[StevenC]

I have a SBC with a XR270HR roller cam.

Advertised Duration:

Intake: 270
Exhaust: 276

Thank you.

 

[StevenC]

is it acceptable to say 14?

 

[techinspector1]

You can say anything you want to, but you'll need 18 to run power brakes properly.

 

[StevenC]

This could be in a boat, my lawn mower, living room furniture... it doesn't matter... I just need to know what kind of vac I should have on it. Its a fresh built motor, and I do not think its putting as much vac as it should be.

 

[red65mustang]

techinspector, the power brakes booster has a check valve, all but the most radical motors do show 18"Hg above idle and 25"Hg on a down shift

"blip" the throttle once after starting the car and the booster is holding plenty of vacuum

working correctly, not leaking, it should hold the vacuum for 24 hours after turning off the motor

stevenC, 14Hg is enough to do some break in miles, I don't even try to tune till 500+ miles......rings and valves are "seated"

 

[StevenC]

It has molly rings and a roller cam. I would like to get it tuned in. I also need to find out why my roller rockers are so damn loud.

 

[xntrik]

This could be in a boat, my lawn mower, living room furniture... it doesn't matter... I just need to know what kind of vac I should have on it. Its a fresh built motor, and I do not think its putting as much vac as it should be.

With dual plane intakes:
That cam in a 265 SBC V8 will give you about 7 at idle.
That cam in a 502 BBC V8 will give you about 19 at idle.

Single plane intakes figure about 2/3 of that.

I can't believe I am wasting my time answering you.

 

[red65mustang]

how many miles till the moly rings seal depends on what hone finish was put on the cylinders,
what you can do now is go back and check the torque on the intake bolts since it has gone thru a (couple of) hot/cold cycle(s)

your posts read like it might be wise to give it a rest for a while?????

I haven't got a clue why your rockers are noisy....you have given "0" info about the motor

 

[StevenC]

sigh... the type of replies I expected.

xntrik, if you are going to be that much of a dick then you shouldn't have even wasted your time.

red65mustang, I was not asking for a reason for the loud rockers it was just a statement.

 

[red65mustang]

I wish you nothing but peace and happiness Steven, cause you did just get deleted out of my life......

 

[xntrik]

sigh... the type of replies I expected.

xntrik, if you are going to be that much of a dick then you shouldn't have even wasted your time.

red65mustang, I was not asking for a reason for the loud rockers it was just a statement.

Hey, I am THE ONLY ONE THAT ANSWERED YOUR QUESTION.

It depends on the engine.



# 23 on the IGNORE list.

 

[johnsongrass1]

Put me on there too.