In the original post you wrote that you had 89 cc heads. Which heads do you have? Do you know what they flow?

 

Read up on these.. It's a science..

https://www.rbracing-rsr.com/machcalc.html

https://www.rbracing-rsr.com/lovellgascalc.html

 

Your original post says 89cc S&S heads, are you now saying you already have 79cc S&S heads on it and are planning to use those?

 

Yes my original post says 89cc S&S heads but I didn’t make myself clear from the get go, so here it is:

The bike is an 05 Dyna Superglide custom, I’m currently running:
S&S 97” kit
S&S 79cc heads (with the 0.650” lift springs)
S&S 585s chain
S&S hyd camplate & upgraded pump
S&S premium Quickee pushrods & tappets
06 up TB bored to 50mm with 4.9 injectors
Bassani Road Rage II B1 Power
3.37 gearing
Baker OD6
Barnet scorpion lockup clutch
According to BigBoyz calculator it’s at 10.33 static & corrected 9.27

Chain conversion
Lyndal twin disk setup up front
Lyndal rear
Legends carts up front, ohlins rear shocks
Metmachex Aluminium Swingarm
Lithium battery
Cast 13 spoke wheels (powder coated)
Turns out 109hp and 108tq

I’ve done all these mods myself, it was bone stock when I got her and you don’t need to be a genius to understand how heavily invested I am in this machine.

The original plan was to reuse the heads and cc them to 89cc.
Use a -10cc piston with 117 S&S cylinders and a 0.030 gasket to get 10:1 static.
Use an Andrew’s 57, 54 or woods 6G cam.
Use my exhaust.
Use my current 50mm TB and 4.9 injectors for what would be a ‘mild 117’….

Now after hearing lots of good info, I’ve been persuaded to avoid this ‘original plan’ and perhaps look at re-using my 585s and up the comp to 10.5 (by using flat tops and adjusting head cc’s in order to accommodate my 585s. Use the money I’ve saved by not replacing cams and invest that in a HPI 55/58 or similar…

Now the question remains can I use these S&S 79cc heads by just cc’ing them to my required 10.5 or will I need a valve job too? Or should I put ‘em on the shelf and grab some oem heads to modify?
I would prefer to reuse them as it would be wasteful not to.

Apologies for not being clear at the start, in my excuse, I was initially only asking for cam advice.
So there you have it…

 

Check out post #6. South Texas, not 120* but can see 108*-110* late summer. 93 octane, no issue with detonation, hard hot starts, etc. but it was tuned by one of the best in Texas, probably one of the best nationwide. Not trying to start an argument, just pointing out that high compression motors can have good street manners and avoid high heat issues with the right tune.

 

As has been suggested more than once, sell the S&S heads and use the funds to purchase a set of OEM heads, preferably '06 up but since going out for porting and machine work (compression releases) the year really doesn't matter. Select a head porter, WFO Larry has been mentioned, give him a call (he will have good advice on cam selection as well) tell him your plan and turn him loose on your heads.

How about posting a couple of pics of the bike; I would like to see it.

 

Thanks for these links, I’ve plugged my dimensions into the calculator and I can see that my current valve sizes are a touch too small for absolute maximum VE at 6000rpm, @ 5800 it just tips over the 0.6 inlet valve MACH index.
Great help 👍

 

Give WFO Larry a call.. I'll bet he'll have some suggestions..

 

This is my latest one, No Tq in this one as the dyno guy had some issues with leads on the day?? but he assured me it was 108.69.

 

I think in the UK you might be better off doing a very responsive 107 than diving into a 117 rabbit hole.