Vintage Mustang Forums banner

1 - 11 of 11 Posts

·
Registered
Joined
·
6,031 Posts
Discussion Starter #1
I am looking to upgrade my cam, and I do not want to buy new rockers at this point in time. How much lift are stock rockers worth?

This isnt so much an upgrade as a last ditch effort to get rid of an annoying tick in the valve train. I cannot find any header leaks, and this is the only other thing I can think of. I am fairly sure I did not break the cam in properly. The engine runs like a top, but for some reason I have this TICK! I tried to ignore it, but to no avail. I must win this battle!
 

·
Registered
Joined
·
6,911 Posts
I ran a .530 lift comp cam with oem's with the crane roller fulcrum kit....

If the noise isn't exhaust, it's probably an oil pressure issue
 

·
Registered
Joined
·
6,031 Posts
Discussion Starter #3
I dunno how.... I got plenty of pressure.

Would my pressure go to pot if I lost a gallery plug outta the front of hte block? that is the ONLY thing I can think of that could be causing this...
 

·
Registered
Joined
·
795 Posts
Not only do you need to consider the rocker, you must consider the springs. Make sure you get matching springs for your cam grind.
 

·
Registered
Joined
·
10,587 Posts
Just went down the oil pressure road with another VMFers' 351W...turns out the transfer passage soft plug at the top back of the block was missing. His pressure never topped 25 psi.

Rocker arms should be good for .530" or so lift, depending on spring pressure used...at that level, service life will be reduced, especially at higher rpms...in the old days, there was a replacement pivot for SBC's and SBF's (Windsor type rockers) that had grooves in it for better oiling which helped it to live at higher spring pressure and rpms.

The likely symptom of too much camshaft/spring pressure for the rocker will be snapping rocker studs off...
 

·
Registered
Joined
·
7,671 Posts
I have the Crane fulcrum kit in my 460 pickup, uses the factory rockers.... Contains the same needle bearings as full roller rockers.... A good "middle of the road" upgrade for stock rockers... Couple of years ago, was $130.
 

·
Registered
Joined
·
6,031 Posts
Discussion Starter #7
Ummm... huh? Transfer passage plug? I replaced everything I took out (kept the old to be sure). The only plug at the back of the block was the one at the end of the cam (besides the gallery plugs)

My oil pressure is high according to my stock gauge, but I am going to invest in a aftermarket gauge here shortly to be sure.
 

·
Registered
Joined
·
10,587 Posts
On the Cleveland block below, take a look at the intake manifold sealing rail at the back of the block.....on a Windsor, that's where the transfer passage soft plug is...

http://users.abilene.com/~dkelly/hotrod/images/motor/351blk.jpg

I don't recall if Clevelands have the same setup....hope I didn't confuse you..*G*
 

·
Registered
Joined
·
6,031 Posts
Discussion Starter #9
I cant see from that picture, but from memory, there is nothing there on my block.

Let us assume it is not there and I have a W... that would flood the lifter valley yeah?
 

·
Premium Member
Joined
·
765 Posts
I have stock rockers on a Boss 302, which is really just a 351C 4V Quench head with funny water passages. It also has the screw-in studs, guideplates and all that, but I believe it uses the same sled rocker arm regardless.
I am running a full up TransAm cam with the original rockers (not TransAm rockers) and I'm well over .650 on lift.
Ask me again next week when I put in the Harland Sharps, sitting on the bench. I'll see what the lift really is (Looked 5 years ago and I forget the exact number).
The PO probably took off the rollers he had on there right before he sold it, cause with this kinda lift (and spring pressure) I go through a lot of pushrods. And only because the pushrod ends up going through the rocker arm. They are real tough to remove after they've done this.
On the other hand, it makes for cool workbench art.

I figure I'm loosing over 25hp because of the stock rockers; the sled design is inefficient and gets worse with high spring pressures at high lifts. My water temp should go down too -- less heat.

Since I gather you have press-in studs, do the Crane pedastal conversion for rollers; it's not a lot of money and fairly cheap HP.

BTW, too much side clearance on a valve can also cause a ticking, somewhat like a bad lifter, though not so loud.

BossBill
 
1 - 11 of 11 Posts
Top