88mm B&P

Is anybody running 88mm barrels & pistons ?If so what do you think or has anybody got some info.:P

Kafer

U talkin machine in or slip in??

I saw Mick was selling thisk walled 88's on his parts list.
Didnt think they were available.
Great for a bus!!.

Beetle - why no go 90.5's or 94's

Slip ins - dont even ask the question!

these are mick's and I'm not sure about slip or machine what's the diff.?

Slip ins are where the 88mm piston has the same outside diameter as 85.5's (stock)
The first "slip in" is 87's. This gives you a 1641cc - 57cc more than a stock 1600 (1584cc) They do this by "thinning" the walls. Then came the "infamous" 88's. This gives you 1679cc.

The "benefit" is you dont have to split the case to nachine it.
The "detrimit" is they are so thin they twist , warp, cut into the sealing edge of your head, end up wife blow by and generally all round stink!.

A machine in is where you have to split the case and and cut bigger piston holes.

SO why not just cut for 90.5's or 94's.
Berg (who?) made 88's famous back in the 70's with his motors. They didnt have 94's then and 90.5's were rare. Hell the 1500 (83mm's) had only just come ouut.

A machine in cylinder has really thick walls and will take a lot of abuse. Bus peolpe really like them cause of the heavy weight they have to push

BBK 198 088 BIG BORE KIT WIDE WALL 88mm

this is them - IF they are them, then they are the good ones.

Just for the work your better going at least the exta 100cc for a 1775

I've got a case machined for 94's but it's a 1300 case with small oil galleries. Don't think i'll use it. Keep it for a rainy day. Mick's selling the 88's for a third of the cost of the 94's . I'm thinking of a turbo or blower so am thinking the 88's will be a better proposition down the track. I'm pretty sure the 88's are machine in and were meant for aircraft use.

ok - that makes sense. Aircraft use.
IF you are going turbo then that could be a good choice.

With your 1300 case i thought there was a post a bit back that said 1300 cases were a good choice..

I'll try and find the post. However with a bigger oil pump required I would have thought bigger oil galleries would be an advantage. Pressure drop across an oriface and all that. If you know the post in question let me.

what these 88's gonna set ya back?
cheers
rhys

Not to mention duel reliefs

Rhys price I was quoted was $220 bargain I think. Ring Mick to confirm But please leave some for me.
Blue, info on 1300 cases was for duel relief 1300 case not single relief.

Blue's post said they were "wide wall" 88s. That means they are machine-in and won't warp.

$220 sounds good compared to the cost of 90.5s etc, though of course the capacity is less.

The 1300 dual relief case meantioned in this thread should be a good one for upgrading - as a 1300 is would have had an easier workout in it's earlier life and so should be in good condition (other things being equal) compared to a similar 1600 case (the 1300 and 1600 case holes are exactly the same - the 1300 P&C just have very thick walls).

hey kafer
im gonna find some carby's first!!!
cheers
rhys
p.s. then ill really try out my ported and polished heads!

Beg to differ, aussiebug - I believe the 1300s had the same wall-thickness as the 1600s, except at the spigot and head areas. The "thin-wall" "thick-wall" argument traditionally refers to the early aftermarket 88&92mm kits, which continued the problem throughout the barrel. I'm not so sure the dodgy versions are still made (most P&Cs come from two factories these days, both from the same company.)

70AutoStik wrote:Beg to differ, aussiebug - I believe the 1300s had the same wall-thickness as the 1600s, except at the spigot and head areas. The "thin-wall" "thick-wall" argument traditionally refers to the early aftermarket 88&92mm kits, which continued the problem throughout the barrel. I'm not so sure the dodgy versions are still made (most P&Cs come from two factories these days, both from the same company.)

The 1300, 1500 and 1600 P&C use the same sized hole in the case - you can remove a set of 1300 clyinders and slip in the 1600 cylinders without altering the case.

Yes - there are differences in the heads, and the combustion chamber volume is different of course, using 1300 heads on a 1600 would provide 8.8:1 compression and 1500 heads provide 8:1 compression.

Just for info, I converted my 1500 to a 1600sp and still have the original unmodified 1500 heads on it.

The "thin wall" argument applies to 87mm (1641), 88 slip in (1679) and 92 mm (1835) cylinders.

There are also 88mm machine in cylinders which the thicker walls. (Though if you have to machine the case, why not go to 90.5 cylinders at least - 88s provide only a maginal increase in performance).

90.5s (1776) are machine in, and the same hole size can then be used for the thinner walled 92s.

94mm are machine in.

So in effect you have four case hole sizes in that mix - suitable for 85.5, 88 (machine in), 92 and 94, with the in between sizes having the thinner walls.

Both thin walled and thick walled 88s are still offered for sale - for example this page advertises both the 87 and 88s "without machining"
http://www.jcwhitney.com/product.jhtml?CATID=36192&BQ=jcw2
(Not that jcwhitney is recommended - most US folks in the know don't buy much VW stuff from them.)