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[100GOLD]

Hi fellas,
 Fist want to thank you for all the great info in here.

History.....I'm in the process of rebuilding the motor on my 03 serk. Bike has 32k on it. At 22k it ate a set of JIMS SE lifters. I rebuilt the cam chest and it lasted another 10k.

This time, the cam plate bearing went TU and finished the job.

I'm considering taking some stress off the cam chest by lowering the spring rate in these heads a bit. I rareley get past the 5500 rpm mark and if I do, it's very brief.

I'd welcome opinions and suggestions.

The build is 17072 heads. 251 SE cams. HPI 51MM TB. SE forged crank,welded and balanced. Matching SE pistons to the heads. 2-1 Thunder header. SERT. Terminal velocity.

Bike consistently dynoed at 115/117,hp/tq. Great seat of the pants and pulled where it needed to pull as a bagger.

Thanks for reading!

[prodrag1320]

have someone with a spring tester test them (send them here,ill test them for you,no charge)

[grc]

See attachment from the current SE catalog.  It may give you a clue, or of course you might need to just measure them to be sure.


Jerry

[HD Street Performance]

Happy to oblige. These measurements were taken on a Rimac tester recently calibrated. 75 deg F. Springs came off CVO103 heads with 5600 miles.
182# @ 1.8
Spring Rate= 478#
Coil Bind 1.135
YMMV

[100GOLD]

Thankyou men! Just what I needed. I'll start from there and see if my builder has a tester.

[prodrag1320]

if your engine builder dosnt have a spring tester,ide find another builder

[100GOLD]

Yup.....good advice. I wish they had more of your sport on TV Prodrag. That is amazing what those machines will do in the quarter mile. I enjoy that more than the AA Funny cars.

I should have this build sorted out by the time I get done. I think it was just a matter of a very good top end being put on the bike and nothing done to the bottom end to support it. The pinion shaft had runout so bad that it was grooved and unreuseable.

[prodrag1320]

15 time champ,John Force said we`re nuts for riding these things!!

[HD Street Performance]

Just caught the fact that you are using the SE not the CVO head.
Different specifications on those. I don't have a set handy to measure (until mid next week) but the book spec which we saw was a YMMV is 195#@1.8 spring pack dist. 505# spring rate. More pressure and rate than required with that cam and the valves used in these heads IMHO.
I suggest changing to an AV&V HVS-6500s from Goodson.com.

[100GOLD]

Excellent. DH, do you think that I'm on the right track to gain some longevity in this build?

And Prodrag, John Force is a very wise man. lol......If you're interested, search youtube for my buddy IdahoRob and Maxdout.

Probably boring for you but fun for us rednecks out here in Idaho.