Which electric vacuum pump?

[Injectedcutty]

You know every new replacement engine has to have more cubic inches than the previous engine, I think it's a law somewhere.

That's what I'm hoping to do man! I have everything i need, minus bearings, rings, and machine work to build another 355. However, i would love to up the ante to a forged stroker that will be boost ready, only time will tell!

 

[mobileaudio25]

Or hydraulic set up but more $$View attachment 58254

I've never seen a hydro post setup up close like that. I think around $850 for the whole setup

 

[mobileaudio25]

Or find out what's really wrong with your motor. Low vacuum can be and usually is a sign of weak motor, assuming ( here I go again ) you have you have eliminated vacuum leaks, have your distributor installed correctly, and have your carb adjusted correctly ( idle mixture screws, throttle blade position, idle speed ). Bad / worn rings, burnt valves, worn valve guides, and too much cam timing can all attribute to low vacuum. Even altitude has an effect on an engines ability to produce vacuum. Ex.- I live in Houston, TX ( approx. 100ft above sea level ) but the same engine in Denver, CO ( approx. 6500f above sea level ) will not produce as much vacuum, without retuning. That's one reason the LOW ET / HIGH MPH records are all usually set at lower altitudes. Most records are set at Texas Motorplex ( Dallas ) and Royal Purple Raceway ( Houston ). You have heard of the Texas Mile. Ok, I checked and you live in Ohio, so this is probably not your problem, but it needed to be stated for others reading this in the future. I don't know the condition of your motor, but a leak down test should be in your future. Your cam specs ( I checked the Mutha Thumper line up ) do not warrant a vacuum pump. A vacuum pump is a band aid for your actual problem. Although it may help save your life! LOL I'm not knocking your motor, your decision, or your problem. This is just my .02 cents. Take it or leave it... I will not be offended, and I hope I did not offend you. I back up my statements with the demise of injectedcutty's dead motor, and the fact that your vacuum can did not help. I apologize if I offended you, or injectedcutty. Good luck. James-

Never offended good knowledge there and I have thought about this. Checked for vacuum leaks, distributor is in correctly, had my car on the dyno to set the idle air mixture screws, brand new top end with less than 200 miles, and I believe my cam was installed for low end torque and my total advanced timing is 37 degrees. Bottom end had been rebuilt before not sure when. Motor is strong

 

[86pontiac2+2]

I've never seen a hydro post setup up close like that. I think around $850 for the whole setup

 

[mobileaudio25]

Everything I have heard about the Comp Thumper cams is the price you pay for a radical sounding idle is very low idle vacuum.
Maybe that's why Comps cam dynos show 2 vacuum readings for their popular SBC cams http://www.compcams.com/Pages/401/dyno-sheets.aspx
but show no vacuum readings for the Thumper cam dynos. http://thumprcams.com/

I talked with comp cams and if I remember correctly they said the way the cam was ground there is a good chance for vacuum issues. I feel as if my motor is tuned better than it has ever been. I definitely believe the vacuum issue is cam related.

 

[mobileaudio25]

I just gave comp cams a call and they said them at with that cam it is very common to need a vacuum pump to assist with vacuum for how that cam was designed. It naturally produces a lot lower vacuum due the way it was designed. They assured me that a vacuum pump would fix my braking problem.