Ford Muscle Cars Tech Forum banner

1 - 9 of 9 Posts

·
Registered
Joined
·
15 Posts
Discussion Starter · #1 ·
Ok well we know have oil pressure... But now there seems to be a tapping sound coming from beneath the valve cover. The rockers never were adjusted after the engine was built/ But I thought you didnt have to with hydraulic ones? Anywho I think it might be from running it with no oil pressure. Also the brakes seem to be super hard and not have any power assist as well. We seem to have enough vac but I will re check it. We have a very large cam in there so... Anyhow any advice on this would be great before I move any further.
 

·
Registered
Joined
·
15 Posts
Discussion Starter · #2 ·
Also I wanted to state it has large 42lb/hr injectors and I was wondering if it could be the sound of them?
 

·
Registered
Joined
·
395 Posts
I've heard that a big cam will hurt vacuum enough to force you to swap over to manual brakes... not enough vacuum at low rpm.
 

·
Registered
Joined
·
55 Posts
if its a hydraulic or hydraulic roller cam, no oil pressure with cause the lifter to 'go flat' and not pump up and if run long enough as is, WILL beat in on the cam lobe and once its starts flaking, its all downhill
youre cam IS probaly large enough that its has a lot of overlap and cannot develope enough vacuum....buy or make a vacuum canister
 

·
Registered
Joined
·
5 Posts
Right on, What is your lobe separation on your cam? I am running a 112 lobe separation and my brakes feel normal. When my cam was being built I originally wanted 110 lobe separtion and was advised to go 112.
 

·
Registered
Joined
·
15 Posts
Discussion Starter · #7 ·
The lobe seperation is 114 degrees.. Its a massive pro street cam. Car doesnt do to horrible with it, hopefully adjusting the rockers fixed the problem. Now its getting it tuned and running right, getting brakes, and finding out whats up with the tranny. It doesnt seem to have 3rd or 4th anymore, any ideas? Also could you give some advice on the canister.
 

·
Registered
Joined
·
2,334 Posts
I would certinally check the lift on those two rockers you had to re adjust. if you had lash set right before the no oilpressure you may have rounded the cam at start up and that let the lash go the easy way to sheck is look at the nuts and see if the two out of lash are further down than the others ... if they are i would be pulling lifters!
 
1 - 9 of 9 Posts
Top