Has anyone run these heads?

 

nevermind... wrong heads

 

I know an Indy in Mesa, Az. that swears by them. If you are going on a stock 96" the 79 cc will give 10.16:1 compression. On a 103" they will bump you up to 10.8:1. Both of those were with a .030 head gasket. A .040 head gasket on the 103" will get you back down to 10.57:1. They have pretty big intake valves which usually means a loss of low end performance, but not necessarily. The Indy I was talking about used them with an S&S 106 kit (4 1/2" stroker) on his '02 with S&S 585 cams and he can spin the rear tire by wicking the throttle.

 

I'm thinking about doing a 103 with them and keeping my 48 cams. With a 30 head gasket ccp is 195 assuming zero deck with the 89cc heads. Probably end up with a few in the hole, which is fine by me...

 

I'm running the 89CC heads on a 106" with 583 cams. The performance boost was very noticeable. My numbers on a dyno were not as good as we hoped but the bike is out of tune. Got 86HP/97TQ. I'm waiting on a Mastertune so I can take it for a full dyno tune. I've since swapped my Big Shot for a Fat Cat and that made a big difference too. Everyone that's seen the build expected 10-15 more in each number.

The TQ line hits max at 2700 and stays above 90 out to 4800. That seemed to impress several people.

I think the heads work pretty well. Didn't go with a 30 head gasket. I haven't tried to spin the wheel but I do know it goes to 100 a lot quicker than it used to.

I'll share what happens at the tuner when it gets done. Hopefully by month's end.

 

anyone know what the 89cc heads will end at compression wise on a 103"

 

Bigboyz says 9.77 with zero deck and 30 head gasket. I'd go with more comp if I was using different cams....

 

From S&S web site:

103" 79cc 10.2/11.1* 89cc 9.3/10.1*

*S&S pop-up piston

What causes the big difference between these numbers and the ones from BigBoyz?

 

I currently have stock heads on an S&S 106 w/ 551 cams, TMax AutoTune, and V&H ProPipe. Switching to SuperTrapp SuperMeg next week, then heads and TB are next.

S&S tech said if I want big tq I should keep the 551s and add 89 cc heads (to keep CR low), 58 cm TB, and regular SE injectors. S&S said that should deliver ~ 110hp/125 tq.

 

My numbers were probably a little off because I didn't adjust the calculator to reflect the stock compression before starting. Going with the stock '13 compression of 9.6:1 on a 103" using the 79 cc heads with a .030 head gasket will give final compression of 10.46:1. The same set-up with a .045 head gasket will give a static compression of 10.15:1. The '13 with the 89 cc heads and a .045 head gasket give a static compression of 9.26:1. It all depends on what you start with and what head gaskets you use. You will notice the higher compressions on each head require the use of pop-up pistons. The calculator is pretty accurate, but like any computer it just reflects the data that's inputted.