leak down and leak down tester?'s

[cam2]

i was wondering how many of you do a leak down test after rebuilding your engine? if you do, what setup do you use? i did some searching and the kits that i've found on-line were crazy money, although cheaper than rebuilding the engine again if a leak was present. i'm sure i could piece one together, so i was hoping to get some info from you guys on what parts to use and where to buy them in order to save me a bunch of trips to ten different stores. or maybe you know where to get one at a decent price. one local shop said that they charge $60 dollars to do a LD test, but i think that i could make one for that price. at least i hope i can.

[RNBRAD]

LINK

[cam2]

LINK

thanks Brad, that' what i was looking for. i did a search on here but i didn't search that far back in time.

[dajogejr]

CAM2,

PM Machwon on this board, his name is Bob of R&B racing out of Michigan.

 

True, you can build your own from hardware parts, but he sells a kit ready to use and has done all the legwork for you for about 20 bucks or so more than you can drive around and buy the parts yourself.

 

Bob is a helluva nice guy, send him a PM....they're really not that expensive. I wanna say 50 bucks or so, but...don't quote me 100% on that.

 

Good luck!

[cam2]

LINK

brad, does it matter what position the pistons are in? also, is it important to have a reed petal open on the pressure gauge side? i'm sure if there was a major leak you would notice a drop in pressure, but if you had a slow leak it would seem that "maybe" there may be enough chamber pressure to keep the reed petals closed which wouldn't show much of a drop in pressure. maybe not, but i'm wondering if it's possible.

Edited November 6, 2006 by cam2

[dajogejr]

brad, does it matter what position the pistons are in? also, is it important to have a reed petal open on the pressure gauge side? i'm sure if there was a major leak you would notice a drop in pressure, but if you had a slow leak it would seem that "maybe" there may be enough chamber pressure to keep the reed petals closed which wouldn't show much of a drop in pressure. maybe not, but i'm wondering if it's possible.

 

Reeds can be partially open....they usually don't completely seal and have a small gap when the motor is not running.

 

You're really testing the crank seals, intake seals, base and head gasket....and case halves in the crankcase itself....

 

Reed petals won't seal completely unless the back pressure from the engine is had from it running....

[RNBRAD]

brad, in the second pic in the link i noticed that there is a nipple on the side of the plug that goes into the intake manifold. is this used to keep the reed petal open? also, does it matter what position the pistons are?

 

No, the nipple is just the plastic reduction coupler where I hook the hand pump to. It doesn't touch the reeds. The reeds won't make an air tight seal. Also just rotate your flywheel a couple times once you have the engine pressurized to 6lbs.

[cam2]

Brad thanks for the tips. the only thing i forgot to do was rotate the flywheel, although i did put the pistons as close to the center of the stroke as possible. the engine held 6psi steady for over 8 minutes without any signs of losing pressure, according to the gauge. my setup cost less than $20 plus a few odds and ends that i already had. here's a pic of my hoakie setup.