Another cam question, but different 🤔🙂
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Stage IV
Joined: May 2022
Posts: 4
Likes: 0
From: Canada eh
Another cam question, but different 🤔🙂
Hey all , any cam/engine gurus out there please read....
I got a '10 fatbob 96" , v&h hi output short exhaust ,A/C Andrews 48h cams and tuned with techno research ..love this bike and the blast off the line..but of course, we're never happy, so this year had the jugs bored to 103" , and used Harley's flattop pistons with a .040 head gasket and got mild port job while it was in there.
After putting back together first start seemed really tight, like my battery was dead, load tested the battery and it was green but marginal so bought a battery, no problems ,, problem I'm having is with hot starts , from the garage cold starts no problem, after riding ,if I make a quick stop and jump back on, it seems hard to start ,will take a few revolution more before it fires, instead of immediately. also think starter was skipping the ring gear during hot starts, sounded like ****, so put new starter drive in which seemed to help,, but only for a bit . The bike starts everytime it just makes a terrible racket trying when hot . I checked compression in the bike and it was 195 which seems high , my question is are my Andrews 48 not suited to my combo now? Could they be the reason for my problems, like I said bike starts, and runs hard, just at startup having these issues, when I hit starter button and it hits compression stroke seems like is having hard time,,
Would different cams ,,like the 555, or 57h or the mr103(compression release) help you think ? Anyone?
I got a '10 fatbob 96" , v&h hi output short exhaust ,A/C Andrews 48h cams and tuned with techno research ..love this bike and the blast off the line..but of course, we're never happy, so this year had the jugs bored to 103" , and used Harley's flattop pistons with a .040 head gasket and got mild port job while it was in there.
After putting back together first start seemed really tight, like my battery was dead, load tested the battery and it was green but marginal so bought a battery, no problems ,, problem I'm having is with hot starts , from the garage cold starts no problem, after riding ,if I make a quick stop and jump back on, it seems hard to start ,will take a few revolution more before it fires, instead of immediately. also think starter was skipping the ring gear during hot starts, sounded like ****, so put new starter drive in which seemed to help,, but only for a bit . The bike starts everytime it just makes a terrible racket trying when hot . I checked compression in the bike and it was 195 which seems high , my question is are my Andrews 48 not suited to my combo now? Could they be the reason for my problems, like I said bike starts, and runs hard, just at startup having these issues, when I hit starter button and it hits compression stroke seems like is having hard time,,
Would different cams ,,like the 555, or 57h or the mr103(compression release) help you think ? Anyone?
Road Captain
Joined: Mar 2020
Posts: 654
Likes: 356
From: Sierra foothills
Not a guru but
If it were me I would try the MR103. Close enough to the 48's you like with added benefit of easy start. At 195psi on a hot day restart you need some compression release help. Other cams you mentioned would feel softer off the bottom and would benefit more static compression IMO and then you'll still need releases
If it were me I would try the MR103. Close enough to the 48's you like with added benefit of easy start. At 195psi on a hot day restart you need some compression release help. Other cams you mentioned would feel softer off the bottom and would benefit more static compression IMO and then you'll still need releases
Grand HDF Member
Joined: Sep 2017
Posts: 4,359
Likes: 1,219
From: Dubuque, IA
195 is not high. Hell, I'm running 212. But you need compression releases. New bikes with the 103 have automatic compression releases(ACRs). You could have manuals put in(MCRs). I wouldn't change to S&S cams just to get easy start cams. Those 48s and your compression are spot on where it should be.
Lowering compression will just cost power. Not there's anything wrong with the other cams you mention and I actually prefer them over the 48s but I would then want to bump my compression accordingly as well to be where it's at now.
Lowering compression will just cost power. Not there's anything wrong with the other cams you mention and I actually prefer them over the 48s but I would then want to bump my compression accordingly as well to be where it's at now.
Last edited by 60Gunner; Jun 1, 2022 at 11:19 AM.
Road Master
Joined: Mar 2013
Posts: 817
Likes: 380
From: Central Ohio
Agree on the compression releases, might as well pull the heads and have MCRs put in unless you're into wiring stuff. A stock 103 with the 57h can crank hard too if there's no comp release. Maybe pull a touch of timing during crank? What CCA was the battery?
Road Warrior
Joined: Jun 2007
Posts: 1,523
Likes: 312
From: Out of Commiefornia!
Yep - MCRs for the win. I too have an Andrews cam (31H) in my 07, and pumped it up to a 107. Had MCRs installed and it did the trick. I dont often have to use them, but when I get a hard start it is simple to push the releases and fire it up easily.
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Tourer
Joined: Oct 2010
Posts: 406
Likes: 240
From: NW MO
A couple cheaper things you can do to help
install a -4 degree crank sprocket (Andrews has one that is +4 one way and -4 flipped over)
adjustable pushrods- adjust the intake lifters a flat off the bottom (you need to understand what youre doing when doing this). On a hot shutdown the lifters bleed down pretty quickly, and if it parks on an intake lobe then that cylinder will have much higher cranking pressure. Adjusted off the bottom the lifter cant bleed down
install a -4 degree crank sprocket (Andrews has one that is +4 one way and -4 flipped over)
adjustable pushrods- adjust the intake lifters a flat off the bottom (you need to understand what youre doing when doing this). On a hot shutdown the lifters bleed down pretty quickly, and if it parks on an intake lobe then that cylinder will have much higher cranking pressure. Adjusted off the bottom the lifter cant bleed down
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Seasoned HDF Member
Joined: Mar 2010
Posts: 21,095
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From: Poolville
That there is the best and cheapest solution if you can wrench..