'88 GT Convertible - Croatia, Europe

snovak · Nov 15, 2021

I will be honest. Got it on first look. Damn. For the second time in a row I switched spark plug wires in hurry, #5 and #6 this time. Forget last post.

BUT this time it was not for nothing:
-#5 and #1 cylinders off (first journal) and knock is not audible (knew that from past tests)
- #5 and #6 switched by mistake, knocks only every few seconds...
Again, I am now almost positively sure that I will find something wrong with piston/cylinder #5.
As the engine keeps running strong, it may be a wrist pin as @General karthief suggested a while ago...

BTW Passed the inspection today, and I am road legal until 11/2022

Now I will slowly take everything apart again and pull the engine...
I won't be pulling the tranny so if there is a way to move it a bit back and avoid pumping that ATF out again, let me know....
For example: If I leave ATF in and disconnect cooling lines will I have leak from tranny or the line connectors are above liquid?

manicmechanic007 · Nov 15, 2021

It will leak some ATF down till the converter is half full and the pan is about full
Just cap the lines

WindsorPenchant · Dec 10, 2021

How's everything looking with this one..?

snovak · Dec 10, 2021

Howdy!

Lookin' fine, I just miss some time, approximately like additional 23 hours per day ;-)

Engine is on stand since Wednesday, but me...I'm on the trip to mountains with SWMBO and kids

I will keep You informed and documented as I tear down this 302, don't worry. It will be fun in garage, we are down to low 30 degrees this week...
Since last post I found some shiny particles (like aluminum dust) in oil behind oil pressure sensor, in that hex pipe.... We will see soon from where....
Compression test before pull shows lower values for #7 and #8. Cold engine, lower value dry, higher value with 5ml oil injected in cylinder.

AOD... Guys from first drop of tranny and now a second one... is it possible that ATF is not moving around? I started to think this since tranny cooling lines were almost empty this time...

P.S. This engine comes out piece of cake... so anyone hesistating - pull it out now!!!

snovak · Dec 16, 2021

General karthief said:
Wrist pin.

Yes :-(
More than two months ago, @General karthief you were absolutely right!

Heads are off and I have distinctive click on #5 downstroke....but still need to see if damage was done to piston itself or rod... goddamn strongest part in engine (pressed wrist pin) was damaged...

Furthermore:
- #5 has slight scratches and ridge from piston skirt I suppose, about 1" into the bore...
- #1 has scratches on three places.
We will need to bore the cylinders to 0.020".

Any recommendations for good quality/durable pistons and rings?

Edit: added some pictures

Noobz347 · Dec 16, 2021

snovak said:
Yes :-(
More than two months ago, @General karthief you were absolutely right!

Heads are off and I have distinctive click on #5 downstroke....but still need to see if damage was done to piston itself or rod... goddamn strongest part in engine (pressed wrist pin) was damaged...

Furthermore:
- #5 has slight scratches and ridge from piston skirt I suppose, about 1" into the bore...
- #1 has scratches on three places.
We will need to bore the cylinders to 0.020".

Any recommendations for good quality/durable pistons and rings?

Edit: added some pictures

No specific recommendations but you might steer clear of forged pistons unless you're planning boost.

General karthief · Dec 16, 2021

I can't recommend any specific brand, I'd look and see what rebuilders use like Jasper or Ford Performance on daily driver engines.
Mahle, wiseco are couple brands that have been around a minute

mikestang63 · Dec 17, 2021

snovak said:
Yes :-(
More than two months ago, @General karthief you were absolutely right!

Heads are off and I have distinctive click on #5 downstroke....but still need to see if damage was done to piston itself or rod... goddamn strongest part in engine (pressed wrist pin) was damaged...

Furthermore:
- #5 has slight scratches and ridge from piston skirt I suppose, about 1" into the bore...
- #1 has scratches on three places.
We will need to bore the cylinders to 0.020".

Any recommendations for good quality/durable pistons and rings?

Edit: added some pictures

i would go with whatever your engine builder or vendor you are sourcing your parts from is recommending to match with your build,. there are too many options. TRW, Mahle Total Seal are popular options

manicmechanic007 · Dec 17, 2021

Forged TRW or better
You only want to do this once
Speed pro combination cast iron and moly rings

Full float the pins and spiral locks

snovak · Dec 18, 2021

Thnx guys. @mikestang63 there is no builder, I am builder :-(

I found only these on summit:
https://www.summitracing.com/parts/slp-l2482f20 but ain't floating pins...
On rockauto I have Enginetech and Sealed power available...
BTW What is the stock CD on 88 GT? 1.605?
I see pistons from 1.585 to 1.619?

Worth to mention, after OEM bearings, I can tell that my engine was completely virgin, I was even the first with the heads off.
I will pull the crank out these days....

manicmechanic007 · Dec 18, 2021

Those should do nicely
The machine shop would have to full float the pins for you (hone the small end of the rods and cut circlip grooves in the pistons)
One of the advantages is that you can pull the piston off the rod yourself

Noobz347 · Dec 18, 2021

View: https://www.youtube.com/watch?v=rN2ND_FPnUA&ab_channel=driving4answers

Noobz347 · Dec 18, 2021

View: https://www.youtube.com/watch?v=GDMiKFrJmY4&ab_channel=driving4answers

snovak · Dec 19, 2021

Hmm, hey guys you are steering in different directions here

Based on video and reason for this rebuild I would take @Noobz347 advice and steer away from forged as I am sick of cold start (or any) tipe of knocks caused by piston slap. Also I don't plan to boost. This is a simple street and show car. Maybe some burnouts
@manicmechanic007 I don't like idea with messing around with new parts so I would opt for floating pins as supplied...
Stock are cast (?), therefore a hypereutectic should make a step ahead IMHO...

