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SE 103 kit CR?

5K views 25 replies 8 participants last post by  arealinvestor  
#1 ·
Anyone know what the CR is with the SE 103 kit, PN#29903-07a, cast pistons? A search of SE parts shows zippo..
 
#3 ·
Is this the kit that comes with the SE255 cams?

If so it is 10.0 to 1. This is also just a tad bit high for those cams as it makes hot start a little tough and could ping if the tune is not spot on. Mine does not ping but if I were to do mine again I'd put in compression releases.

Chris
 
#4 ·
I just looked in the SE catalog and see the kit you're talking about.
The pics of the pistons in the kit I mentioned above look identical to the kit your looking at so they must be the same.:spank:

I'm pretty sure the dealership has a brake down of the parts with numbers in the kit. If they don't have the info on compression ratio but the pistons part numbers are the same as my kit it would be at 10 to 1.

Chris
 
#5 ·
103ci with 10:1 comp that sounds a little high to me!!!!!!!!!!the SE 110 cvo from the factory doesn't have 10 to 1 comp unless you switch to the high comp piston.
 
#7 ·
I would stop on by your local Stealer and ask for the supplement SE parts catalog. The part number for the one used in 07 is "99557-07SE" so the one used for 08 might end in 08. If the new one don't have the info. you need, you can always call the MOCO.

If I had to guess I would say it's no more than 9.0:1 CR with the head gaskets in the kit.
 
#13 ·
Diggerpine here; The SE 103 kit, PN#29903-07A does not come with the SE-255 cams. The kit uses the stock cams, I could be wrong but I would say the CR is the same as stock. The only difference would be larger flat-top pistons.

Ride Safe!
Steven
 
#20 ·
There is a boost with bigger flattops, even if the piston has the same negative deck height. With a piston with the proper deck height and an .030 gasket, you are getting close to 9.5:1 on a 96 to 103 conversion, maybe 9.6:1. It all depends on the combustion volume, some of the 96 engine heads have much more volume than their big brothers, the 88in heads. The only sure way is to do the math, and that means measuring and CCing to be sure.

As far as just bolting on some heads and a cam, you could get lucky. Remember that what Andrews says and what is said here is a little different. A little difference in compression(lower) isn't always bad, sometimes it will tune just as well or better. You have to take the advnace out of most high comp builds anyway(that is de-tuning)
 
#16 ·
Thanks

Thanks all for your input - I now think the CR will be 9.2 with stock cams, talked to Andrews and they have a new cam (54H) for 103 engines with a CR less than 10.0, supposed to be strong to 5600, and with my light Dyna should really haul butt. Will end up costing me less than a grand. ( got the 103 for $400 new from dealer)
 
#18 ·
Arealinvestor, I think a lot of us try to find the happy medium between cost and engine size. I know I'm not rich and I may have to compromise some when I do my build this winter. I've noticed that ceraaa42 has said in more than one post that he was happy with his build and he didn't spend a fortune getting the results that his dyno sheet supports.

What build are you going too? What bike are you buying? These are all things that ceraaa42 already has figured out and has given his input in this thread based on owning the SE 103 kit.
 
#19 ·
@gree:.I agree we must sacrifice somewhat due to money constraints.
 
#24 ·
2008 ultra classic.my budget 8,000-9,000
 
#25 ·
Hey! That'll work.

Out comes the engine, send to Randy (King of Cubes), tried and true 124 kit goes in with everthing that needs done to make a nice engine, heavy clutch, yep your there.

What's your time frame?

How about some pics of the scoot?

Chris