Can someone verify that I need shims under my rockers?

sizemoremk

Registered User
Hey guys, I have some home-ported BV heads (1.625 ex valves 1.84 in), and the the valves are slightly taller than stock.

When I went out to set pre-load, I tried several pushrods: the stock 7.162, some 7.20, and my adjustable pushrod at a length of 7.250.

When I found zero lash, the "thangie" that the pedistal slides on would not seat on the pedistal unless I used the stock 7.162 pushrod. It would seat, but I got less than 1/4 turn preload on the lifter. (what do you call that thangie?)

So I am assuming that I need some shims under the rockers.

Seems I may need some 7.25 -7.3 pushrods, and some shims. Guess I'll find out the pushrod length when I get it shimed...

Does this sound correct?

Thanks!
 
If the rocker isn't seating on the pedestal itself, but going against the lifter at the same time, then you need either a shorter pushrod or shims. You have to make sure that the lifter is on the base circle of the lobe.

If you have the rocker tightened all the way down, but it is barely preloading the lifter, if at all, then you need a longer pushrod. This was my problem so I had to get 7.250's.

A half turn of the bolt for me was about .045"-.055" and a full turn was about .075"-.080". You need to get some 7.200 pushrods and use shims on them.
 
I got the catwithboost 7.2s, and an adjustable one.

I plan to get some hgher end pushrods, the machinist said I'd need them with my spring pressure and lift.

He was also concerned with the ball end comming off OEM type pushrods... He says he's seen it happen with moderate lift and strong springs.

Is this a real concern, or does my machinist have a brother-in-law over at compcams:D

How will I know what size shims I need? Are there various sizes in a kit? I hope the machinist has some in stock, I want to get the engine put in this weekend if possible... I do use SBF shims, correct?

Also, how can I be sure the lifter is fully pumped up??? I poured some oil on them a little while before I started...
 
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sizemoremk said:
I usually wrap the ball ends with good quality electrical tape, you can get another .20-.50 that way :D
BAAAHAHAHAHA I guess a silly question deserves a silly answer.:D
 
68COUGAR said:
How exactly does one shim a PUSHROD?

68COUGAR
I meant shims for the pedestal's. Man, you take everything too literally, LOL.:)

The part number for the shims needed is FMS-M-6529-A302. They come in increments of .030, .060", and .090". You might need to get pushrods and shims in order to get it to come out right, but you'll see.

The lifters will pump up whenever you start it. I had to start and shut down a couple times to get them to all pump right. They make a little noise on startup, but then goes away after a couple starts.
 
CMac89 said:
I meant shims for the pedestal's. Man, you take everything too literally, LOL.:)

The part number for the shims needed is FMS-M-6529-A302. They come in increments of .030, .060", and .090". You might need to get pushrods and shims in order to get it to come out right, but you'll see.

The lifters will pump up whenever you start it. I had to start and shut down a couple times to get them to all pump right. They make a little noise on startup, but then goes away after a couple starts.


Those are the ones I was lucky enough to find in stock at my machine shop today.

Thank alot!

I hope I don't have to trear things back down and re-adjust after the lifters get pumped up:confused:
 
Better Ford-ese

CMac89 said:
{to 68COUGAR} Man, you take everything too literally, LOL.:)
Yeah I do. It's my humorous way of encouraging more accurate "Ford-speak".

68COUGAR

BTW: That idea of wads of electric tape is Hilarious!!!!!!! I'm gonna recommend it to EVERY Ricer I see on Cruise Night!!!!!!!!!!!! (maybe a few bow-tie-boys too!!!!!!!!! :p )
 
68COUGAR said:
Yeah I do. It's my humorous way of encouraging more accurate "Ford-speak".

68COUGAR

BTW: That idea of wads of electric tape is Hilarious!!!!!!! I'm gonna recommend it to EVERY Ricer I see on Cruise Night!!!!!!!!!!!! (maybe a few bow-tie-boys too!!!!!!!!! :p )


So you have a habit of consorting with ricers:eek: :p
 
How much longer are the valves you used? Did you go with the factory springs too? If the valves are the same length longer as the pushrods (which is not usually the case with Fords) then the distance longer is the exact same as the shim. That is of course if they were all installed the same depth in the seat.

Chris
 
Well the sbc valves (actually ferrea) were a bit taller, and I also have some comp springs with different retainers and spring cups...

So everything is outta wack. I am about to go out right now and see what I can do with the shims...
 
The Mac is right. Be sure to check the installed height of all of the valves. They SHOULD be very close but in the event that they are not, you will need different size parts for each.

Chris
 
I don't quite get wha you're saying, insalled height is how tall the spring is sitting, if that's what you mean, the machinist set that...
 
What he means is that each installed height of the valve could be off around .010'-.020". Some valves sit farther in the seat than others do.

If this is the problem then other valves will need different size shims and all won't be the same. Then again, you'll see. Just keep measuring.

Are you using a dial indicator, or what?
 
I had to return the dial indicator and magnetic base, so I was just going by number degrees of turning the wrench..
 
hmm

I just got done setting all my rockers with the same catwithboost setup your currently running. I am still using stock rockers, but all mine come out to about 7/8 of a full turn on the wrench. So im assuming that mine are all good.

I am using the same 7.200 pushrods that you are using...you would think it would be the same for you... maybe I didnt set them right...

Mike
 
littleboylan said:
I just got done setting all my rockers with the same catwithboost setup your currently running. I am still using stock rockers, but all mine come out to about 7/8 of a full turn on the wrench. So im assuming that mine are all good.

I am using the same 7.200 pushrods that you are using...you would think it would be the same for you... maybe I didnt set them right...

Mike

I got SBC valves though, slightly taller....
 
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