Based on upper parameters, would these fit on stock engine?

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Thnx!

snovak · Jan 11, 2022

Happy new 2022 champs!

Long time no report... I had family vacation in between tearing down engine... currently I have powerwashed block and I am scraping all the crap from block and heads to paint and protect them before machining.

This is what we've seen in the way to here:
- both new main and rod bearings have dirt wear marks (lines in motion direction), so we suppose it is due to dirty redneck bottom end rebuild/refresh (from underneath)
- block was all covered in thin layer of black oil residue (I am talking about inside), but oil passages are cleaner than I expected after peaking under lower intake for the first time and in bottom end (maybe seafoam did it's job)
- camshaft had slight marks you can barely feel with fingernail on two yournals, I hope I will manage to polish that out
- crankshaft has scored #1 main journal exactly in the area of oil hole
- combustion chambers were dirty as hell, but few valves I took out have nice shiny contact area, so they should be fine after cleaning and polishing
- piston #5 (the one that was knocking) has a to naked eye visible ring wear (piston ring gap is like 0.1") and cylinder wall is worn to side of outside wall. I suppose there was piston slap which may have escalated when I got the car... block was on the way to let the piston out for a walk - for sure....
- piston #1 (opposide than one that knocked) has three vertical lines in cylinder wall, and piston rings follow that "contour" and there are three embossed "nipples" following scratch marks. reason unknown.... only sign is more dirtier piston ring grooves than #5 for example

When I sum all the dirt I took out from the engine in last year, I suppose it was neglected for a long time, and I gave it too much TLC so maybe I disturbed some 30 years old crap which caused damage to #1 main journal and #1 piston wall.... allhtru #5 ring wear is still a bit unclear...

I gave all the external engine/accessories/bracket/intakes/timing cover.... etc... set of bolts a nice sandblasting and sparkling zinc coating. Yeah, a lot of labor, but got no propper imperial standard hardware store here to buy new bolts...
For the heads I have new ARP bolts, and crank/rod bolts I plan to re-use if it is suggestable?

Anyways, I hope that You will guide me so I will measure all cam and crank journals and report them here within today or next day,two. I still need to learn how to use subito bore measuring device so I can also measure cylinder walls.

Is it a smart move to give AOD to someone for rehaul? It is "working" but now I have it all apart and I can take AOD in my lap....

I am carefully listening to any suggestions....

manicmechanic007 · Jan 11, 2022

It depends on whether there is a trans rebuilder in your area who is worth a chit
Also the sea foam was not your problem but you will not see pros use it much just for the reason you describe
Use trans fluid instead and let time help
If it took 100 thousand miles to put the carbon and gunk in your engine
You really do not want to take it out in 5 minutes
So 1 quart trans fluid and the rest engine oil for 1 week then replace the oil filter
Inspect the oil and repeat a few times
Deburr the engine block and relieve the oil drain back passages then to machine shop
Paint the inside of the block with epoxy paint to aid oil drain back after you get it back from the machine shop
One thing at a time
Burn the trans up before getting it rebuilt

snovak · Jan 11, 2022

Thnx @manicmechanic007. There is tranny rebuilder which gives 2 years warranty but they want at least 2500usd for AOD rebuild....guess I will drive it until fails....

Oh, that seafoam was desperate measure when knock was already present back in September before dropping the pan.
Actually all oil drain passages were pretty clear, so I mentioned seafoam as a possible reason....

Guys, attached are all journals measures. Instrument was mitutoyo 0.001mm resolution, results are not rounded but I took 5-6 measurings and notes highest and lowest result. All journals are -0.0003-0.001" below tolerances.
Two questions:

1) This measures scream to mirror polish journals and use -0.001 main and rod bearings. Only concern is that first main has a little groove. So there is a risk.
2) Also there are no other than STD cam bearings...and two cam journals in middle have a small small groove. If I polish cam journals could I get away with it or I need a new camshaft?

Thnx and greetings guys!
Some pics of cleaning progress also ....

manicmechanic007 · Jan 11, 2022

Snovac,
If the block goes to the machine shop they will want to replace the cam bearings has always been my experience
Use a good inside mike (vernier dial caliper) to check the cam bearing installed size. Measure the cam bearings and journals individually
The cam bearings will loose all your oil pressure if they have too much clearance
How big a groove?
If you replace the cam bearings be sure to line up the oil feed holes

snovak · Jan 15, 2022

Hi!

Sorry, I had some health issues last couple of days... It's getting better now so I am returning to garage

@manicmechanic007 photos may show up worse or better than real thing, but this is as close as possible I got.
See, I got a first crank journal pic and third and fourth cam journals...
Is this camshaft saveable by polishing?

Also, guys does anybody know RAL code for OEM engine enamel from this period ('88)?

Thnx

90sickfox · Jan 15, 2022

Camshafts are so cheap here that I would just replace it. I don't know how expensive it would be for you over there.

'88 GT Convertible - Croatia, Europe

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Stangnet Facilities Maint Tech... Er... Janitor

wonder how much it would cost to ship you a pair

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Wasn't a pretty sight...and I've got big hands

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