998 Automatic Engine Rebuild

He came this afternoon and picked up the block and says he'll have it back to me on Monday

 

Block came back this afternoon, and he had an interesting story to tell about what happened. I had the deck surfaced after he bored it and he said that distorted the cylinders slightly - they were out of round. He was able to clean them up with the rigid hone and only took about a half thou out to clean it up.

Now of course, I have to completely clean the block up again before I can assemble it....first scrub out the bores with a stiff bristle brush and solvent, then clean them with 409 on another clean brush, then with some penetrating oil, then with regular oil, each time wiping out with a clean white non-shedding cloth. If the white cloth comes out with no black on it - it's good to go.

 

Yeppers.....

If you've ever seen one of the surfacing machines, it has a large spinning head like a big dinner plate to which the cutter is attached - just the one - the head is large and very heavy so the cutter will cut and not set up a vibration as the wheel turns over it and cuts the deck.

My guess is that as it passes across the deck surface it slightly distorts the bores - makes them slightly out of round....especially at the top. At least that's how he explained it to me......

All I know is that when he brought it back the bores were nicely honed and the pistons seemed to fit perfectly.

Got the pistons and crank installed, now I'm working on setting the cam timing.

BTW, I don't reuse those nasty rusty screws or bolts, I replace them with new, usually grade 8 hardware, tho not everything requires that strength.

 

Got a little more done tonight.....

 

It's always sumthin..... things were moving along swimmingly till I noticed this......


I don't know how I didn't see it before but there it is. That black line is where the rear main seal rides, and it has worn thru the surface hardening of the gear. I've never seen one wear like this before - I've seen them wear a groove in but not this, where the surface is worn off like this.



And of course, 998 A+ (82-92) automatics are completely different from all the others!

I was able to find a new one at a specialty shop in England so it's on it's way to me, but will probably take 2 weeks to get here. Till then I can mount the engine on the gearbox and bolt the head on, but then I'm stuck till the gear gets here.

Click on the pics to see it up close....pretty gnarly, dude.

 

I made pretty significant progress today, it's mostly buttoned up, next job is to mount it to the transmission.....once I'm there I'm stuck till I get the new primary gear.

Head is on and torqued, valves have their preliminary adjustments. I do need to pop the top off the carb and clean it, it seems dirty inside, the dome probably has some dust or grit in it, and I need to change the needle to the right one for this cam, header and carb.

Edit: Yes I nipped up that hose clamp after I noticed it in the pic....

 

Got bored sitting around after my little hospital adventure (hard to believe it's only been a week!) so I bolted the engine to the transmission.....still have a few ends and odds to bolt up, new primary gear is supposed to be here Friday.

 

That was less than an hour of work, so no worries.....

And I'm done for today, tomorrow will be spent looking for the correct fasteners and laying them out, attaching a few more bits and bobs and so on.

Friday the primary gear is supposed to be here, so then I can add the rear cover, torque converter, oil pump and lines and so on, then it's about ready to go into the engine stand - that will be a red letter day!

I may have a buddy come over first and help me set it into the box again so I can make sure it will fit and look at how I'm going to brace it up.

Once it's in the engine stand I'll fire it up and run in the cam, once I get the timing set and all that, let it cool down overnight and retorque the head, reset the valves and fire it up one more time, then it's ready to go into the box and get shipped off. I'm going to have to check but I think my original estimate of time - given all that was going on - was back to him by the end of July - I'm right on pace to do that.

I may try and turn it over with my big ass 1/2" drill motor on the bench, otherwise it my have to crank an awful lot to fill the torque converter before it pressurizes the bearings.

 

Last thing I need is the gear that fits inside that black housing, then I can button it up and put it in the engine stand and make some noise! Still have to go thru the starter and alternator too, and install the dizzy and set the initial timing. So, plenty to do yet but it all hinges on getting that gear, it's supposed to be here today....

 

The new gear showed up today, so I got it cleaned up and installed on the crank and measured the clearance - it's spot on.



Then I covered the splines so they wouldn't damage the new seal and slid the rear cover on and bolted it all up....note where the dipstick is located.....there also is a nut at the bottom that I need to torque but I haven't figured out how to hold the shaft while I do that. Working on that idea.....I haven't even found a torque spec for it yet but it's either the same as that on the manual or just "gutenteit"!



Next up the torque converter goes on, but first I need to clean up and locktite the three bolts I took out so I could use the puller to get it off the crank taper.





Then I need to clean up and paint the starter and alternator, then install the dizzy and set the timing. With all that done it will be ready to fill the oil and see if I can crank up oil pressure. Before I do that I'm going to set it in the crate and evaluate where I need to put blocking to keep it from shifting in transit. I may build some simple braces out of EMT to keep it from toppling too.....

IF it fits in my engine stand, then next I'll see if it will run.......more as it happens!

 

Looks like my assumptions were correct, I did have to drill new holes in the mounts as it sits a little higher than a regular manual transmission engine does as the mounts are about 1/2 wider on an automatic subframe. No real matter as I just drilled 4 new holes and bolted it down. The engine steady will be a different matter tho, I will have to rework the engine end of the steady mount since I usually bolt onto the slave cylinder boss - and there is none......going to be an interesting challenge to figure this mount out.

I wound up taking the intake and exhaust header back off - I managed to get it in the engine stand with them on, but could not get them out again without scratching things, so I removed them.




Next up once I've got the engine stand mounts figured out, I'll pop it into the shipping box and see what I need to do there to secure it for the trip home. Then I can build all that stuff at once and have it ready to go.