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Re: Best way to fit 1000cc Nicasil to early R90/6 cases?
Posted: Thu Sep 30, 2010 8:48 pm
by gspd
mattcfish wrote:
What I meant was, to punch out the iron liner and replace it with an alloy sleave for 900 and lower cc models.
On another subject, I talked to Siebenrock about there 1070cc kits without a foot to fit inside the block. Apparently they used to put dowels on the the lower studs for alignment but found it unnecessary. It makes me wonder if you couldn't just cut/mill the foot off of regular 1000cc Nikasil jugs and bolt them onto an early block with 97mm spigots. How far would the piston skirt extend into the block? Would that be an issue? It seems like it would actually help with lower skirt lubrication.
Much simpler than stripping down the block and boring out the spigots to 99mm.
I think you can only do that if you use shorter skirt pistons.
Re: Best way to fit 1000cc Nicasil to early R90/6 cases?
Posted: Thu Sep 30, 2010 9:07 pm
by robtg
gspd wrote:mattcfish wrote:
What I meant was, to punch out the iron liner and replace it with an alloy sleave for 900 and lower cc models.
On another subject, I talked to Siebenrock about there 1070cc kits without a foot to fit inside the block. Apparently they used to put dowels on the the lower studs for alignment but found it unnecessary. It makes me wonder if you couldn't just cut/mill the foot off of regular 1000cc Nikasil jugs and bolt them onto an early block with 97mm spigots. How far would the piston skirt extend into the block? Would that be an issue? It seems like it would actually help with lower skirt lubrication.
Much simpler than stripping down the block and boring out the spigots to 99mm.
I think you can only do that if you use shorter skirt pistons.
Also, I believe they use a longer con rod in the kit. That would put the side thrust of the piston skirt higher in the bore
allowing a short or no spigot.
Re: Best way to fit 1000cc Nicasil to early R90/6 cases?
Posted: Thu Sep 30, 2010 11:53 pm
by mattcfish
robtg wrote:gspd wrote:mattcfish wrote:
What I meant was, to punch out the iron liner and replace it with an alloy sleave for 900 and lower cc models.
On another subject, I talked to Siebenrock about there 1070cc kits without a foot to fit inside the block. Apparently they used to put dowels on the the lower studs for alignment but found it unnecessary. It makes me wonder if you couldn't just cut/mill the foot off of regular 1000cc Nikasil jugs and bolt them onto an early block with 97mm spigots. How far would the piston skirt extend into the block? Would that be an issue? It seems like it would actually help with lower skirt lubrication.
Much simpler than stripping down the block and boring out the spigots to 99mm.
I think you can only do that if you use shorter skirt pistons.
Also, I believe they use a longer con rod in the kit. That would put the side thrust of the piston skirt higher in the bore
allowing a short or no spigot.
I know they use longer rods and short pistons. I'm just curious about how far the OEM skirts intrude into the block at the bottom of the stroke. I don't have a torn down motor in front of me, but I seem to remember that it wasn't very far. The OEM pistons have extra long skirts as it is compared to today's pistons. I'm curious if a little bit of skirt moving past the barrel would really cause any problem. The other solution would be to have some custom pistons made that would have a higher pin location and short skirt.
Re: Best way to fit 1000cc Nicasil to early R90/6 cases?
Posted: Fri Oct 01, 2010 12:05 am
by Max Headroom
mattcfish wrote:I'm curious if a little bit of skirt moving past the barrel would really cause any problem.
The piston skirt travels past the bottom of the cylinder wall on many engine designs. Nothing unusual.
Re: Best way to fit 1000cc Nicasil to early R90/6 cases?
Posted: Sat Oct 02, 2010 9:38 pm
by George Ryals
If you have a higher pin location, then you either have to have longer rods or shorten the cylinders the same amount you raise the pins.
Re: Best way to fit 1000cc Nicasil to early R90/6 cases?
Posted: Sun Oct 03, 2010 5:41 pm
by Major Softie
George Ryals wrote:If you have a higher pin location, then you either have to have longer rods or shorten the cylinders the same amount you raise the pins.
Well, you don't
have to. You might just enjoy a 5:1 CR.
Re: Best way to fit 1000cc Nicasil to early R90/6 cases?
Posted: Sun Oct 03, 2010 6:55 pm
by mattcfish
George Ryals wrote:If you have a higher pin location, then you either have to have longer rods or shorten the cylinders the same amount you raise the pins.
Obviously.. That's another discussion. I wonder if there are any OEM con rods out there (BMW, Mercedes, VW etc.) that would fit that bill.