FasterCat

My 67 Cougar is essentially a "new car" from the tires to the ignition switch
... I've been troubleshooting all kinds of things for about six months now.

Motor is 306 roller, 10:1 compression appx, Trick flow TW heads, Trick Flow Track Max Cam,
... "stock" timing is 12 degrees, I've got it set at 14.

One of my latest things "troubleshot" was low vacuum
(turned out that 20 year old edelbrock carb had worn throttleshaft bore ! )

Before replacing carb, vacuum at 650 rpm was 10-12 in hg,
after replacing carb, I am now up to 13-14 in hg.

Is my vacuum still too low ?
(taking into consideration the cam specs = Advertised Duration 283/291,Lift .499/.510)

Car runs awesome otherwise
(feels like twice the power of stock 289 .... which it should be)


So .... do you all think that there could be too much pre-load
on my roller lifters causing low vacuum ?

... obviously, I don't want to "open up" the motor if I don't have to ...

mattdel

13-14 is decent enough for power brakes, if you even have them.

FasterCat

... just spoke with Trick Flow .... they said I SHOULD be getting 12-13 in hg. with the cam and heads I am running. DONE.

... ok, now that my "low" vacuum is sorted, I'll start work on installing a supplementary vacuum pump so my power brakes don't require so much extra power !