7.3 IDI Turbo Knock -> Engine Pull and Rebuild

[Macrobb]

Plastigauge requires a compression to make a measurement, which is the opposite of what you want when checking piston/valve clearance, if you have so little clearance to compress a plastigauge between the valve and piston, your valves are probably already bent from turning the engine over.

No, the principle is exactly the sake. You are compressing the play-doh to whatever thickness clearance you have. Plastigage is the same, it's just of a calibrated diameter and designed for much smaller clearances.

Also, you *don't* need to worry about bending a valve from valve-piston contact on an IDI - the valves are perfectly square to the bore.
What will happen instead is you'll destroy your guides and/or bend pushrods if you are running the motor with it too tight.

 

[IDIBRONCO]

I had no idea. Thank you for sharing.

Me either. I'd never heard of the thicker sizes before.

 

[MICHAEL MICHAUD]

Just waiting for my engine kit and block to be done, handling odds and ends like frayed wires, lapping the valves and what not.

Got around to installing my electric fuel pump today. Put together an ugly as hell but functional (yes I know they are sad excuses for welds) bracket out of pieces of bedframe that I fould by a dumpster.

Fabbed up an H style bracket large enough to allow the hood to close. Wired it up sort of how its done in the tech articles. Two of my pins were swapped is all.

Fits snugly against the wall. I put some 1 inch thick foam underneath for it to rest on and reduce vibration and it works like a charm.

Will find out if it works when i get the engine back in.

Tried to keep the location tight and aft so that I can put a cold intake on it when i have some more monies.

You must be registered for see images attach

You must be registered for see images attach

You must be registered for see images attach

 

[MICHAEL MICHAUD]

Got my block back today and the last of the parts I was waiting on. Sleeved cylinder looks great and is thankfully the correct cylinder. Cam bearings installed properly as well. They did not resurface the block at all.

Installed the Comp valve springs. All my intakes were at ~1.8" already. The exhaust valves on one head needed .060 shims, The other head 3 used .075 (1 60 + 1 15) qnd one just used .060. That is crazy and ill tell you it just doesnt feel right shimming them all different ways like that but im really gald that PITA is over.

Btw I tried an over head spring compressor very reluctantly and i now love that thing. Once I lubed up the points of movement it worked so well i couldnt believe it.

Reinstalled oil squirters with blue loctite. Got my crank/main clearances and they were all well below max of 4.6 thou. Crank spins smoothly by hand its all torqued.

Lots of work to do tomorrow.

You must be registered for see images attach

 

[The_Josh_Bear]

Nice work!

 

[saburai]

Looking good!

 

[MICHAEL MICHAUD]

Trying to check the clearances. Some of my lifters failed by crushing the washer in a slanted way so i have to improve those. Looks like the ones that stayed strong are showing some extremely tight clearances well below 15 thou. Time to try this a 3rd time with more consistent lifters.

Is there anychance I have the lifters too stiff up against the top clip. Does the lifter remain wholly stiff under operating conditions?

I might have to get my valves taken down. My clearance right now is like .004. I think something is fishy. Going to rebuild the lifters with larger diameter washers and try again. I think when the lifters cap canted the push rods rode the highest part conpressing the valves deeper than they would normally depress. But maybe they rode the shallow part... hmmm. Gotta get some consistency here

Torqing these heads 4x a night is not pleasant

You must be registered for see images attach

 

[IDIBRONCO]

Trying to check the clearances. Some of my lifters failed by crushing the washer in a slanted way so i have to improve those. Looks like the ones that stayed strong are showing some extremely tight clearances well below 15 thou. Time to try this a 3rd time with more consistent lifters.

Is there anychance I have the lifters too stiff up against the top clip. Does the lifter remain wholly stiff under operating conditions?

I might have to get my valves taken down. My clearance right now is like .004. I think something is fishy. Going to rebuild the lifters with larger diameter washers and try again.

Torqing these heads 4x a night is not pleasant

You must be registered for see images attach

This is why I used 3/16" washers and nothing else. They fit perfectly inside the lifter and I filled them up entirely. This way, there's nothing inside the lifter to cause issues like you're having. On one lifter, it was so tight that I had to actually tap the clip back into it's groove with a flat tip screwdriver and a hammer. TAP is the key word here. In my opinion, you want absolutly zero give ion the lifter in order to get the worst case possible with your valve clearances. Since our lifters are mostly hydraulic in operating the pushrods, I assume that there will always be a little bit of give, even with full, cold oil pressure. It may only be .001" or .002" though. I agree, tourquing the heads four times in one night would suck, but it's still better to know that everything's right before you install the engine.

