Hello! I am writing from Spain. Sorry if I write wrong. And sorry for putting units in metric system.

Here it is very difficult to find certain pieces but it is still more difficult to find information or a mechanic who can guide me.

I have been lucky enough to find a pair of unused STD Shovelution heads. They are EVO cylinder heads with the Shovel bolt pattern.

As many of you know, to mount those cylinder heads on Shovel cylinders, you have to eliminate the upper lip of the sleeve that appears, because the cylinder heads are flat like those of EVO, and add at the base of the cylinders stroke plates to keep the race enough, and then use EVO flat top pistons.

I had an idea, but when I ask, they simply say "it does not work" but they do not give me any explanation.

S & S has 3-1/2 pistons for stroker crankshaft 4-5/8 89ci) which are approximately 4.75mm shorter (106-5554 piston kit). Approximately the same length of sleeve that I have to remove. And I thought I could use those pistons and do without the stroke plates.

I attach a drawing and the data of the pistons.

Do you think it can work? Do you know if these pistons weigh the same as the original ones? Or should I rebalance the flywheel?
And if it can not work, can you explain me why?

thank you very very much!!

 

use the S&S stroker pistons,(we always used 30* pistons & machined the heads to 30*,then machined the dome to get the compression desired) but the S&S pistons will work.they will be close enough in weight not to require re balance

 

Thank you for the info!

I want to try the better squish of the shovelution heads with flat top pistons.

When i finished, i add some pics in this post.

Thanks.

 

Subscribed... Very interested in completion...

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For the moment, i have the build process of the bottom end in Instagram: Ros Ysumenteinquieta.

Right Panhead 61' case, left Shovel 71' alternator case. 4-1/4 flywhell..... And 80' EVO oil pump conversion....

Thanks!!

 

Because of the different year cases etc. etc. I would run this thread over in the Shovelhead section. Probably get a lot more attention..

 

Ok, i go to open a new thread in Shovelhead section with some pics.

Thanks!!

 

you get a much better squish band with 20* or 30* pistons when set up right

 

This is the combustion chamber of Shovelution Heads. ARe improved to use EVO flat top pistons.



I would like to use flat top pistons, it was the purpose of this improvement of a top end Shovel