Rob Edwards

Some more progress this weekend, did a bunch more cleaning with Peter's (bmw635) help on Saturday:





I also started cleaning bits off the front of the engine, and pulled the TB and WP. The coolant passages are amazing for the miles:



Today the engine is apart as far as it's going to be, and everything is all cleaned up. Time to start putting things back together::






Driver's side valvetrain:




A little pitting on a few of the cam lobes, but otherwise not bad for 163K miles.



Bottom end and thrust bearing look good:



Front:


Rear:

AO

Hey Rob. Glad to see you following my advice to just pull the motor.

You can tell this motor was run with conventional motor oil. It never ceases to amaze me how sludgey/varnished they look. In the one pic of the cam lobe, it's almost impossible to tell the condition. Yuk! I'm sure you'll get it all nice and clean.

This is a nice winter project. Nothing major... just a nice clean up.

SteveG

Andrew, Now I'm curious what are you seeing that says "conventional oil" and I assume you mean 10W 40 dino?? Is it the dark areas on the lobes and what is that, varnish?

AO

Yep... that dino oil makes everything brown. Maybe that's not a bad thing, but when you open a motor that's been running full synthetic (my experience is limited to M1), the engine is clean as a whistle... on the inside.

Here's a pic of my engine with M1... see the difference?

Rob Edwards

This car has an interesting service history- there was a period when it got ridiculously short oil change intervals, which then spaced out later in its life. And the oils used were all over the place- Syntec, Mobil 1, 'synthetic' and just 'oil'....

For one brief 2300 mile stint in the winter of 1999, someone put ZVW 352 130 oil in it- 10W-30!


Here's the history by mileage and the service interval. About 1/2 were synthetic, and 1/2 not specified.

Of course, the last change got 2000 miles of use and then sat for 6 years. I sent some of the mid-drain oil to Blackstone- will put up the result when it comes back.

TexasDude74

I think the varnishing likely has more to do with drain interval than oil type.

SteveG

Re comparing dino and synthetic. The "brown" seems most notable in the bottom of the head, has a brown residue, which may actually just be oil and Andrew's has drained away and leaves no visible residue, could have just had more time to settle. I wonder about the dark coloration on the lobes and what that is evidence of. I bought a set of S3s for my GTS that have varying shades of that veneer. They look fine, but I don't really know how to judge them.

Rob Edwards

I think the flags need to go back on. Nice of Dan to keep the originals.

Mrmerlin

Glad this car got to you Rob its in great hands,
keep the progress pictures coming

mark kibort

well, if you used Wesson oil, that same result would occur. I think amsoil is nicer with that slightly redish hue left behind. and you wouldn't have those unsightly wear marks on the cams.

Rob Edwards

Another day or two of cleaning, got all the old parts cleaned up and stripped the old intake for its flappy guts, ISV, lower plenum, etc.

Was working on reassembling the valve covers and realized the old rubber plugs were still in the rear oil channels. They look ok but I have the pins and some loctite 574, so I pulled the rear cam bearings and R&R'ed everything









Man, the old intake was gross- I haven't seen one this bad:



The PC'ed intake is a bit better:



Decided to R&R the hood pad today, got most of the old pad off with a plastic scraper.



Residual adhesive softened and scraped with 3M 38984 adhesive remover:



Then the new pad installed with 3M #90 adhesive:



Prepped the cam gears for DFL-1, rebuilt the tensioner, R&R'ed the front crank seal, installed the new WP, etc. etc. Lots of little details. Hoping to have the motor back in by the end of the holidays. Then the interior work can begin....

The most corroded panel on the car is the fuel pump cover, so I decided to bead blast it in prep for a new coat of black:

Mark Anderson

Lots of impressive progress

worf928

So, you're swapping the original intake for one that's already powder coated? Isn't that akin to sacrilege on a GT motor since the intake is port-matched? (Or so legend would have us believe? Or was that only the '88SE & '89GT?)

Otherwise I agree with Mark:

Mark Anderson

I'm not sure Rob has owned a non GT engine between his GT, GTS, and GT motor he bought from me during our 1/2 off sale

Rob Edwards

Dave-

Interesting question, and I realized I have enough bits here to make a comparison:



There are two 4R intakes here, one from Mark's '91 GT, and one from the '91 S4 that I blew up in the Zombie back in January. The refinished intake is actually from an '89 that I got back in a batch of intakes that I had powdercoated for Greg.

I did a quick n dirty measurement across each runner's opening- turns out the 4R intake runners are ~2mm greater than the 2R runners at their greatest front-rear dimension:

All dimensions in mm:

Here's the measured dimension:



You can actually see the difference in the profile of the opening, relative to the injector hole. Same ports (#6 and 7, I think) on each intake

2R: Thicker 'shelf' between the port and the injector hole:




4R: Thinner 'shelf':



The other 4R:




So the immediate knee jerk is that I should get the original intake PC'ed (and I think I am going to drop it off in the morning, mostly since I think a '91 GT deserves a 4R intake. (The localt PC place has a pretty good turnaround time)

AND- it is also interesting to consider the fit of the intake gaskets- here is the gasket (oriented so the 'TOP' of the gasket is against the intake surface, and centered on the mounting studs, which dictate where the gasket sits..

Turns out (at least for this pair of Reinz gaskets) the overall fit is better matched to the 4R intake runners. The gasket was centered on the mounting holes around port #8 and then #7:

2R #8:




2R #7:


4R: #7:




And a low angle shot of the 4R intake/gasket fit on #7:



BUT: If you line up the gasket across all the runners, there are gaps and shoulders at random intervals around each runner. So I think that unless you're really lucky, the variation in the fit of the gasket to the runner is going to overwhelm some (all?) of the benefit of the bigger runners in the 4R intakes

Hmm, I wonder whether all engine builders go to the trouble of port-matching the gaskets between the intake and the heads? That would be a giant OCD PITA..