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Stock pistons with hotrod cams and headwork question

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  #11  
Old 09-16-2016, 10:35 AM
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Originally Posted by Next In Line
The cams have to match the flow of the heads or else it is just wasting time, money, horsepower and torque.
I think you mean torque, horsepower and then money
But, it is very good advice and sound too.
Btw, I agree too.

Rob
 
  #12  
Old 09-16-2016, 12:27 PM
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Originally Posted by pegskraper
Also my buddy said to the best of his knowledge his bike currently is sitting at 10:1 compression, but that's with s&s pistons on a 95" kit and those heads. I'm guessing the s&s pistons are higher compression than the stock ones..I assumed that decking the heads would increase the compression on my stock 88 but I'm not sure what the actual ratio would be.
Those heads at 82cc and a .030" head gasket will put static CR for your 88"er just a tick over 9:1. The springs will accommodate more lift than the OEM springs at .635" and if looking for a cam to drop in to that configuration with no other modifications, take a look at the S&S 551. Shave another .015"-.020" off the heads, use a .030" head gasket and that 88" will perk up.

Originally Posted by pegskraper
Getting the combustion chamber cc'd would require me taking the piston to tdc then filling it with alcohol am I right? Not sure what goes on in this process. I'm willing to have a "pretty good" cam based on expert guesswork based on my situation. I guess I'm more worried about cratering the engine with an insane cam that causes valve to piston contact.
Have you already installed the modified heads? If so, the heads really should be removed to get an accurate reading of chamber volume. You could take a compression reading and take a stab that way but it won't be a true reading.

You will need to re-jet the carb.e-jetting carb. IMHO, worth taking the heads $250 and giving it a shot; the 88" OEM heads are a real bottleneck.

Not discounting or disagreeing with any of the previously posted info; you asked for options so I gave you one...............
 
  #13  
Old 09-17-2016, 10:41 AM
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As I said before the heads are currently on my friend's bike, he is going to be pulling them once the snow flies. I'm just strategizing or trying to plan what I'm going to do when it comes time for me to fix my cam tensioners and cam the bike at the same time. I live in grande prairie alberta, its a 5 hour drive to edmonton where the headwork was done so not the easiest thing to do in order to check combustion chamber specs, etc. I'm planning on doing the work myself in my garage when it's -20c with 3 feet of snow
 
  #14  
Old 09-19-2016, 06:09 AM
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...............or bore to 98" then you can set it up to have great power from bottom to top, and many cams can accomodate then.
Your going to be spending money on a top end gasket set(approx $110.00).....so at that point your only $540.00 away from pistons/cylinder boring/ring end gaps set, and installed, here.
Scott
 
  #15  
Old 09-19-2016, 12:02 PM
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Originally Posted by pegskraper
As I said before the heads are currently on my friend's bike, he is going to be pulling them once the snow flies. I'm just strategizing or trying to plan what I'm going to do when it comes time for me to fix my cam tensioners and cam the bike at the same time. I live in grande prairie alberta, its a 5 hour drive to edmonton where the headwork was done so not the easiest thing to do in order to check combustion chamber specs, etc. I'm planning on doing the work myself in my garage when it's -20c with 3 feet of snow
Easy to check chamber volume in your garage; might want to consider a salamander to warm things up a bit though. Coming from south Texas, I cannot relate to -20*C but can say that the garage would have to be heated for me to work when the outside ambient temp was -20*C. Still liking the S&S 551 to drop in with those heads.

http://www.diyporting.com/cc.html
 
  #16  
Old 09-20-2016, 10:01 AM
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Have a plan, like what Hillside has mentioned otherwise you risk going thru what your buddy is going thru, trying to pawn off horribly overpriced heads on a "buddy" because the parts aren't even close to working together at all.
 
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