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S&s 113 sidewinder compression

13K views 10 replies 5 participants last post by  hillcat 
#1 ·
I new to harleys I got a 99 heritage with a s&s 113 super sidewinder not sure on the cam, I ran a compression test tonight and I'm getting around 100 on both with the throttle closed and 215-220 with the throttle open, engine was cool, no compression reliefs, is this right, I've been having a hard time getting the bike tuned perfect it runs real strong but I can tell it's not completely right
 
#2 ·
You leave a lot to guess here..
What is not right?
That is a big question to answer with no input
CCP with throttle open and ign by-passed is the correct way.
Next would be a leak dwn.
Then timing and AFR
If you are still having problems get it on the dyno
 
#3 · (Edited)
That engine comes with an S&S 600, average compression is at 180 cold throttle open.. by your numbers it looks like someone has changed the cam to a smaller version,,, the 600 has 600 lift, and 260/265 duration,, sounds like you have around 250-255 cam in,,, this will seriously hinder the performance of the engine,,, or way to tell is pull the cam, and the grind # is on the inner end of the cam, if it is S&S... the downside is,,, many ignorant wannabe engine parts hangers,, think they need a torque cam,, in a 113,, lol that is just plain ignorant..

The right jet combo will be around a 33 low speed,, idle screw out 1-1,25 turns,,, acc pump just under 2 turns out from turned off,,, it has 4 turns adjustment.. idle set at 1000...
The cam can cause hard starting,, and smoke batteries and starters....
I had one come in a burger 113 S&S,,, the owned wanted releases,, I did a ccp test it was 250 psi,,, I talked him into letting me remove the cam, it had a cam that would have been great in a stock 80 incher,,, he was well pleased with the 600 cam and a tune... I always kept a couple 600's and a couple 640' on the shelf also,, the Andrew's EV82 AND EV 84 are awesome performers,,, but it needs at least 11-1 compression or more...
Exhaust can hinder performance above 4k rpm..
 
#4 ·
Ok I talked to s&s they said thats where it should be without compression reliefs and a 600 cam, they also said timing should be 30 to 32° btdc he said that would be 30° advanced, from what the timing light shows is 30° advanced is only 10° on the ignition module tic marks? If I adjust it 30° by the marks on the ignition it still runs good but I don't know if it's right
 
#5 ·
That is not right,,, adjusting by the timer plate is considered base timing,, usually about 8-10 degree advanced.. then the timing curves built into the module, or the timer plate, in the case of the all in 1 units,, brings the advance to the max value, at a specific rpm...
My personal 113,, a hotter version of the S&S 113,,, is set at 28 degrees total, with it coming in slowly to 4000 rpm.. with 8 degrees initial..
Every engine is a little different,,, what works for mine, probably will not work for you,,, mine has increased compression, a different cam,, and headwork,, plus pipes with stepped tubes,, the big engines are choked down by pipes made for the small engines,,, there are some of us here, who crank these big engines up, all the way through 6k+ rpm in high gear..

Just some food for thought,, when you run across issues that don't make sense..
 
#6 ·
Ok thanks I understand the timing now this is my first harley I've actually worked on I have several Japanese bikes and harleys just never had to really work on the harleys so learning as I go. And another question bike had a 76main jet and 31 intermediate it was running lean so I went to a .78 and .33 the bike runs best with the idle mix screw 1 turn out but I have to have the accelerator pump about 4.5 turns out for it not to hesitate when I blimp the throttle, leading me to think I need a bigger intermediate jet but with the idle screw only needing to be 1 turn out going up in a intermediate jet for the accelerator pump would contradict the idle mix screw right?
 
#9 ·
You should do away with the voes,,,, large performance engines do not need them,, and may be a partial source of throttle blip hesitation... I had about 30 or so,, large performance engine powered bikes I took care of for clients,,, 4.5 turns out on thepump, is .5 turns farther than it works... none of the bikes I take care of,, has a pump setting over 2 turns out...,
Your engine needs to be taken care of, by someone who knows more about the large engines than they do the small harley engines,, the timing isn't a multiplier, it is just a base setting to get it running then the ignition profile takes over,,, 30 degrees with 8 degree advance is 30 degrees when the program reaches it high value...
Every hi 4 ignition I have ever seen has been a problem, or failed years early I had 1 fail before I was finished tuning it,, set for single fire,,, it lasted maybe 4 minutes,,, yeah, they were all covered under warranty,, I had them credit my account, and bought dyna 2000I's.

Look up thunder jets by zippers performance,,, if you want that engine to survive check it out seriously. 2 circuits cannot feed the needs of a big S&S engine
 
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