Motor Rebuild
#1
Motor Rebuild
Snow is gonna start flying here soon so I'm getting prepped to rebuild the motor on my 88 springer. It's got min. 50000 miles on it (speedo was broken when i bought bike) so I think its time to dbl check the motor. This will be my first harley rebuild just looking for some advice on what cam, lifters and pushrods to go with. I plan on using the torrington cam bearing. Any other advice would be great .
#2
After having a lifter come apart at jut under 50k, I would say that' a good move. I put a ev-27 in my '93 and it ran good and seems to be a popular choice ,but there are others. You don't really need adjustable push rods ,you can use stock ones if looking to save some $$$.But, be sure to check out the lower end if you have that many miles on it. Would be a shame to build up the top end, then have the lower end blow out on you.,,
#3
I'd stick with your stock pushrods The weak link in adjustables are the threads and can losen or even bend,snap at that point. Consider getting lifters for that new cam. Rocker arms and shafts,Valves,viton valve seals. Have your valve springs checked or just replace'm. Nothing wrong with replacing what you can,with Harley parts.
#4
#5
How much of the motor do you intend to rebuild? I reckon a change of cam and a top-end overhaul will be OK on your current bottom end, but if you are thinking of increasing compression and porting the heads you could shorten the life of the bottom-end.
Its a long time ago now, but a friend did a top-end overhaul of his car engine, ground the valves in and fitted new springs, shortly before going off on the annual family vacation. Flying along with his new-found improved performance the crank siezed, before they got to their destination!
So if all is OK with your bike, but you would like to upgrade the cam, leave the rest as it is. But if you intend doing a crankshaft up thorough rebuild, there are specialists here on HDF who can up your compression, port your heads and help you with a serious improvement in performance.
In summary I suggest you have two possibilities, the gentle approach, or pull the stops out!
Its a long time ago now, but a friend did a top-end overhaul of his car engine, ground the valves in and fitted new springs, shortly before going off on the annual family vacation. Flying along with his new-found improved performance the crank siezed, before they got to their destination!
So if all is OK with your bike, but you would like to upgrade the cam, leave the rest as it is. But if you intend doing a crankshaft up thorough rebuild, there are specialists here on HDF who can up your compression, port your heads and help you with a serious improvement in performance.
In summary I suggest you have two possibilities, the gentle approach, or pull the stops out!
#6
I did my motor last winter including the bottom end, you don;t really have a whole lotta miles on the motor for bottom end but as Graham said if you increase compression there's more stress on bottom end, if you do the bottom end be prepared for min. $300-$400 mechanic shop hrs. I put a Headquarters Rumble stick cam and andrews quick install pushrods, oem lifters and all new valves, pistons/rings, as well as torrington cam bearing. Make sure you go over the oil pump as well. And no use stopping there you might as well put a new ignition and single fire coil. Ok carried away a bit. Don;t forget new cylinder studs if you think they;ve been stretched at all, and keep in mind the next time you torque them they may stretch to max or worse yet pull the alluminum threads out of the cases and need time serts installed. Damn what an interesting year this was for the old girl.
#7
I'm just gonna do the top end. I have to change out the gaskets on the cylinders so they'll be coming off. New rings and hone the cylinders but not increasing compression or stroke. Do the cam, lifters, probably stay with solid pushrods. I plan on taking the valves and rocker arms etc. as i go through it depending on how they are. Going with the torrington for sure. either an ev 23 or 27. Not quite sure yet as I don't ride at high rpms much just like bombing around and having the power on the low end.
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#8
#9
I'm just gonna do the top end. I have to change out the gaskets on the cylinders so they'll be coming off. New rings and hone the cylinders but not increasing compression or stroke. Do the cam, lifters, probably stay with solid pushrods. I plan on taking the valves and rocker arms etc. as i go through it depending on how they are. Going with the torrington for sure. either an ev 23 or 27. Not quite sure yet as I don't ride at high rpms much just like bombing around and having the power on the low end.
#10