huge cam

[71BlazerFrederick]

I am running a Beck 454 with 11.3 to 1 compression so not much vacuum to run my power brakes with. Has anyone used one of those vacuum pumps before? If so what kind?

Thank you!

[GMC-YA68]

everyone that I have seen with this issue has swapped over to a hydroboost set up.

[71BlazerFrederick]

I have looked into that its just 4X the cost is all or I would do it now. I think if I drop a $1k on something I'd probably put that towards a 350 engine swap and solve a few problems and improve the street ability of it my Blazer. I can stop running premium gas, overheating, and mileage.

[cleszkie]

I run a CVR vacuum pump. Maintains a minimum 15 psi and maximum 20 psi at the booster. Its plumbed in line with the engine vacuum hose and only comes on when needed. Got it through Summit Racing for like $300. There are cheaper pumps out there, but why risk it?

[71BlazerFrederick]

Great and what did you do with the vacuum line from the motor? Just put a breather on the valve cover then? I also have a vacuum canister so do I need remove it or will it help maintain vacuum?

[cleszkie]

Originally Posted by 71BlazerFrederick

Great and what did you do with the vacuum line from the motor? Just put a breather on the valve cover then? I also have a vacuum canister so do I need remove it or will it help maintain vacuum?

Vacuum line runs from engine to vacuum pump. Another line runs from the vacuum pump to the brake booster. The vacuum pump serves to supplement engine vacuum when it falls below 15 psi if there is not already enough vacuum in the booster reservoir (at high rpm, even a big cam can make this vacuum and prime the booster). So don't just get rid of the engine vacuum line and rely only on the vacuum pump. There is no need for the vacuum canister once you install a pump. It won't hurt anything, but I doubt there will be room for both a canister and a pump under the hood, and who wants all that extra tubing.

[mtully79]

Originally Posted by 71BlazerFrederick

I have looked into that its just 4X the cost is all or I would do it now. I think if I drop a $1k on something I'd probably put that towards a 350 engine swap and solve a few problems and improve the street ability of it my Blazer. I can stop running premium gas, overheating, and mileage.

I only use 93 octane based on a recommendation from a mechanic buddy, is this the norm or do you all run 87 on yours?

[71BlazerFrederick]

Yes, I am running 93 octane because its such a high compression motor. I have a fair amount of room under the hood even with the big block so if the canister would help then I'd like to install it. I just want my brakes to work better like they should so I feel more confident driving it in traffic instead of worrying about running over the Prius that whips in front of me. In time I might swap out and go a new hydro setup which will clean up the area a lot.

[Mike C]

Automatic in your truck? Best mod I ever made on my truck with the SM465 was ditching the big cam. Torque curve now right in the sweet spot for the 4 speeds gear splits. For your 454 I'd be looking into a cam with no more than 220 degrees at .050 and possibly less. My 331 now has a cam with 210 at .050 replacing the 228 at .050. And if you can swing it, hydraulic roller all the way.
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