Flex hone size.

[mxracer]

I'm going to be pulling my top end down on my engine to deglaze the cylinders and re-ring. (It's a new engine that I think has a ring seat issue)

Having 90.5mm P&C I wanted to make sure the reccomendation of using the 95mm vs the 89mm hone is the right choice? Also I plan on Deves or Grant rings, would 240 or 280 grit be right?

Thanks

[baked beetle]

I would probably go 320 and order a hone that is close to cylinder diameter, they are a bit oversized and with that size - less than 4" bore. 6-800 rpm max
_________________
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[67Beetle2017]

The slight oversize will not hurt the performance of the flexhone. That said the 95mm hone will be fine for 90.5mm cylinders.

Use a 280-400grit sillicon carbide for cast iron rings.

Personally, For 90-92mm VW pistons with cast iron cylinders and rings:
I use a 95mm 280Gr Silicon Carbide for cast iron Deves rings.

[Moz'z58]

Hello-

I'm doing the same thing now on a 1.7L and need some advice. Need to save $$ as best I can so a machine shop hone would be nice to skip. I have a new Lisle 'Glaze Breaker' w/ 220x stones - are these stones correct/adequate for new OEM Mahle ring set? Or should I get other stones?

Lisle shows #23530 'Hard Stones', and #23540 'Fine' 320x available for this #23500 hone tool.

Have 2 sets P/C's Berg TW 88's w/ 35k miles on each set, and will buy rings from them.

Any comments on using the old rings after a light glaze break only? - which are in good shape still, engine was well maintained and run cool. Save the new ring sets for future shop done Sunnen hone @ 70k? Just trying to get max utility in this new 'economy'

[67Beetle2017]

[mark tucker]

check the gap, check each ring,no way for us to tell if there any good to be re used,why for the "deglaze" is there a ring problem?and if the cylinders are not straight the ball hone will do nothing for it..

[Moz'z58]

Thanks for the comments. Here's my current dilemma/situation and experience. This engine is a Berg complete kit I bought in '88 and now has about 76k all in my '65 bus. Berg has been very good over the years and I would & have sent stuff to them for work -flywheel surface and new ring gear on a second VW, and have bought near all my parts from them. But I am in a bit of a time crunch now as urgent family situations req'r a trip to SoCal asap and this is my DD'r again now - for better or worse...I may be one of the last hold outs :/ ...surely their are a few others here

The eng history is one V/J @35k at which time I also bought the second 88 P/C set from Berg -'93 or so - and drove it touring and local as a second car only. But becoming again due to necessity my DD'r this past June, I disassembled and cleaned/checked and found nothing really amiss needing shop work per se. Did split the case and looked and plasti-gauged - kept all bearings in play as still very good, rods etc fine. Lapped in new valves as seats were still good from 35k V/J-good enough for now as I am not driving high mileages currently. It runs great and is strong , pulls grades well. But due low cash flow needed to keep it simple, otherwise I would have done new P/C's, and full V'J and guides, crank, rod brngs @ min.

I didn't know about the glaze-break recommendation. I re-installed the original P/C set that came w/ kit - balanced w/ all in the kit package - 35k seems not much miles in the context. Same P in each C and rings ditto - all same locations.

It fouled all 4 plugs w/in 200mi or so - but that was casual local driving - never any hard hot long period road miles. Blue/white smoke. Down on oil way way too soon. Then I tried hard driving it on some trusted advice to see if they would re-seat and I get lucky. #'s 1.2.&4 did reseat and plugs are perfect there, but #3 remains-maybe a tad better, and still some smoke, but much less.

So it needs to come out and be turned around asap. Have spoken Tim @ Berg and as always very helpful. My preference is to buy ring sets & misc'y from them, Flex-hone lightly the second set to avoid the time delay of a ship to&fro.

Can send the original balanced set to them later for the ideal rework. Today having a good set of DP heads rebored from stock 85.5 also at a very good shop w/ much VW aficionado experience. I just always sent/bought from Berg over the years, but now ship costs and time delays are making local work attractive if possible. A local big shop w/Sunnen etc etc has been very expensive for VW A/C in the past as they mostly do American v8 stuff - another reason I went Berg in preferrence. But their prices are now competitive as they need the work - they just weren't interested before.

So that's my connundrum here. Tim may be able to point me in the right direction regards a home hone/hatch angle/grits/plateaus(oh brother ) - doubtful actually and I'd pefer not to bug him with shade-tree ?'s. Another local here too who will know, but haven't bother him with this ? yet. I'd just buy another set in the past and avoid this but prices have doubled, and the time thing if I can avoid it is a major factor.