I am looking ideally for a NOS +0.005 full skirt piston for a Mc 9 that I want to run with the stock manifold. I will take a larger one ( like +0.010 or 0.020 if I must). I have already contacted Terry Ives and he is looking for me too. I have cash or vintage items to trade. Thanks for the help.
Bob
Wanted a +0.005 or +0.010 Full skirt Piston for Mc9
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Bob Towarnicki
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Pruit Ginsberg
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Re: Wanted a +0.005 or +0.010 Full skirt Piston for Mc9
Hi Bob,
I could not find one in 020 for an MC 30 and eventually used a 91 piston. I hope 005 or 010 is easier to find. Contact Vince Hughes?
Pruit
I could not find one in 020 for an MC 30 and eventually used a 91 piston. I hope 005 or 010 is easier to find. Contact Vince Hughes?
Pruit
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Bob Towarnicki
- Posts: 122
- Joined: Sat Jun 16, 2007 5:45 pm
- Vintage Karting items owned: 65 Alley Kat Mc91
Narrow Hoop A Bone Mc91B
Various restoration projects - User Agreement: Yes
Re: Wanted a +0.005 or +0.010 Full skirt Piston for Mc9
Pruitt,
It has a +0.005 91 piston in it now but I want to take it back to its original configuration with the flat reeds, the third port functioning and a flatback and I learned the hardway that it won't run with the third port and a window piston. I think my friend Carl Haydt has solved my problem. He has a full skirt piston that is +0.010 so I will either have the piston turned down .005 and have new ring lands cut or bore the block out. That is unless a +0.005 turns up. I don't think Mac made a full skirt less than +0.010, it probably has to be Wiseco or another aftermarket brand.
Bob
It has a +0.005 91 piston in it now but I want to take it back to its original configuration with the flat reeds, the third port functioning and a flatback and I learned the hardway that it won't run with the third port and a window piston. I think my friend Carl Haydt has solved my problem. He has a full skirt piston that is +0.010 so I will either have the piston turned down .005 and have new ring lands cut or bore the block out. That is unless a +0.005 turns up. I don't think Mac made a full skirt less than +0.010, it probably has to be Wiseco or another aftermarket brand.
Bob
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steveohara
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1965 Dart Gran Prix twin Mc100s
1963 Bug Scorpion ESll Mc45
Re: Wanted a +0.005 or +0.010 Full skirt Piston for Mc9
Bob,
You may want to reconsider and stay with the 91 piston as there are certain benefits with respect to reliability over the original full skirt piston.
To use the original stock intake on a stock Mc9 block with a 91 piston all you need to do is make a gasket that blocks off the third port passage.
Closing off the "piston port" induction will not impair the performance as that system is there primarily to assist in starting when using a recoil and to improve idle.
Regarding the benefits of the 91 piston, the primary benefit is the substanstial improvement in lubrication and cooling of he wrist pin bearings. The original Mc 9 piston and all of the pistons with the closed end bearing on the exhaust side are much more prone to have bearing failure due to the lack of lubrication.
If you want to retain the original Mc 9 appearance and make small improvement in performance you can modify the stock 9 manifold like they did on the 45 and 75 so it will accept a pyramid reed cage and then you can remove the flat reed plate and you don't have to worry about blocking off the third port passage since the reed had been moved upstream in the system.
Regards,
Steve O'Hara
You may want to reconsider and stay with the 91 piston as there are certain benefits with respect to reliability over the original full skirt piston.
To use the original stock intake on a stock Mc9 block with a 91 piston all you need to do is make a gasket that blocks off the third port passage.
Closing off the "piston port" induction will not impair the performance as that system is there primarily to assist in starting when using a recoil and to improve idle.
Regarding the benefits of the 91 piston, the primary benefit is the substanstial improvement in lubrication and cooling of he wrist pin bearings. The original Mc 9 piston and all of the pistons with the closed end bearing on the exhaust side are much more prone to have bearing failure due to the lack of lubrication.
If you want to retain the original Mc 9 appearance and make small improvement in performance you can modify the stock 9 manifold like they did on the 45 and 75 so it will accept a pyramid reed cage and then you can remove the flat reed plate and you don't have to worry about blocking off the third port passage since the reed had been moved upstream in the system.
Regards,
Steve O'Hara
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Bob Towarnicki
- Posts: 122
- Joined: Sat Jun 16, 2007 5:45 pm
- Vintage Karting items owned: 65 Alley Kat Mc91
Narrow Hoop A Bone Mc91B
Various restoration projects - User Agreement: Yes
Re: Wanted a +0.005 or +0.010 Full skirt Piston for Mc9
Steve,
I thought about just blocking off the 3rd port with a gasket. When I rebuilt the engine I installed a Reed Sloper ala Mc90 and it ran fine. Then I wanted to take it back to stock to mate with another Mc9 I acquired to create my B Stock dual engine kart that I lusted for as a young teen. I installed the original manifold not realizing it wouldn't run that way. After that experience I remember there was a lot of conversation on this board about the issue with you and Ted contributing a lot to my knowledge. I like the idea of adapting the pyramid reeds. I think I will go that route.
Thanks,
Bob
I thought about just blocking off the 3rd port with a gasket. When I rebuilt the engine I installed a Reed Sloper ala Mc90 and it ran fine. Then I wanted to take it back to stock to mate with another Mc9 I acquired to create my B Stock dual engine kart that I lusted for as a young teen. I installed the original manifold not realizing it wouldn't run that way. After that experience I remember there was a lot of conversation on this board about the issue with you and Ted contributing a lot to my knowledge. I like the idea of adapting the pyramid reeds. I think I will go that route.
Thanks,
Bob