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So what does that give me for displacement and what does this give me for cam options? I did double check the 4-3/4 stroke as well. Ill have to get a closer picture of the springs.
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Last edited by drohagan; 03-25-2020, 7:31 PM. -
Also looks like the old TRW pistons ...
Been a few years since those have been around. Think S&S went to Wisceos about 2004 ..
Cubes are at 89.12 inches ..Last edited by Dragstews; 03-25-2020, 8:37 PM.Take my 45 and outrun em all ..Comment
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Sifton 3030 spring set with their black top collars to match the cam would be my guess. Could be S&S.
Yes, TRW 2800 or 2900 pistons made for S&S. One of the best forged pistons for shovels ever made. Those pistons will yield a listed 9.0:1 compression ratio with the 4 3/4 stroke. You can bet it might be a tenth or two lower, depending on how much the valves are sunk, affecting the volume of the combustion chamber.
Given that, the cam you had was WAY more than needed, giving a soft bottom end in exchange for horsepower in a range of rpm beyond normal operation.
I'm interested to see what Drag's wizard box says about a cam choice. My AccelPro didn't work with my new computer fifteen years ago, so I quit using it.
I would choose a cam that closes the intake valve at around 50 degrees ABDC, at .050/.053 lift timing.
JimLast edited by JBinNC; 03-26-2020, 5:40 AM.Comment
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Interested to see what you come up with! I was glad to not see any scoring in the cylinders, everything seems good in the top end. At least with the front cylinder. So with these 3-7/16 jugs, do I need a special head gasket? By the way this will be going in a kick only street bike if that makes a difference for cam choice.Comment
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Given that those motors are hard on rings, I would rering it since you are this far down. Long stroke, short skirt, and loose clearance means shorter ring life. Standard shovel rings will fit those pistons.
You can use a standard shovel head gasket, but use a good one, no blue Teflon gaskets!
JimComment
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So was I ....
This is with the 105 cam ...
On the head gasket choice ... Hard to beat James Fire Ring ...
If you're up for a little work you could machine a .004 step on the gasket surface of the jugs... That allows for a bit more crush on the metal fire ring ... (Poor Boys O-Ringing, per say)
All of S&S cylinders has that step for the Shovels. ..
Last edited by Dragstews; 03-26-2020, 6:25 AM.Take my 45 and outrun em all ..Comment
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The springs that you took out of my S&S Heads had 3 springs per valve Jesse, I'll have to look at the keepers and all when I get home to see if they look the same.
JakeComment
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Torque curve for that 105 looks better than I would have thought.
JimComment
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All of these cam specs are very new to me and rather than guessing and making a mistake, do you have any suggestions for a cam that fit in the "Choose a cam that closes the intake valve at around 50 degrees ABDC, at .050/.053 lift timing" catagory? From that last picture it looks like the L5 is off the table without head work, what about the #7?Comment
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That cam is not in the database ...
I would need to find the specs and manually load it in order to run the simulator ....Take my 45 and outrun em all ..Comment
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Ya know ....
It might not be a bad idea to do a valve job on those heads ...
That way you get to have a good look at the ware and tear on the valves and guides ... PLUS ... Pack the NEW Springs for whatever cam you do choose to run ....
Be no guessing involved .. !!Take my 45 and outrun em all ..Comment
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Is there any other information you need from me to take the guess work out of choosing a cam that will work with my current setup?Comment
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Yes ....
How many miles do you think that motor has on it since it's been built ... ??
BTW ....
That No.7 cam has a .510" valve lift ....
Your Sifton 105 has .475" ...
Look up Leineweber J-2 ...
That may be a plug & play cam with what you got going on with your springs ...Last edited by Dragstews; 03-26-2020, 7:24 AM.Take my 45 and outrun em all ..Comment
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