Installing Andrews 57 on a Dyna 06
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From: san antonio
The mistake some make with the 57 cams is not providing enough compression. IIRC, the 57 like about 10.2 static. Which in a 98" configuration would need a dome piston in lieu of flat top.
Last edited by djl; Jan 21, 2026 at 08:01 AM.
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Road Captain
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From: Stockholm
Andrews 26 MLS 0.040"
Andrews 57 MLS 0.040"
If I use a 0.030" MLS instead, Big Boyz calculates the compression to 188.0.
Maybe I will go with the MLS 0.030".
Last edited by OakMountainRider; Jan 21, 2026 at 10:27 AM.
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From: san antonio
Couple of things to consider. How sure are you the chamber volume is 85cc? Have you meausred? 86cc is not uncommon in the improved '06 heads. What pistons give you the 1.2cc dome: just curious. For sure run the .030" head gasket but give some thought to shaving .030" off your heads;
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Road Captain
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From: Stockholm
Couple of things to consider. How sure are you the chamber volume is 85cc? Have you meausred? 86cc is not uncommon in the improved '06 heads. What pistons give you the 1.2cc dome: just curious. For sure run the .030" head gasket but give some thought to shaving .030" off your heads;
Chambers are measured. I did that three years ago. Front 84,8 CC and rear 85,2 CC. So I am pretty sure. I measured 192 PSI front and 194 rear last year with the 26. It was higher than calculated. I think it was because of the carbon build up, both on the pistons and in the chambers.
I will do the clay test a soon as I have put the heads together. I ended up with Manley 0.600", which will arrive from Germany soon.. They are about 5-10 % stronger than S&S 0.585", not as strong as Kibblewhite. I have replaced the exhaust valves. The stock did not have a good surface against the seat. Looked like carbon and metal melted together.
Last edited by OakMountainRider; Jan 21, 2026 at 01:26 PM.
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Road Captain
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From: Stockholm
Couple of things to consider. How sure are you the chamber volume is 85cc? Have you meausred? 86cc is not uncommon in the improved '06 heads. What pistons give you the 1.2cc dome: just curious. For sure run the .030" head gasket but give some thought to shaving .030" off your heads;
Last edited by OakMountainRider; Jan 21, 2026 at 11:11 PM.
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From: Poolville
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From: Stockholm
I agree with @djl ...A minimum of 10.0:1 for the 38* ivc.. I would try to return the pistons you have and go with a +3.0 cc piston.. You will notice an increase in power because of the cubic inch increase but will not really satisfy the cam of choice..
What I can do, as far as I can see, is to go for the 0.030 MLS and maybe I can see if someone can shave a little on the heads. (But I will make the clay test first to see if I can do that.) Anyway, asking Chat TGP what a 0.01 shave will do to 85 CC, it says 83.2 CC.
And when I put this in the Big Boyz it actually says 10.0:1 static, which will result in 192.3 psi with the 57 cam.
Last edited by OakMountainRider; Jan 22, 2026 at 08:41 AM.
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From: Poolville
To get to 10:1 compression you will need to remove .020" off the cylinder head.. By what i was told .006" = 1cc but the graduation changes because of the taper in the combustion chamber..
Edited.. technically you should be able to go 30,000 without a problem and still have plenty of valve to piston clearance.. which will yield 10.2:1.. The sweet spot for that cam..
Edited.. technically you should be able to go 30,000 without a problem and still have plenty of valve to piston clearance.. which will yield 10.2:1.. The sweet spot for that cam..
Last edited by 98hotrodfatboy; Jan 22, 2026 at 09:01 AM.
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Road Captain
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From: Stockholm
To get to 10:1 compression you will need to remove .020" off the cylinder head.. By what i was told .006" = 1cc but the graduation changes because of the taper in the combustion chamber..
Edited.. technically you should be able to go 30,000 without a problem and still have plenty of valve to piston clearance.. which will yield 10.2:1.. The sweet spot for that cam..
Edited.. technically you should be able to go 30,000 without a problem and still have plenty of valve to piston clearance.. which will yield 10.2:1.. The sweet spot for that cam..
Last edited by OakMountainRider; Jan 22, 2026 at 09:25 AM.