Story so far series 1 resto

[lancianut666]

Hi all
Did a bit of checking with the piston ring gauges we have and it seems that the rings are tight in the gauge but loose in the bore (68.4 mm)...The ring gap in the bore is outside the assembly setting but tight in the gauge indicating it would need a bit grinding off the end but that would make the gap even larger in the bore...I can't really measure the bores apart from at the top. At first glance it looks like the bores are too big. I will clean out the grooves and measure the groove gap against the piston ring next. The pictures show the difference visible to the eye.
Clarkey

[lancianut666]

Bit better news on the brakes...my son's had bought me a cordless dremmel gizmo so using a felt tip with some fine compound I cleaned up the crusty bores of the wheel cylinders and put it all back together and bled the brakes...no leaks yet!
Clarkey

[lancianut666]

Off to the machine shop tomorrow to see if we can get this engine sorted out. I have a spare block so if the original is goosed we can try the spare...

[lancianut666]

It is all very tight in there!

[lancianut666]

Visited the new machine shop where the bores were checked and to my surprise they were exactly as they should be at 68.4mm....However the machine shop man was not impressed with the piston rings describing them as having a finish like a 'Thruppennybit' so we concluded the rings were the problem. So we decided to have the bores honed a little bit and some new rings sourced and start all over again with the existing pistons as machine shop man declared them OK and good quality.
Clarkey

[lancianut666]

Hi all
A week of the Lurgy has hindered any progress till now but with the aid of my mate Terry we resumed the battle with the V4. The machine shop man took 'a couple of thou' off the crankshaft and we set too reassembling the engine. I was greatly relieved to get the crank in and find it now spun much more easily than the earlier attempt so far so good even with the bearing carriers tightened up.
...With the crank in we started fitting the pistons but the ring compressor was not up to the angle of the V and was letting the ring slip out before it entered the block so we resorted to squeezing the rings into the groove and gently tapping the piston in. After 3 pistons were in we only had to connect the con rod up to the crank for piston No1 and we were done...I said to Terry 'what is that bit of metal next to the piston?' Terry said 'looks like the tip off the screwdriver' but it wasn't was it...no it was a bit of piston ring.
Some how a bit had broken off and luckily for us had just dropped onto the surface of the block so I took the piston out and sure enough the second ring had a missing bit that matched our 'Lucky Find'
The good news was we had found this before we had put the engine back together so I was not too despondent (Terry was!) and I was really chuffed with the crankshaft as the 3 pistons would turn over by hand so easily compared to before. So before Terry went home we fitted the flywheel and bolted the half engine to the engine stand as it was starting to get a bit heavy and unwieldy.
The pictures show the crank and pistons after having a bath in my until now cleaner thing and a shot of the broken ring.
Clarkey

[Jaydub]

Hi Clarkey, When I rebuilt a Type 300 Mercedes engine, which has a much steeper angled blocked and a combustion chamber scalloped out on one side, it was a challenge to compress the rings. I found an oil filter canister of almost the same diameter as the piston, cut it open, cut one side shorter to accommodate the shape of the scallop on the opposite side, wrapped it around the piston and used a Jubilee clip to compress the rings. It worked a treat. Any can or piece of tin will do it. Might be worth a try.
Good Luck.

[lancialulu]

Dont want to say this but you may have damaged other rings on the other pistons by this makeshift assembly process. If you have no compressor it is just agony using finger tips and loads of oil but you feel the rings in not tap them....

[Jaydub]

Here is the ring clamp I made to fit this very unusual block/combustion chamber. You could something similar out of any correct /oversize can. Anything is better than your method which you have proved is bad practice, and has cost more time. No disrespect intended.

[lancianut666]

Hi all
Thanks for the wise words and advice...no progress since Friday as we have been visiting family and house hunting...also did myself a mischief as I sneezed and put my back out!!! so no cold draughty garages this week.
Clarkey

[lancianut666]

Will have a go over the next couple of days to get the engine back together as the purgatory of Xmas is upon us and Matron won't like me lurking in the garage on Xmas day.
Humbug Clarkey

[lancianut666]

Hi all
From a cold garage in North Yorkshire...replaced the broken ring and fitted the piston managed to squeeze the rings in by hand so no need for a custom made ring compressor. Glad to report crank and pistons turn over a lot more easily than last time so progress. We will see what tomorrow brings.
Clarkey

[lancianut666]

A picture tells a thousand words...

[lancianut666]

Had a slight hiccup putting the sump back on as one of the bolts sheared...a job for when the engine is all back together I think...

[lancianut666]

More death and destruction of 60+ year old Italian engine parts...When screwing one of the studs into the block I noticed it went in further than the others hmmm...anyway it locked into place so I got the head on and it was a fair few threads short where it poked through the head so I chanced my arm as they say and just used an ordinary nut without a washer. So far so good. Got the old torque wrenches out and set too following the pattern and settings as per the repair manual...We all know what happened next it tightened up a bit like all it's little friends but then decided it didn't like being part of this old engine and wanted to get out so it went slack and that was that. Question is dare I try to get the engine running and fix this later? or do I take the head off and helicoil it now? Problem is we might be moving house within a week or so and I will have to have the engine and gearbox back in the car to move it!!!! AGGGHHHHH!!!!
So to any one who has done the helicoil thing on an Appia block words of advice most appreciated. The culprit is stud no 6 all the others have tightened up to the correct torque with no problems. I'm guessing but the thread is M8 x 1.25
Sick as a chip from Scarborough