Liner Seals

[Ron]

$.01

If you get close to the same measurements with the digital mic as you did with the feelers, I.E., Barely within tolerances, you'll have the dealers Et. al. and the measurements saying to use the largest...

Do it!

...But don't blame me.

P.S. To eases your mind, consider that the seals only have to hold off ~1/10 of the pressure the head gaskets do, before the explosion...

[Parzival]

ok, so got a dial gage, and here are the results.

Cylinders
1 valley side: .007 Outside .007
2 valley side: .007 Outside .0065
3 valley side: .007 Outside .007
4 valley side: .007 Outside .007
5 valley side: .008 Outside .008
6 valley side: .007 Outside .007
IMG_5106.jpg
compatible results to the feeler gages

[Bitsyncmaster]

Thanks. Right the IAC does not seal shut. But mine is sticking too far open in closed loop, I would think the difference in how far it closes at 1500 and 750 Rpm is not a lot. When I tap on it it does close a little further and drops the rpm to about a 1100.
Idle does not hunt or surge. FV duty cycle percentage is way high in closed Loop which tells me the Lambda system is working, just need less air to bring that down. I will post the fix. But so far Fuel Pressure is good Timing is right No external vac leaks.
It does rev good so mixture is close but not right yet WOT switch works. coming up on days off again so should get another look at it soon.

+1

Another problem is when your deceleration valves are bad. That extra vacuum leak makes the Idle motor run to it's minimum opening. The idle motor has very little torque at the extreme ends and any sticking will most likely happen then. When I designed my idle ECU I noted the best torque at the center value (FV duty cycle at 50%). What I did to get a little better was to reduce the frequency of the motor control from 100 Hz. to 66 Hz.

[Parzival]

ok, so got a dial gage, and here are the results.

Cylinders
1 valley side: .007 Outside .007
2 valley side: .007 Outside .0065
3 valley side: .007 Outside .007
4 valley side: .007 Outside .007
5 valley side: .008 Outside .008
6 valley side: .007 Outside .007
IMG_5106.jpg
compatible results to the feeler gages

Ok so, any input on these measurements?
They seem to be with in spec, but cylinder 5 is a bit higher then the ones on ether side of it. Should I put the next size shim in that spot, or move that liner to ether 4 or 6. Can I even do that since I'm keeping the rods and pistons in the liners, meaning I'd have to swap the whole assembly with one of its neighbors. The book says then need to be within .001 of each other which I appear to be. Since they are so close should I leave the shims dry or rub some hylomar on them? so many questions!!!

[dmc4087]

Following this thread as I'm in the same boat - regarding the liners, DMCMW Dave said they go on dry so you can rule out hylomar. One less question

Ref:
http://dmctalk.org/showthread.php?66...ve-moved/page3

[Delorean Industries]

The paper shims do need to be dressed in Hylomar AF. Anyone that tells you otherwise doesn't know what they are doing.

[dmc4087]

OP, add that question back on to the list

[Parzival]

OP, add that question back on to the list

Ok well, I know hylomar is good stuff, I don’t think it won’t hurt to add it, Belt and suspenders I guess.


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[Parzival]

Ok well, I know hylomar is good stuff, I don’t think it won’t hurt to add it, Belt and suspenders I guess.


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I meant I dont think it will hurt to add it, I guess I'll dress them gaskets up and put it back toghether. Liner measurements seem to be in spec.

[David T]

If you use an ordinary paper or metal shim you should use some kind of sealer. The type of shim the manual says to use would not need any additional sealer. Not sure what the availability is of those shims anymore. Important to use a sealer meant for this application if you do use a sealer. Lotus had a big problem with liner seal sealer in their early V-8's and it resulted in a recall. The sealer must remain somewhat flexible. If it hardens it cracks. Even though the liner is locked in place by the step in the block and the clamping pressure of the heads, it still moves slightly. The sealer must be flexible to accommodate that movement and the thermal variations along with the different expansion and contraction rates of the steel liners and the aluminum block. Some sealer require a primer. Some have very specific times that it can be assembled in before it dries out. Important details. In all cases all of the sealing surfaces must be scrupulously clean.