Big Bore Kit, or not
- Martin Benade
- 356 Fan
- Posts: 12390
- Joined: Wed Nov 23, 2011 10:52 am
- Location: Cleveland, Ohio
Re: Big Bore Kit, or not
Make sure you shim both cylinders on a side the same so the head can seal. This is assuming the case and heads are in good shape.
Cleveland Ohio
62 Cabriolet
56 VW
02 IS 300
04 Sienna
62 Cabriolet
56 VW
02 IS 300
04 Sienna
- Ron LaDow
- 356 Fan
- Posts: 8095
- Joined: Wed Mar 26, 2008 11:45 am
- Location: San Francisco
Re: Big Bore Kit, or not
Wes, that thing was done in Works (I think) and I'd be surprised if it runs in the newer Works or Excel.Wes Bender wrote:Ron, I've got a copy of your C. R. spreadsheet on my computer, but is it available anywhere else? That's what I used when I did my latest rebuild and it works great.
I'll see if it's still on the older computer and see if I can get it on the web site.
Ron LaDow
www.precisionmatters.biz
www.precisionmatters.biz
- Peter Burger
- 356 Fan
- Posts: 79
- Joined: Sun Mar 28, 2010 7:24 pm
- Location: Spring, TX
Re: Big Bore Kit, or not
Ron, great write up once again. Very well explained.
It shows me once again: The more I know - the more I know what I do not know.
You say you do not like to use shims to adjust the compression. Do you always machine the parts?
I think I made up my mind and plan to use a new big bore kit
Norm, you said the Aluminum cylinder from AA won't fit. Can you explain? I would prefer the aluminum for better heat displacement.
I have the heads at 'Rennsport' in Sealy/Houston right now to have new valves and guides installed, so all should be good on that end soon. Maybe he can help me to determine the compression ratio. Without the proper tools - as offered by Ron - the only thing I can do in my shop is to measure the deck height.
Thanks everyone. I am learning little by little.
Peter
It shows me once again: The more I know - the more I know what I do not know.
You say you do not like to use shims to adjust the compression. Do you always machine the parts?
I think I made up my mind and plan to use a new big bore kit
Norm, you said the Aluminum cylinder from AA won't fit. Can you explain? I would prefer the aluminum for better heat displacement.
I have the heads at 'Rennsport' in Sealy/Houston right now to have new valves and guides installed, so all should be good on that end soon. Maybe he can help me to determine the compression ratio. Without the proper tools - as offered by Ron - the only thing I can do in my shop is to measure the deck height.
Thanks everyone. I am learning little by little.
Peter
'64 356C Coupe
'50 NSU Fox 98 Motorcycle
'51 Maico M126 Motorcycle
'51 Horex Regina 350 Motorcycle
'50 NSU Fox 98 Motorcycle
'51 Maico M126 Motorcycle
'51 Horex Regina 350 Motorcycle
- Ron LaDow
- 356 Fan
- Posts: 8095
- Joined: Wed Mar 26, 2008 11:45 am
- Location: San Francisco
Re: Big Bore Kit, or not
Yes. The chamber is where the power comes from, and I'll sacrifice much time to the gods of "quench". And several virgins, if I could find any...Peter Burger wrote:Ron, [...]
You say you do not like to use shims to adjust the compression. Do you always machine the parts?
Thanks for the kind words.
Ron LaDow
www.precisionmatters.biz
www.precisionmatters.biz
- Ron LaDow
- 356 Fan
- Posts: 8095
- Joined: Wed Mar 26, 2008 11:45 am
- Location: San Francisco
Re: Big Bore Kit, or not
Peter, make sure they cut the 30* conical surface to match the cylinder bore: Note that in this case, the edge of the conical section has not been matched to the cylinder bore diameter, which means the peripheral volume (Y) is now a "secondary" combustion chamber with the piston at TDC.Peter Burger wrote: I have the heads at 'Rennsport' in Sealy/Houston right now to have new valves and guides installed, so all should be good on that end soon.
Peter
I can guarantee the mixture trapped there will not burn with the mixture in the "primary" chamber, and while it's theorizing, I'd say it's a good guess you'd find a very high instant compression ratio in that "secondary" chamber leading to detonation and collapse of the ring land.
Pay attention to the chamber.
Ron LaDow
www.precisionmatters.biz
www.precisionmatters.biz
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- 356 Fan
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- Tag: Official curmudgeon
- Location: Ft Collins CO
Re: Big Bore Kit, or not
Peter,
I stated that the aluminum cylinders wouldn't fit.
That was 2 years ago and the problem was the al. fins were fat and distorted the head studs which
would have required a lot of machining.
It's likely this has been corrected or I got a bum set.
Norm
I stated that the aluminum cylinders wouldn't fit.
That was 2 years ago and the problem was the al. fins were fat and distorted the head studs which
would have required a lot of machining.
It's likely this has been corrected or I got a bum set.
Norm
- Peter Burger
- 356 Fan
- Posts: 79
- Joined: Sun Mar 28, 2010 7:24 pm
- Location: Spring, TX
Re: Big Bore Kit, or not
Ron, this is an interesting detail. Thanks for pointing this out.
Norm, thanks for the clarification.
I will let you guys know how things progress
Norm, thanks for the clarification.
I will let you guys know how things progress
'64 356C Coupe
'50 NSU Fox 98 Motorcycle
'51 Maico M126 Motorcycle
'51 Horex Regina 350 Motorcycle
'50 NSU Fox 98 Motorcycle
'51 Maico M126 Motorcycle
'51 Horex Regina 350 Motorcycle