Author Topic: cold cranking compression  (Read 677 times)

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Offline joe40x

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cold cranking compression
« on: February 07, 2018, 05:47:39 PM »
How much ccc is to much in a twin cam? 200? 205? 210? Assuming 93 octane and a good tune. 103 cu

Offline Latrobedyna

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Re: cold cranking compression
« Reply #1 on: February 07, 2018, 09:01:28 PM »
I am run 209 / 206 in a 95" with no problem's. My brother is running almost identical numbers in his 107 same thing runs good . But we both had to put in compression releases.
2006 FXDB , 95" 57H +4% cam, 10:25 pistons: Ported head's. Lots a fun

Offline rhuff

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Re: cold cranking compression
« Reply #2 on: February 07, 2018, 09:58:31 PM »
I'm around 205ish with a great tune and only 91 octane available.  I personally don't want any more.  I'm at 1700 elevation in Las Vegas, but this will be my first summer here.  Guessing I'll have some starting issues and maybe some minor pinging.  Last fall, when in Death Valley (zero elevation getting gas), old girl had to sit 10 mins before I could get her going again.  Probably time for a 1.4KW or bigger starter. 

Offline 1FSTRK

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Re: cold cranking compression
« Reply #3 on: February 08, 2018, 04:23:31 AM »
A couple things to note

You should be doing a proper CCP test when checking Cylinder Cranking Pressure, your cold numbers can and will vary and be deceiving.

The year and model of the bike is relevant when it comes to starting and running trouble free.

Touring bikes have bigger batteries compared to Dynas and Softails.

Softails have batteries that are subjected to much higher heat than Dynas

07-18 have a different primary ratio and transmission compared to the 99-06 bikes this effects both starter ratio and gearing load on the engine when riding.

Carb bikes are both Carb brand dependent and Ignition brand dependent and even with the best of both are just not as tune controllable as EFI.

EFI bikes are tuner brand dependent as well as dependent on the ability of the person doing the tune.

Does it have compression releases

What fuel is available

Type of riding and weight
 
So the simple answer is, it is not that simple.
Many times people see a compression ratio or CCP number on a good running bike and then try it for themselves only to have terrible results. Just like everything on these bikes it is the combination that makes it all work.



Offline ghillman

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Re: cold cranking compression
« Reply #4 on: February 08, 2018, 06:57:01 AM »
How much ccc is to much in a twin cam? 200? 205? 210? Assuming 93 octane and a good tune. 103 cu

I'm at 209, ran 91 when I had to, no issues. There is no substitute for a good professional tune !. Good tuner can really help out in that area

Offline No Cents

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Re: cold cranking compression
« Reply #5 on: February 08, 2018, 07:04:39 AM »
   If memory serves me right a factory CVO 110 with the factory 255 cams cranks right around 225 ccp's. That's about the highest I would want to see for a street ridden bike. Somewhere in the 190- 205 range is right on target for me.
08 FLHX 124", wfolarry 110 heads, CR630i cams, Burns pipe, 158/152 sae

Online harpwrench

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Re: cold cranking compression
« Reply #6 on: February 08, 2018, 07:34:48 AM »
So what is the standard procedure temp wise? Run it 20 seconds to pump up the lifters, or longer to get to a standard temp? My 103 cranks 205/200 with the first test, and 220/215 at operating temperature.

Offline 1FSTRK

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Re: cold cranking compression
« Reply #7 on: February 08, 2018, 12:52:58 PM »
So what is the standard procedure temp wise? Run it 20 seconds to pump up the lifters, or longer to get to a standard temp? My 103 cranks 205/200 with the first test, and 220/215 at operating temperature.

OEM manuals and compression tester instructions almost always use the term warm. When I have seen a number in degrees it has varied from 120-180F. I was taught to start the engine and warm up to the temp then do the test rather than starting hot and letting it cool to the test temp. Many thing is to establish base numbers and always test the same.

