86 piston in an 88 cylinder.

[number5]

I think I have a 86 bottom end. I diffently have a 86 piston and 88 cylinder. Why would someone use this combo? I noticed the cylinder sleeve is cracked on exhaust side. So I have to by a new sleeve and piston. Do I have a 86 crank because of no spacer plate?

[danbobsR]

you use a spacer plate if you have a 86 piston and a 88 crank the cylinders will interchange

[number5]

Oh ok so I can use any cylinder with the 86 crank. Its if I go the other way 86 cylinder and piston with 88,89 crank or is it 87,88,89 crank I would need a spacer plate. Thanks

[danbobsR]

87 88 89 are long rod cranks 85 86 is short rod. there is 5mm different from the 87 - 89 and the 85 86. so if you put a 89 crank with a 86 piston you gain 5mm in stroke that is why people do it. thus needing a spacer plate to make up the difference.

[number5]

Ok thank you very much. One more question. Do I have to use a 86 piston with my 88 cylinder? I have a 86 bottom end with 86 crank and piston. I noticed my sleeve is cracked and I need a new sleeve so I was wondering if I can get a different piston or do I need to get a 86 piston again.

[zedicus00]

86 bottom end you need an 86 piston. you can use any yr jug 85-89 on any yr bottom end.

if you hav an 85-86 rod (short rod) u need to use a 85 86 piston.

if you hav a long rod you CAN use an 85-86 piston by adding a spacer plate. this DOES NOT increase stroke. it does move everything up 5mm which adds a little crankcase volume.

the real reason peeple use the 85-86 piston on the longrod is because you can get it in larger sizes meaning you can bore yur jug more b4 resleeving it.

any more questions.?

[number5]

Wow thanks alot. I owned a banshee for years and didnt have a clue about the r. But I like it better. Ok one more question. Now that I have to resleeve my cylinder and I know what set up I have. what sleeve do I need to make it a 265? I just know that is popular with racing so I figured I need it for harescrambles.

[number5]

Also I went to wiseco website and seen they sell sleeves up to 88mm and sell pistons to 88.25 for the 87year to 89. I dont get it.

[zedicus00]

the later years have an intake bridge which is a good thing. you can put the later year sleave in an early model jug with no problem. a stock size sleeve can be bored to 265. are you sure you need to resleeve?

[number5]

There is a crack going across the bottom on exhaust side.

[DezSled]

LA Sleeve offers sleeves that are pressed in after the stock cylinder sleeve is bored out sufficently to accept the new one. It is an interference fit. The '85-6 piston pin heights are different from '87-9 piston. I was told that what ever year barrel/cylinder you use install that year piston, I have never had to do that so I'm not 100% sure if that is correct.
I would consult LA Sleeve before installing a '87-9 replacement sleeve into a '85-6 cylinder, as the bridged intake on the later year sleeve would be unsupported in the earlier cylinders.

[rockman]

What causes you to have the spacer is a difference in the piston not the cylinder.. I have the setup with 88 rod 86 piston with the 5mil spacer.

[number5]

I take it you choose the 86 piston so you can go bigger.

[rockman]

ya its bored .100 over