LegendsRacer - Legends & Bandolero Racing Forum

BANDOLEROS => Engine Care & Tuning => Topic started by: ba/thejafan on November 09, 2009, 09:44:28 pm

Title: Engine compression and leak down
Post by: ba/thejafan on November 09, 2009, 09:44:28 pm

Does any one have #s that are acceptable for compression and leak down. Can check both but not sure if engine needs to be warm first for either or both before checking.

Thanks for all input.

Title: Re: Engine compression and leak down
Post by: IraceLegends77 on November 10, 2009, 10:30:29 am

The engine defiantly needs to be warm for the compression check. Also make sure the throttle is wide open too. Compression depends on if you are talking open motor or sealed. Open can only be 165lbs. and I think that the limit for sealed is 190lbs. but you will never see that #. I really can’t help with the leak down. I know someone on here can.

Scott

Title: Re: Engine compression and leak down
Post by: VMS Motorsports on November 10, 2009, 10:34:32 am

Depends on what you mean by "acceptable" A lot of different builders have idea on what they think is better as far as overlap and such. Are you looking for the factory specs, or trade secrets?  ;D

Title: Re: Engine compression and leak down
Post by: ba/thejafan on November 10, 2009, 12:28:33 pm

I  just got done doing these, so I have #s, I guess I am trying to figure out if it needs rebuilt or not.  So if you have acceptable #s, factory spec, or "hot tip" I would take any of the 3 or all if possible

Thanks

Title: Re: Engine compression and leak down
Post by: justfreaky on November 11, 2009, 09:22:41 pm

I did not see any compression numbers in the rules for the Bando engines. Granted. I only did a quick scan of the rule book. I'm still learning about the Bando stuff; So am interested in the info. I believe the 165# is for the Legends cars.

Steve

Title: Re: Engine compression and leak down
Post by: Magic Man on May 10, 2010, 05:00:17 pm

I am curious as well, I am curious whether we need to ship this engine off for a rebuild but want to compression check it first, but I wont know what the numbers tell me.....

Title: Re: Engine compression and leak down
Post by: justfreaky on May 10, 2010, 08:31:32 pm

Since this thread is from November of last year, and no one has shared any numbers with us... Nobody really knows, or, they are just unwilling to share.
I would think compression would still be tested with the engine cold.
Maybe Ed could enlighten us. Perhaps Tristan can get a reading off his new engine and let us know.

Steve

Title: Re: Engine compression and leak down
Post by: bandostuff.com on May 10, 2010, 10:12:19 pm

I have only checked compression on one bando engine  and it was 175#.  As mentioned above be sure the throttle is wide open, that makes a big difference.  The engine warm is a good thing..

I have been using leak down lately and found interesting results.  I had an engine with 4 races leaking 29% and 30% through the intake valves.  Sent it to 600 for a valve job and got it down to 9%.  Had another engine that leaked 30% out the intake and it ran the same as the repaired engine when it returned.  There must be a story here but I haven't figured it out yet. 

I have yet another engine that was rebuilt and run since the dark ages, it leaks 8%.

If you use leak down and find leakage through the valves, tap the rocker arm.  If there is a piece of carbon or dirt between the valve and seat this will dislodge it improving the leakage considerably.

Title: Re: Engine compression and leak down
Post by: justfreaky on May 10, 2010, 10:20:57 pm

Thank You for the information Ed!
Good stuff to know.  ;)

Steve