Retitled: Gypsie's rebuild

chitwnvw · Post by **chitwnvw** » Thu Jun 30, 2011 11:43 am

hambone wrote:Yep. Under a socket extension.

It would probably be acceptable to use them to check end play as well, no?

Bleyseng · Post by **Bleyseng** » Thu Jun 30, 2011 1:09 pm

pretty easy to do with a dial indicator and way more accurate.

chitwnvw · Post by **chitwnvw** » Thu Jun 30, 2011 1:20 pm

Bleyseng wrote:pretty easy to do with a dial indicator and way more accurate.

If only I had one...

hambone · Post by **hambone** » Thu Jun 30, 2011 3:05 pm

Got mine at Harbor Freight, seems pretty accurate. Yeah yeah.

Bleyseng · Post by **Bleyseng** » Thu Jun 30, 2011 5:15 pm

yep, only $14.95 at HB...great tool for lots of measuring.

Gypsie · Post by **Gypsie** » Fri Jul 01, 2011 10:24 am

Wow...I have been in this part of the wilderness before...And forgot...

viewtopic.php?f=46&t=1257

Many opinions and thoughts for this cat skinnin'....
http://forums.aircooledtechnology.com/s ... d.php?t=41

hambone · Post by **hambone** » Fri Jul 01, 2011 9:05 pm

Drug addled brain.....
and then there's you.

Gypsie · Post by **Gypsie** » Tue Jul 05, 2011 9:10 am

Please let this be close to the end...

I have reassembled the engine and it is installed. I haven't fired it up yet because I finished up last night just before Fireworks and I want to be rested and ready for the moment of truth.

It is on the charger and I will try this evening.

In the end I made several discoveries that were, I believe, the main culprits for my recent low end sluggishness and the generally low compression, and head leak in the #3.)

First off I will acknowledge my own stupidity for not fully groking the Deck height/ compression ratio, chamber volume CC's interplay. I steamed forward with bad math and an incomplete view of the variables.

When I did my calculations for CR I had not included the dish portion of the piston. Mine measured out to 14 cc's. (added to the 56 cc's of cyoinder head came out to 70cc's) But read on for more intrigue...

Deck height (after removing the thick base rings I had erroneously installed was .025" for all 4 cylinders).

The 'step cut' (that is kind of a pseudo "head gasket") in my cylinder head was .030", (which calcs out to 6 cc's) These additional CC's are best removed (70cc's - 6 cc's leaves 64 cc's)) and added back in the form of DH (.030" + . 025"= .055" or "in the zone".
Stroke measured out to 71 and bore is known at 94

I have been coached that the step cut is best added as a DH variable rather than a CC variable though either way the CR comes out pretty close to the same.

This puts me at 7.7:1 CR. A tad more than stock. I have also been coached that I could come up even more though that would require having some machine work done and I am Standing pat on that for now.

The other issue I discovered, and will redfacedly share with you here, is why I believe my #3 cylinder was leaking. Disassembly did reveal a blowby condition. A "general area blowby" and not a tiny localized type. During this disassambly I pulled apart P&C's to inspect the new rings and barrel to make sure that they seated well and had not become lined up. They had seated well and not lined up. ??? Well, think I, just clean it up, and put them back together. During the clean up of the #4 barrel I noticed that the base metal looked a little different than the other barrels. Closer inspection and solvent scrubbing revealed the .010" shim that had been left on from the first installation.... ?!?!?
The #4 cylinder had .010' extra lift on the barrel. This is what caused my blowby, IMO.

Now to hope that my new holes in the throttle plate will not give me too much trouble. I have already tested fitment of a 1/8" rivet and will be able to do it with the valve body in place if needed.

Too much time between processes during that last R&R session, which made me overlook several things (remember that half set of cam bearings I found on the bench?)...

I am hopeful for this to be a few adjustments for dialing in and calling it good.

Now I am looking forward to my visit with Colin where I hope we can focus on front end/brakes stuff.

Fingers crossed...

hambone · Post by **hambone** » Tue Jul 05, 2011 10:40 am

Good luck. Those damn AMC heads make me nervous!!!

tristessa · Post by **tristessa** » Tue Jul 05, 2011 12:21 pm

hambone wrote:Those damn AMC heads make me nervous!!!

.. bad experience in a Pacer?

chachi · Post by **chachi** » Tue Jul 05, 2011 2:13 pm

Gypsie · Post by **Gypsie** » Tue Jul 05, 2011 4:31 pm

Don't get me stahted....

bajaman72 · Post by **bajaman72** » Tue Jul 05, 2011 5:56 pm

I'm gettin excited for the start up.

LiveonJG · Post by **LiveonJG** » Tue Jul 05, 2011 9:31 pm

bajaman72 wrote:I'm gettin excited for the start up.

As we all are.

Postive thoughts are heading north...

ruckman101 · Post by **ruckman101** » Tue Jul 05, 2011 11:46 pm

I will interpret the fact that I did not hear a long, loud wail of dismay up here in Amboy this evening as a positive sign. Fingers crossed.

neal

Itinerant Air-Cooled

Itinerant Air-Cooled

Retitled: Gypsie's rebuild

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