Sifton cam swap to Andrews
#1
Sifton cam swap to Andrews
A buddy of mine recently acquired a, non running 1985 FLHX. It was leaking oil like I've never seen before so I told him to pick up James or Cometic engine gasket kit and we'll tear the engine down, inspect it and seal it up.
Well, I got into it and find it's got a Sifton 141-EV cam and adjustable lifters with unknown other mods. I've heard that particular cam isn't very good and I'm wondering if we could swap it with an Andrews EV-3/27. Or, is that a good enough cam for just hauling *** once in a while? He's not a racer by any means.
I also notice that particular cam isn't a bolt in style. What other mods have been done to this engine to accommodate that cam?
I can get some pictures if you need to have a look. Thanks for the help!
Well, I got into it and find it's got a Sifton 141-EV cam and adjustable lifters with unknown other mods. I've heard that particular cam isn't very good and I'm wondering if we could swap it with an Andrews EV-3/27. Or, is that a good enough cam for just hauling *** once in a while? He's not a racer by any means.
I also notice that particular cam isn't a bolt in style. What other mods have been done to this engine to accommodate that cam?
I can get some pictures if you need to have a look. Thanks for the help!
#2
Wow, thats all i can say is wow, that cam is got some duration, i bet that big bike was a slug, and if it doesnt have any added piston to it, it was probably slower than stock .......anyway, altho nightrider doesnt designate it as a bolt in, with only .480 lift, it doesnt require any guide cutting or clearancing, only thing that comes to mind is with the amount of duration on the exhaust side, they may wont you to use valve springs??? anyway, you are def on track with a ev27 or 3, id even look at vthunder 3010 or 3020, all four have bolt in potential. hope that helps. chad.
#3
I used an EV27 cam in my 1990 FLHS until I introduced more serious mods. Can you tell if it still has the stock compression ratio?
The two main sources of leaks on early Evos were the base gaskets and gearbox oil seal, also to a lesser degree the lifter housings. Having fixed those on my bike I never had any repeat problems.
The two main sources of leaks on early Evos were the base gaskets and gearbox oil seal, also to a lesser degree the lifter housings. Having fixed those on my bike I never had any repeat problems.
#4
Thanks for the quick replies!
I can't tell the stroke with the heads off maybe I'll measure it when I get out there and pull the jugs. There's A LOT of carbon in the center of the pistons and the valves, he told me the plugs were black. Whoever did this did nothing with the carb obviously. It has the Torrington bearing in it, I don't recall the year they did away with the bearing? Early 90's?
I can't tell the stroke with the heads off maybe I'll measure it when I get out there and pull the jugs. There's A LOT of carbon in the center of the pistons and the valves, he told me the plugs were black. Whoever did this did nothing with the carb obviously. It has the Torrington bearing in it, I don't recall the year they did away with the bearing? Early 90's?
#6
One reason cams are listed as "non bolt-in" is obviously a high lift factor. Another reason is extra long duration generally requires a lot of compression, as well as exhaust and intake modifications to realize suitable power gains.
Another less obvious reason is that some cams are ground with a smaller base circle which is incompatible with the stock pushrod length.
#7
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#8
#9
A ruler will be good enough to do this! Stock stroke is 4 1/4", usual 89" stroker crank (I had one in my evo) is 4 5/8". Will be pretty obvious if it's been stroked, which will suggest other tuning mods such as ported heads, higher comp.
#10
UPDATED with pictures
I got out to the garage and snapped a couple of pictures:
These are not stock pistons. Anybody know the brand? The stroke is 4 1/8" but then there's the dome.
Will these work with the Sifton cam? Mike would rather not buy a cam if he can get away with what's already supplied.
These are not stock pistons. Anybody know the brand? The stroke is 4 1/8" but then there's the dome.
Will these work with the Sifton cam? Mike would rather not buy a cam if he can get away with what's already supplied.