88 thick wall cylinders

[m.abbadessa]

I have a 1600cc type 3 in a two seat Sandrail. Just did a leak down test and it returned 20% 42% 32% and 47% leak down. Tried to locate the leak and it seems to be coming from where the head meets the cylinder wall. The last time I put rings in it was approximately 10 years ago. I made sure the heads were torqued to spec. And the nuts did not even move. So I'm thinking its time for a tear down. I want to avoid splitting the case since nothing grenaded down low, but I do want more power. I saw some thick wall 88 cylinders online. I've been reading and hearing about staying away from thin walls. The ad states that the head must be machined for 90.5/92 and you leave the case the same at 85.5. What are your thoughts? Are these any good? Hoping I can get a little more power without splitting the case and having that machined also.

Thanks

[jpaull]

Its a GREAT way to go. Machine in 88's, refering to machining head side. 1679, beautifully 4.5mm thick, which is thicker then stock 85.5's even.


Thickness at the cylinder tops:

The new 92 mm from AA (4.55 mm)
Modern machine-in 88 mm (4.5 mm)
Stock 85.5 mm (4.15 mm)
Modern 90.5 mm (3.75 mm)
94s mm (3.55 mm)
87 mm slip-ins (3.4 mm)

Old 90.5 mm (3.25)
Old 92 mm (3.0 mm)
88 mm slip-ins (2.9 mm)
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[m.abbadessa]

Cool. That's what I was hoping to hear. Is the top part of the cylinder the important part since the bottom part that goes into the case will be thin?

[Danwvw]

I switched to the 88's Thin Bottom Thick top cylinders and have put them on 3 rebuilds now. The thing you got to watch with them is when you install the pistons. The metal is so thin at the bottom it split on me just slipping in the pistons with the rings on them, best to install them from the top but you can get away installing them from the bottom if very careful and don't bang on them using gentle force and don't use a Napa Chepo Ring Compressor. Use something like this one Ring Compressor.

Another thing that happened with the 88's is one set came to me that had not been properly clearanced where the fin's between the two cylinders come close when installed. It broke the fins and cracked the cylinders on mine.

Also I am getting some oil usage on one set About a 1/2 qrt every 600 miles. Not sure what is causing this it gets a lot worse on a long freeway run. 1/2 qrt per hour. But I think they are a good product once installed properly and working.

Broken installing rings from the bottom:

Don't use this type of ring compressor and don't use a rubber mallot:

Here is where the fins hit and that cracked the cylinders on 3 of them. Started the engine and the cylinders were leaking oil through the side of the cylinders after this happened.

These are the one's on my bus engine that is using oil:

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1960 Beetle And 1679cc DP W-100 & Dual Zeniths!

[m.abbadessa]

Thanks for the info. Is there a brand I should buy or a brand I should stay away from?

[Danwvw]

I think the only ones that are slip in at the case and thick walls are the AA Performance VW8800T1K set. There probably are some forged thick wall 88's machine in at the case that would be better but in other brands and much more expensive. But if your going to do that just go to the Mahle 90.5 Forged ones.
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1960 Beetle And 1679cc DP W-100 & Dual Zeniths!

[Bob Brugge]

I am in the process of building an 1849 cc w/ 88's and a 76mm crank. Haven't got it completed yet so I have no real good advice, but I will post here once I get it together and in.
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Keep on Dubbin'!

[Danwvw]

The 88's as the 85.5's and 87's are a little tricky to install on a stroked motor because the small piston diameter does not clear the rods. So you will be trimming your pistons a bit. With a 76mm stroke you may be better off going to 90.5 Pistons & Cylinders. It will be intresting to see how much trim they will need on a 76mm stroke.
These were trimmed for a 74mm stroke engine.

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1960 Beetle And 1679cc DP W-100 & Dual Zeniths!

[m.abbadessa]

Ok so I decided I'm going to go ahead and get the 88's. This is my first top end rebuild on a vw that isn't a stock 1600. I've spent the last couple days cleaning all the sand and grease off the outside of my heads. Now Is the next step is to get the heads machined for 88? Should I order my pistons and cylinders so I can take them with when I have the heads machined? Also are stock heads going to be ok with this engine size?
Thanks

[Cusser]

[[email protected]]

when you bore the heads (to 92mm register, for the 88mm TW P&Cs), that is the time to also flycut the heads (if needed) for the proper compression ratio for the cam you are going to run. Run the #s and see what head cc you need to get that CR, using a .055" deck height. Have the shop bore and flycut to that spec.

Also, I think trying to put the pistons on, then a compressor and sliding the cylinder on while on the engine, is the wrong way to do it. Simply put the piston into the cylinder on the bench, slide the piston up so the pin is exposed. Then RTV the cylinder base, and put the UNIT on. Put the pin and clip in place, and slide it home.

Do NOT make the rookie mistake of taking the new P&Cs, sliding the piston down enough to put the pin out/in, and assemble. You need to completely remove the piston to clean all the abrasive out of the piston and cylinder walls, it's extensive.
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[m.abbadessa]

Ok thanks. I have a stock cam in there as far as I know. What compression ratio should I set it at? I'm also contemplating putting some ratio rockers in. Which ones would you reccomend if I went this route? And is this something I can do later or should it be done while setting my conpression ratio?

[m.abbadessa]

[67jason]

[Floating VW]

[Alstrup]

[Floating VW]

That's a shame. Oh well, I treat these Brazilian jugs nice and they've done pretty well over the past eight years. I've got about 40K miles on them, and they still had less than 1% deviation on the compression test I did last summer. They were all bang on 155 psi.

The rings are Total Seal, though. Hopefully that'll make a difference.

P.S. Cryo treatment! Why didn't I think of that?!!
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