Hey all,

Recently had a 400 machined by TMeyer Inc.

I'm currently running into an issue when shimming it, at .80 I'm still quite a bit off a good pattern. I am using an adjustable pushrod set at the proper preload

I have to shim it to .160 to get a nice pattern on the tip, but by then I have completely lost the pedestal.

I'm thinking the heads have been machined too much, causing the valve to come up and now I'm having to compensate a ton with shims. I have .020 and .040 shims.

Here is no shims on #1 intake


I'll post more pictures of different shim combinations. If needed

NOTE: I've been doing the tip sweep with proper lifter preload, should I bottom out the lifter (I have adjustable pushrods I've been using) to simulate it being pumped up and get the true tip sweep?

 

if you are using an adjustable pushrod, than that should cancel out/if any, the machining on the head surface where it meets the block. If you had assembled the block and heads and then used the standard pushrods, I could understand this problem if indeed the heads were done, but if it was that bad then you would not only have issues with pushrods and rockers, but also with the intake manifold alignment/bolt-up.
There are calculations (especially for these canted valve type heads) where you can only take so much off before you have to start machining the intake face.
The installed height on your valves also determine the pedestal height for your rockers and by the sound of it they may have been machined previously?
I know that it isnt ideal, but there are shims for the top of the valve stems but this may not help your geometry either.
Are they your original heads, and if so what did you run on them? It would have been obvious then also. What rockers are you trying to use now? I have been reading a lot about rockers and some have absolutely hideous alignment issues!

 

Not sure what you mean " I am using an adjustable pushrod set at the proper preload " ? You don't know the proper length at this point & preload has nothing to do with finding push rod length at this point. You have to remove the valve springs and put light checking springs on to find the length. You can not run it through a sweep with the valve springs on, it will depress the lifter plunger and cause the problem you discribe. You have to be very careful that you don't depress the lifter's plunger when you turn the crank over. After you find the right length you add the preload figure the the measurement, preload has nothing to do with finding the right length.

 

Here it is, three days after the original post....have you figured it out yet? I don't want to offer any insight if you're good to go.

 

I need more (and better) pics to see what is going on.

I am assuming you are using hydraulic tie-bar roller lifters (something like Lunati or Comp)?

Like this:



You need to "pump them up" or use light checking springs (or a pair of solid lifters) to get a true pattern.

I filled the engine with oil, used a summit racing tool that you put on your drill which connects to the oil pump drive-shaft, and I had my wife run the drill in reverse to keep the lifters fully pumped up while I did my pattern checking by turning the crank with my breaker bar for two full (720 degrees) of revolutions. That is the easiest way. Checking springs are a PITA, and who wants to destroy a lifter pair to make a solid checker setup?

Tool: http://www.summitracing.com/parts/me...FWho7AodgDEAHg

I needed .080" on all pedestals to get the proper pattern and I ended up using pushrods that are 9.100" in length with my Aussie 302C Quench heads. 9.050" would have also worked in my case...I was kind of "right in the middle" of spec.

Are you torquing the Scorpions down to spec before performing the check?

The easiest way is to call Tim, give him your credit card, and have him send you a giant assortment of push-rods in various lengths. Use what you need, return the rest.

I pumped the lifters up as described, did my very best measurement with my pushrod length checking tool and a long sliding caliper, added in the desired extra pre-load length (.040-.080" is recommended...for simple math strive for about .050"), then installed the pushrods I *thought* were appropriate with no shims initially, then checked my pattern. I then shimmed...re-checked...re-checked length (with the shims) using the adjustable length push-rod tool...re-did the math for proper pre-load...went up .050" in pushrod length. I used a Sharpie like you are doing to read the pattern.

It took a while...I went no shims...then .020 then .040 then .060 then .080 and .080" was the ticket (two .040" shims stacked).

Keep in mind that the hydraulic plungers in the lifters have between .180" and .210" of range (Tim can jump in - I don't know the exact specs on the Lunati's I run) so even at .080" of pre-load - if you went that much - you still have .100" of range left before they would bottom out.

Don't be shy about calling Tim - assuming you purchased the parts from him - he is VERY helpful. Don't waste his time if you didn't. He prefers talking over typing. I even did face-time with him using my i_Phone when I was stuck initially.

