Hey guys,

I have a buddy with a 2000 dyna superglide that just spent 5500 on performance upgrades. He is going to sell me some heads off his bike that he got work done to because he wants heads that flow even more. He did a 95" kit, cams, SE oilpump/camplate/tensioners, motor mounts,etc.

He spent a grand I think getting the heads done and he'll sell them to me for 250, so I kind of want to grab them. He got .630 lift springs put in, a 3 angle valveseat grind, exhaust ported and the heads got decked .020".

I have an 02 dyna lowrider with a stock 88" engine with 47k kms. I need to do the tensioners, so I was originally going to put in some mild cams and maybe a gear drive, but these heads increase the compression to 10:1 so I would have to run different cams etc. Now I'm leaning towards the screaming eagle camplate/oilpump upgrade so I can run hydraulic tensioners because it's cheaper/easier to do.

I'm not planning on doing a 95" kit, I want to keep the stock pistons. I'm not sure what kind of cam lift would work with the stock pistons, without running the risk of the valves smashing into the piston on exhaust/overlap.

What are my options here? Run a less aggressive cam with maybe .550 lift? Thicker head gasket? Would I need to run a cam specific to a 10:1 ratio? Should I stick with my original plan to go mild with the cam and keep the stock heads and springs? I like the deal, and I would like to squeeze as much power as I can out of the engine in 88" form. I have the stock keihin carb with a 46 slow jet, stock main jet, nokk needle shimmed .020", stage 1.

Any advice here would be great, thanks!

 

The cams have to match the flow of the heads or else it is just wasting time, money, horsepower and torque.

 

S&S 570 cam will do that good at 10:1.

 

We don't know just exactly what head work your pal's heads have had done to them, but to be blunt you are wasting your time and money if you don't build your engine to a similar standard as his was. Get in touch with the tuning shop who prepared the heads that are telling you to buy them! Take their advice, or pass on the heads.

 

I hope the inlet was ported too? and bigger valves?

good advice from the guys above..

 

.020" removed from the 85cc chamber(or larger), which is about a touch over 3cc's, is NOT going to pull an 88" to 10.0 cr.
Knowing the exact cc's of that chamber will allow you to make a very good decision on a cam that'll work for you.
Scott

 

along with whats been said here,you`ll want to look at TDC lift,not total lift for valve to valve & valve to piston contact.ide get the heads to a good builder & have them CC`d & evaluated

 

Thanks for the replies! The heads were built by George Welch out of Edmonton. All that's been done to them I have listed, stock size valves which is why my buddy is going to get another set of heads done with bigger valves for more flow. The heads are currently on my buddies bike, which has s&s pistons on it, he said the reliefs cut out of the pistons are deeper than the stock pistons, which is what got me to thinking about valve clearance vs cam lift with the stock pistons.

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.

 

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.

 

George Welch is best placed to help you swap those heads over to your bike! Give him a call.