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[skyhook]

my theory is that the stock cams are the main reason that the 110's leak from the rear head gasket...I'd like to hear from folks who've swithched cams and whether you've had the leak...please list which cams and how many miles...my '08 fxdse2 has se257 cams, 6k miles and no leaks

[ultrafxr]

my theory is that the stock cams are the main reason that the 110's leak from the rear head gasket...I'd like to hear from folks who've swithched cams and whether you've had the leak...please list which cams and how many miles...my '08 fxdse2 has se257 cams, 6k miles and no leaks

Not changed cams but leaks do develop at different times.  Original motor had lead at 7k, repaired then leak again with about 4k.  New motor did not develop leak until almost 20k and at 23k it is still just quite small.  Hope to get the 0905 program done late this month or next.

[hd-dude]

Sky;
Curious why you would think the cams are the cause of the head gasket leak? Granted the short duration and timing of the 255 cam makes the motor run HOT but just curious of your theory.

[Coyote.]

Sky;
Curious why you would think the cams are the cause of the head gasket leak? Granted the short duration and timing of the 255 cam makes the motor run HOT but just curious of your theory.

Yeah, me too. I don't get that one... but to answer your question, I'm on my 3rd cam. I had two leaks with the stock one. Another leak with the POS cam the dealer recommended. My 3rd cam runs great. No leak so far but I also have Revolution cylinders now so .....

[LRebel]

Yeah, me too. I don't get that one... but to answer your question, I'm on my 3rd cam. I had two leaks with the stock one. Another leak with the POS cam the dealer recommended. My 3rd cam runs great. No leak so far but I also have Revolution cylinders now so .....

What cam did the dealer recommend..... and what cam are you running now?

[bisounours]

On my CUSE2 '07, I've changed the cams for SE 251.
Leaks on the rear head gasket 2000 miles later.

Sorry, I validate not your theory

Jacques

[skyhook]

I think it's a combination of at least two things that cause the leaks:

1.  the cold cranking pressure on a stock 110" measures around 215# with the compression releases turned off...this is very high...I like 185# for a mild build and am running 200# in my bike but I do not allow the rear head to go above 330* F...in order to run a motor at 215# compression the timing must be retarded and this makes it run hotter

2.  people have reported temperatures of 390* F at the rear head on a stock 110"...combine this much heat with the high compression and it's no wonder the head gasket blows, cylinder liner moves, etc

stock cams close the intake valve at 25* adbc and have very little overlap...changing to a cam with around 42* intake close and 35* or more overlap will lower compression and allow the motor to breathe much better

when my bike had 100 miles, I had it built with ported 96" heads, cometic .030" gaskets, se257 cams, supertrapp 2 into 1, and advanced tune with power commander...it hasn't leaked in 6k miles and I'm wondering if I'm just lucky or if others are having the same experience

[bigdave110]

I just got me 08 2 months ago.
Put s&s 570 gear drive cams in from the get go.
5480 on the bike now.
no leaks yet, but many people didnt have leaks till much higher miles, so not sure if this helps.
how ever, i do agree with some of your theory.
i also put on d&d fat cat, arlen ness big sucka, and race tuner. lenelle fan.
i changed cams for some of the same reasons you dont like fact cams.
no overlap, bad duration, ect.  basically an emission friendly cam.  *hate it*
every one kept telling me to wait till break in for cams, but hell ofter 500 or 1000 miles the motor has been run so hot
damage is already done, IMHO.
After changed all maps, ve tables, cam timing my bike runs great, no heat problems, no starting problems.
Lucky so far I guess, but i will take it, right.
Hope this helps,.
O'yea , I would do it this way again.
dave

[DCFIREMANN]

Skyhook has the idea. The leaks IMHO are all heat related. I don't care what anyone has said in the past. If you change the cams, air cleaner and exhaust remap with a much richer mixture it will cool the motor down. The 103's never had the problem. Most had changed the exhaust, air cleaner and remapped the bikes. They were also a lot cooler running fro the factory. I can tell you when I rode Punkin home it was the hottest running bike I had ever ridden. It took about 3 days to get the parts and make the upgrades. It ran well and ran cool. I have been happy with this bike from day 3!!!!!

Be Safe

THE DAWG