I am thinking your adjustable length pushrod tool is flexing a bit or your lifters are compressing - you MUST pump them up to get a good reading. That's why I say use the tool to get a best guess (Try it first with .080" worth of shims under the pedestal) and then use real pushrods in a length equal to what you measured plus .050" pre-load.

Tim told me that most of the builds he has been doing have needed .060" to .080" of shims - there *might* be an issue with Scorpions design...they might need a slightly taller pedestal mount base that goes between the pedestal and roller-rocker (That is my my opinion based on my build and what Tim has seen and told me as of late).

 

I went digging for you. You can see that even with .080" of shims...I still wasn't perfect...but close enough!:







All done!

 

crsmiffy - The heads are rebuilt, they are not the original heads I sent in. The original heads I sent to TMI had been rebuilt several times and there was an issue because the valve guides had bronze inserts on top of being oversize.
I never set up the original heads, just pulled a running motor from a buddy's parts truck.
I was using some Scorpion SCP1024BL 1.73 BBF roller rockers. Yeah I talked to Tim over at TMI and he said they've had it with this PN, they're going with a new PN because of the fulcrum being too short.

mark a- I meant to say that I'm running a dummy lifter, and I have my pushrod set a zero lash, so I am getting a full sweep on the valve tip. I know what you're saying about the checking springs but for me the dummy lifter was easier as I don't have an air compressor to hold the valve up.

Filthy beast - I talked to Tim and he talked to Scorpion so I should be getting an updated rocker

Dimora - I'm using a dummy lifter. I've an old dizzy I made a priming tool out of, but I like the dummy lifter better. I had an extra set of lifters to destroy so it all worked out.
I did torque em down.
That is also what I am doing with my adjustable pushrod, except I will be double checking preload after setting up the geometry.
I don't know the specs on the lunatis lifters I'm running off hand but that sounds right.
I'm sure Tim has my number memorized at this point.
I'm running dummy lifters so there is no way they are compressing. Tim believed me, and when checked with a stock stamped rocker arm, the pattern was right on to .040" off, which Tim said was fine and expected because of the known issue with this PN rocker arm.
He told me the same thing, and they are now doing away with that PN. I needed ~.160 on average to get an acceptable pattern.
Your .080 is how mine looked with .160 under the pedestals

 

I recently done a rebuilt on my 400. I use the adjustable push rods lenght checker and a black marker. My head were shave and my block was l deck (shave).I used roller rocker from a 460 with a conversion kit to accept adjustable roller rockers set up. You need to colour with marker the tip of the valve. Then adjust the valve and rotate 2turns on the crank.the remove the rocker and look st the tip of the valve to see the wear patern.adjust the rods to have the wear patern in the midle of the valve tips.close to the intake is too short close to the intake is to long.adjust to have it in the midle to have a perfect geometrie.

 

.. Sounds like you are going about this backwards... using checking valvesprings, adjust the rockers/shims to give a good sweep on the valve tip over your cam's valve lift range... and THEN use the adjustable pushrods tool to find out what length pushrods will make that all work... or use the proper pushrods from a TM assortment that fit (if any)... add .20" - .030" to that pushrod length to preload/compress the pistons into the hydraulic lifters properly so they can self-adjust for temperature changes and very slight break-in wear...

 

I got all the instruction from crane cam.my head are rebuilt with new spring and valve. I didnt mention but i use preload and adjust the rocker before.

 

BuzzLOL i re-read and i understand what you mean by looking on pics with shims under the rocker. i didn't even know they made shims like that. What i used is a conversion kit and they give me a spacer that come flush with the pedestal (have no place to install those shims because it's flush with the 2 tips and have a push rods guide on the spacer). gona try to show you a part number and picture . I used 460 rocker 1.7 instead of 1.73. I have a space between the rocker and that guide plate that act like a shim. this set up required guide plate because the rocker can go left and right. not the same set up as scorpion. did the scorpion required harded pushrods ? because mine does.

Hope i didn't done something wrong!

 

http://www.summitracing.com/parts/cr...view/make/ford

http://www.summitracing.com/parts/cr...view/make/ford

This is what i used on aussie heads with new springs to match the cam and one piece stainless steel valve from Alex parts with keepers and retainers,
new valve guides(the rebuilder said only need guide on exhaust side, heat wear them faster ?), 3 angles valves job. shave the stock aussie heads just for clean up.