 

[MICHAEL MICHAUD]

So i found the comp cams guide to checking valve clearance with hydraulic lifters and it requires you to make solid lifters and zero your valve lash. the reason my clearances were so small is because I haven't zeroed the lash for the test. I need to create an adjustable push-rod to check it more accurately. @typ4 made me aware of this and recommended the guide. Here it is for those who area interested. It doesnt even say to torque down the heads just subtract the difference between a torqued and a non torqued head gasket from the clearance you measure.

http://www.compcams.com/v002/Instructions/Files/145.pdf

I only took of 7 thou from each head. I lapped the valves and am using a 10 thou thicker head gasket. I dont have extra push-rods right now to make a custom adjustable threaded push rod so I haven't decided if I am just going to hope for the best and put it together or wait a month to pick back up on finishing this project. I think plenty of people are running typ4 and R&D cams without ever checking their valve clearances because they didnt pull the engine.

It does seem that the way im doing the test brings the piston and valve as close as they could ever reasonably be if the hydraulic lifters locked up and did not have any spring to them. The clearance is so small that i cant tell if the valves are actually just hitting, i mean the playdough is actually transparent it has been smushed so much.

EDIT: Repeated experiment. All of the intake valves are too close and 1 of the exhaust valves. 3 of the exhaust valves are good.

Heres whats happening though, without zeroing the valve lash with the solid lifters the valves are opening sooner than they normally would and staying open longer. When you zero the valve lash it gives you a true range of motion. Without zeroing it the pistons appear to actually hit the intake valves, crush the clay, , and force the spring to compress more so i dont actually feel the contact. Ill measure how much it is in the morning but it is extremely thin.

I need to zero the valve lash with a custom pushrod or forget about this test. Its also comcerning that bronco and wes perform this test the same way but get legit clearances. I measured my deck to deck height and its in limits so my heads havent been over surfaced. Frustrating but im not going down this easy.

If i make a custom push rod ill order some new ones and cut 1 inch or so off two of the old ones, thread both sides and connect them with a barrel nut so i can adjust the push rod height and do the test the correct way.

 

[IDIBRONCO]

Any idea how much the valves expand in length under high engine temps?

 

[MICHAEL MICHAUD]

Any idea how much the valves expand in length under high engine temps?

No sir. Id imagine some though. Im standing in the water on this build for the next month. Im not going to finish by Sunday. Just ran into some problems with the 2 of the nuts stripping out on the front plate. Abused from a previous water pump change.

I am going to look into getting some pushrods so I can make a few adjustable ones for when I can pick back up.

Should I tap those retained nuts onthe front plate with the next larger size and get some new bolts or cut the nuts off and weld new ones on?

 

[Thewespaul]

Using an online thermal expansion coefficient calculator, carbon based steel at that length would change .00000000125 meters in a 1200*F change

 

[Thewespaul]

No sir. Id imagine some though. Im standing in the water on this build for the next month. Im not going to finish by Sunday. Just ran into some problems with the 2 of the nuts stripping out on the front plate. Abused from a previous water pump change.

I am going to look into getting some pushrods so I can make a few adjustable ones for when I can pick back up.

Should I tap those retained nuts onthe front plate with the next larger size and get some new bolts or cut the nuts off and weld new ones on?

I got those pushrods in stock if you need them. Can you post a pic of the front cover hardware that’s stripped?


Edit. I see what you mean now about the nuts. You should be able to just replace them. Otherwise I’ve got spare covers too haha

 

[IDIBRONCO]

Using an online thermal expansion coefficient calculator, carbon based steel at that length would change .00000000125 meters in a 1200*F change

So , for all practical purposes, that's zero expansion. Thanks Wes!

I am going to look into getting some pushrods so I can make a few adjustable ones for when I can pick back up.

You can buy adjustable pushrods. I'd bet that Summit racing would have them, among others. Maybe these are the ones that Wes was talking about since he has a background in racing engines. Yes. I did forget to mention it in my last post. Also, the diameter of them doesn't matter since you're not going to actually run the engine with them installed. I say this because I believe that they are usually 5/16" and our are 3/8".

Should I tap those retained nuts onthe front plate with the next larger size and get some new bolts or cut the nuts off and weld new ones on?

Personally, I'd try the tap method first. Especially since you already have the cover off. A 3/8" bolt in the right length will be easy enough to find. You may have to drill the hole in the water pump out larger too.

 

[laserjock]

If you are using stainless steel valves, it’s probably less. I’m pretty sure stainless has a lower expansion coefficient.