Thumpr vs disc brakes?

[BYGDDY]

Anyone have any experience with running power brakes with a Comp thumpr? Comp websitre say's not a great idea but have heard of some people on the interweb using it with no issue's. Just wanted first hand advise if it's out there. I will be doing a drum to power disk conversion in the spring and needed to knwo if im looking at buying a vacuum canister? (i know squat about them btw so any advice there would be great as well)
thanks
Dave

[TC]

Re: Thumpr vs disc brakes?

Dave what kind of vacuum is the engine pulling at idle??

[fahrenschnell]

Re: Thumpr vs disc brakes?

I am using a Comp Thumpr on the Van I am working on and am adding a vacuum canister just to be safe.....they are supposed to pull decent vacuum at idle so it should be alright.

Seth

[BYGDDY]

Re: Thumpr vs disc brakes?

Dave what kind of vacuum is the engine pulling at idle??

Dunno, cam, lifters, heads, intake, carb, headers, shift kit, guages, steering wheel, shifter, all sitting in trunk. Just collecting parts right now, once i have everything i will start assembling. But im ordering the disk brake kit from Impala bob's in the next couple of weeks.

[BYGDDY]

Re: Thumpr vs disc brakes?

I am using a Comp Thumpr on the Van I am working on and am adding a vacuum canister just to be safe.....they are supposed to pull decent vacuum at idle so it should be alright.

Seth

Thanks Seth, is teh vacuum canister just that? A reserve canister or will i need a pump as well, i know i can get the canister from Jegs cheap but not sure if that's what i need or not, i know diddly about them.....

[fahrenschnell]

Re: Thumpr vs disc brakes?

Yes....it basically stores vacuum from when the engine is making vacuum. No pump needed.

Seth

[DanStokes]

Re: Thumpr vs disc brakes?

In the 70's these canisters came stock on many Ford products - they look exactly like a tomato juice can w/o label. If I remember correctly they had a valve of some sort to keep the vacuum from bleeding off when the engine wasn't making any. Anyhow, this would be a good score if there's a salvage yard near you with older stuff.

Dan

[BYGDDY]

Re: Thumpr vs disc brakes?

In the 70's these canisters came stock on many Ford products - they look exactly like a tomato juice can w/o label. If I remember correctly they had a valve of some sort to keep the vacuum from bleeding off when the engine wasn't making any. Anyhow, this would be a good score if there's a salvage yard near you with older stuff.

Dan

So worst case senerio comp has them for about 60$, not super expensive, i thought i needed a pump and all that crap so i was concerned....thanks...
Dave

[TheSilverBuick]

Re: Thumpr vs disc brakes?

In the 70's these canisters came stock on many Ford products - they look exactly like a tomato juice can w/o label. If I remember correctly they had a valve of some sort to keep the vacuum from bleeding off when the engine wasn't making any. Anyhow, this would be a good score if there's a salvage yard near you with older stuff.

Dan

So worst case senerio comp has them for about 60$, not super expensive, i thought i needed a pump and all that crap so i was concerned....thanks...
Dave

Dan's right. My T-bird has no less than five vacuum cans in it. As one is kind of pictured on the right.


What I would do is grab one of the bigger vacuum cans, drill two holes in it and using a grommet and Brake Booster Check Valve in one drilled hole to the Intake or Carb base (where ever the Booster would get it's vacuum). Then with a nipple of sufficient size off the can to the Booster. Then the stock port on the can, can be used for your heater/defroster vents.

And I wouldn't worry about a vacuum pump until you've tested the can out with engine vacuum. I would think one or two good engine deacceleration should give adequate vacuum with the Thumper series cams to make good use of the vacuum can resevoir.

[SpiderGearsMan]

Re: Thumpr vs disc brakes?

just fix the drum brakes - unless you are going to run lemans or something

[SpiderGearsMan]

Re: Thumpr vs disc brakes?

a better question - WHAT torque Convertor are you running ?

[yellomalibu]

Re: Thumpr vs disc brakes?

Depending oh how you plan on driving, you may not need the cannister.

I had a comp cams 292 flat tappet (244 @ .050) which had very little vacuum at idle. It wasn't a problem to me... just expect to have a firm pedal sometimes. If you find it's too firm, or possibly dangerous... get a vac. can.

[BYGDDY]

Re: Thumpr vs disc brakes?

just fix the drum brakes - unless you are going to run lemans or something

Drum brakes are new, they work great....once :o.....figure with a 375-400hp motor it would just make sense to have decent and repeatable braking, i live in the country and do alot of highway driving, we play "dodge the deer" out here alot and don't need to hit the pedal and have the car pull, lock up one wheel or anything weird...

[BYGDDY]

Re: Thumpr vs disc brakes?

a better question - WHAT torque Convertor are you running ?

was going to order this week actually, holeshot 2400. Why do you ask?

[58yeoman]

Re: Thumpr vs disc brakes?

Or just go manual brakes.