Online les

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Re: cold cranking compression
« Reply #8 on: February 08, 2018, 01:34:07 PM »
So what is the standard procedure temp wise? Run it 20 seconds to pump up the lifters, or longer to get to a standard temp? My 103 cranks 205/200 with the first test, and 220/215 at operating temperature.

Yep, the cold and hot numbers vary about that much.  I always do both, which provides me a little bit more information about the engine.

Offline 1FSTRK

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Re: cold cranking compression
« Reply #9 on: February 08, 2018, 01:44:29 PM »
So what is the standard procedure temp wise? Run it 20 seconds to pump up the lifters, or longer to get to a standard temp? My 103 cranks 205/200 with the first test, and 220/215 at operating temperature.

Yep, the cold and hot numbers vary about that much.  I always do both, which provides me a little bit more information about the engine.

les when you say cold do you mean an engine that has not been run before the test, like over night maybe?

Online harpwrench

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Re: cold cranking compression
« Reply #10 on: February 08, 2018, 02:19:55 PM »
 :up:

Offline itsafatboy

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Re: cold cranking compression
« Reply #11 on: February 18, 2018, 06:00:29 PM »
i run 210 in a 116" its fine , just have to hold the rear compression relief open when starting , probably dont but rather do that then break a ring gear,  been there done that now have a 9/66 tooth it will not break haha 

Online les

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Re: cold cranking compression
« Reply #12 on: February 18, 2018, 09:14:21 PM »
So what is the standard procedure temp wise? Run it 20 seconds to pump up the lifters, or longer to get to a standard temp? My 103 cranks 205/200 with the first test, and 220/215 at operating temperature.

Yep, the cold and hot numbers vary about that much.  I always do both, which provides me a little bit more information about the engine.

les when you say cold do you mean an engine that has not been run before the test, like over night maybe?

Yes.  So if you do a cranking compression test as soon as you walk up to your bike (stone cold overnight) then run it to get it hot and do another cranking compression test, the numbers will be totally different.  I like to do both because to me it helps give me more information. 

Offline 1FSTRK

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Re: cold cranking compression
« Reply #13 on: Yesterday at 01:07:37 PM »
So what is the standard procedure temp wise? Run it 20 seconds to pump up the lifters, or longer to get to a standard temp? My 103 cranks 205/200 with the first test, and 220/215 at operating temperature.

Yep, the cold and hot numbers vary about that much.  I always do both, which provides me a little bit more information about the engine.

les when you say cold do you mean an engine that has not been run before the test, like over night maybe?

Yes.  So if you do a cranking compression test as soon as you walk up to your bike (stone cold overnight) then run it to get it hot and do another cranking compression test, the numbers will be totally different.  I like to do both because to me it helps give me more information.

Thanks les, I am sure you have that figured out, I would just caution people reading on the forum that cold tests can be very misleading for us DIY guys because of cold oil and lifter pump up rates. Some false highs because of less duration and other reads differ with which cold cylinder you pump first.

Offline joe40x

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Re: cold cranking compression
« Reply #14 on: Yesterday at 01:51:43 PM »
Thanks for the replies guys. I guess i'll be safe  with a good tune and 93 octane at 210?

Offline Rockout Rocker Products

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Re: cold cranking compression
« Reply #15 on: Yesterday at 02:35:57 PM »
My drop in 110 cranks about 225-228. Had to take some timing out but it seems to run strong. Tman 590 cam was supposed to drop CCP from my 57 but didn't change a thing  :idunno:
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Offline Ancient

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Re: cold cranking compression
« Reply #16 on: Yesterday at 02:44:45 PM »
My 103 with 57's and a little extra squish cranks 212/212 on my old Milton gauge. The gauge dates from the Nixon administration so who knows how accurate it still is. :nix:
Greg

Offline Scott P

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Re: cold cranking compression
« Reply #17 on: Today at 04:08:06 AM »
200 psi ccp is a nice area to stay at, for an EFI bike.
Peel that back a bit for a carbed machine.
Otto Knowbetter sez, '"Don't mistake kindness, for weakness".