Finally starting a rebuild: Looong

[dtw]

This weekend I began the rebuild process on my 2.4 ex-T motor. Tim of Flying Turd fame joined in to supply an extra pair of hands. He also supplied a 2nd brain to review cleaning procedures and analyze the results of measurements and observations. The prep, measurement and cleaning takes hours. Actual assembly is straightforward, though it requires attention to detail and patience.

Plastigage is an effective tool. This was used to do a final evaluation of the rod bearing/rod journal clearances. 5 measured out at .04mm; 1 measured out at .06mm. Due to initial concerns over the additional clearance on #3 and a problem with particulate/dust getting into the orange goop (loctite case sealant), we elected to halt assembly procedures in order to take stock. (At that point, I wanted a few experienced opinions rendered on the “looser rod” - -it was noticeably easier to rotate that rod around the journal than the other 5, though all felt “good”).

Consultation on Pelican yielded: “check measurements and make sure they are in fact in spec, if one is slightly closer to the far end of the spec than the other 5, don't worry, bolt it up and run”. Consultation with my machine shop yielded the same advice.

I spent about 10 hours cleaning my case halves, so I was perturbed to see dust settling on the orange goop while in the middle of sealing up the case. The case assembly was halted and all the goop was carefully wiped up. Inspection of the left case half resulted in me noting some scale in the perimeter stud holes, even though I had cleaned out all loose soil. When I closed the case, the studs scraped this scale and dusted the mating surface. This was resolved by visiting a gun store and purchasing a few brass barrel brushes. Next weekend I’ll try again, my mechanic is obtaining a fresh pair of rod bolts and nuts for me. I hope to be timing cams next weekend!

Here’s a recap of what this engine is and what’s been done/replaced: this engine was a great runner and eventually torn down for a non-catastrophic bottom-end failure (rod bearing suspected of failure due to knocking noise; engine torn down by PO to confirm prior to massive failure) it is being reborn with 34mm intake ports, 2.2T pistons with additional valve clearancing machined in, heads shaved .004”, Crane 288 cams, and E MFI equipment. Anticipating excellent driveability with substantial improvement in top-end performance; we hope to dyno this motor in the future as it is a combination I haven’t seen before (especially the 288 cams).

The machining list: check/measure all major components.
-Replaced crank due to current crank being right on top of maximum specs on all journals.
-Oil bypass modification performed; replaced oil pump with appropriate unit.
-Main bearing bore “cleaned up” to within spec after noting .0005-.001” out of round conditions.
-Head studs time-serted.
-Honed and measured all iron cylinders and replaced out-of-round cylinders as necessary. -Replaced 2.4T pistons with 2.2T which were measured for all specs and relieved for hot cams and shaved heads.
-Heads shaved .004”; 29mm intake ports expanded to 34mm with intake/guide areas smoothed/detailed; triple angle valve job with new guides, seals, springs, etc. Valves measured and replaced as necessary

-New/upgraded parts list: all bearings (except #8), all gaskets/o-rings/seals, chains, ramps, layshaft sprockets, oil temp switch, oil return tubes, flywheel bolts, all perimeter, sump & valve cover hardware, updated oil bypass pistons, springs, caps, pressure-fed tensioners, updated idlers, and turbo cam line adapters, rings, rebuilt alternator, rebuilt starter, belts, engine mounts, plugs & wires (Bosch platinum & OEM Beru), ground straps, cap & “E” rotor, diz points eliminating box (Crane ignition), input shaft seal, pilot bearing, shift shaft seal, pressure plate, clutch, and probably lots of other stuff I’ve forgotten.

[Tim Walsh]

I'm pretty sure dave wanted this pic posted for this thread.

[Tim Walsh]

err let me try that again

[Jay Auskin]

Cool Dave. I'll be starting my rebuild soon. I just got my case and heads back from inspection/machining.

I'm going to be using 2.2T pistons also, but everything else will be rebuild to 2.4L T specs. Good luck with the rest of the rebuild!

[ChrisBennet]

Careful with those brass gun brushes. The bristles tend to break off. The stiff plastic or stainless steel ones tend to be more durable in my experience.
-Chris

[Tim Walsh]

Chris,
We didn't have any problems with the brass brush but this may be because the brushes were brand new and weren't fatiged at all.

[ChrisBennet]

BTW: That brush idea is a good one.
-Chris