(and it shows on seeten & mudder`s trucks)and this is another dress-up.I`m just saying there`s better ways to get hp out of an early non-emission motor for the money.
Think of them as a crowning jewel on a built motor.

Hey Special K,

This is where I'm at.

Rebuilt 350 bored .060 over with Speed Pro flat top pistons
Lunati Voodoo Cam
Rebuilt stock heads with hardened seats
Performer RPM intake
Edelbrock 1406 carb
Proform HEI Distributor
MSD Plug Wires
Flowtech ceramic coated headers
Flowmaster exhaust

Now, I'm looking at the belts and was consider either swapping over to an electric water pump or giving the underdrive pulleys a try. Any other ideas (besides new heads)?

[special-K]

I don`t know why I assumed you wanted to just change the pulleys.I would say go for the underdrives with the work you`ve done.Is this built,running,and in your truck?Going electric fan & pump will take alot off the motor,but as long as you have p/s,I wouldn`t bother.If you`re working on the motor,heads could use attention.But,be careful on how you match up.Bigger isn`t always better.I`d do some asking before making a move.

[Ole Blue 68]

Yep, the engine's actually in and running pretty strong. I'm just trying to find some extra HP short of changing out the stock heads.

[Mudder]

Ole Blue 68, Thanks.

Have you had any problems with that upper radiator hose? I was thinking of picking one up.

Once the top hose blew off the Thermostat housing. It's pretty slick, but it hasn't done it since. Once you take them off they can be a pain getting back on and to keep from leaking.

[Ole Blue 68]

Thanks Mudder!

[raidermanny]

Originally Posted by Mudder67

Ole Blue 68, Thanks.



Once the top hose blew off the Thermostat housing. It's pretty slick, but it hasn't done it since. Once you take them off they can be a pain getting back on and to keep from leaking.

Had the same thing happen to me with mine. Coolant everywhere.

[Ole Blue 68]

And since were talking about it, here's some progress pics on the engine.

http://oleblue68.shutterfly.com/action/

[Mudder]

Looks good. I am having some trouble with rockers hitting the valve covers. Gonna have to grind or get different ones I guess. Rollers.

[Ole Blue 68]

Originally Posted by Mudder67

Looks good. I am having some trouble with rockers hitting the valve covers. Gonna have to grind or get different ones I guess. Rollers.

Are you running stock length pushrods and 1.5 rockers?

[Werewolf]

The owner of Carolina Auto Masters, whose specialty is the F-body car, told me to not bother with an underdrive pulley set. I just wish I could remember why. I think his point is that the power gain .. if any at all .. wasn't worth both the cost and having nothing work at a stoplight. I've had two LT-1 F-bodies, and each had serious charging issues at idle; the stock pulleys were really as low as you can go. Maybe it'd work out better on your truck.

[see ten]

Originally Posted by Werewolf

The owner of Carolina Auto Masters, whose specialty is the F-body car, told me to not bother with an underdrive pulley set. I just wish I could remember why. I think his point is that the power gain .. if any at all .. wasn't worth both the cost and having nothing work at a stoplight. I've had two LT-1 F-bodies, and each had serious charging issues at idle; the stock pulleys were really as low as you can go. Maybe it'd work out better on your truck.

I talked to a tech at March and they had me change my alternator pulley to a smaller size. This kept the alternator spinning the same as when it had a stock pulley.

[Werewolf]

Maybe it'd work better with these trucks, but it won't work with the LT-1. The harmonic balancer *is* the crank pulley. You have to change the sizes of the other pulleys.