dmech

J 160 ,wet wings. Engine looks like a g4 maybe

Mate, I been engine reconditioning for 47 yrs I've used a lot of mahle pistons, been to many seminars conducted by them per invite from my suppliers. I think you just being the ostrich here

Have seen a few sl and ci piston failures Breaking etc over my 47 Yr in engine reconditioning usually this was addressed by the manufactura or after market. ACL made pistons oem for local vehicle makers. I to have made hyperutectic pistons with slots for race engine that took out to state titles over 2 yrs this was running up 7000 rpm 32 laps, absolutely no probls with pistons. Also another s 6 sedan 2 state titles same engine all of shelf ordinary Rd parts used ACL duralite 060" no speed shop parts used in this engine mod cam ground to my specs by camshaft engineering as that was the only maching that I farmed out. Also a lot ofst stock and modified sedan engines for others all very competitive. I had a datsun 1600 st stock that took out over all points at our club for 3 consecutive yrs this engine was running ACL slotted pistons and often ran up to 9000rpm, yes I did have some valve failures but was able to eliminate them. This car also took out the Brian rose memorial for 2 consecutive yrs ,this car was the smallest engine , competing against 3300cc holden toranas. So I to have had plenty of experience with pistons and I do know what causes the cast piston to break in the jab I have also seen solid slots break and seize in the jab as well, and even one early gen 1 ACL piston which was the only one I had to discard the crank case and 2 con rods also camshaft and some followers. You say you have made pistons,please tell us here on the forum how you would design a piston for the jab ie; material heat treatment cam on skirt skirt type that would fit in jab engine clearance periphery , skirt surface Finnish for the steel n Barrels , taper on skirt, tell us what you know!! Adrian

Ihabe informed glen rf guy of company to get pistons and part numbers. He has since posted pics which have part number on them, check his earlier post

Can't see mahle written on it. Can you provide more detailed pics similar to how glen posted earlier. How about part number may be it will fit the jab , not sure where I will find an injector to suit. BTW it is for Ci engine. But could just throw it in and see, at least that will be more than what happens on forums Adrian

OK nev I agree cast is ok and slotted piston of right design more than adequate. The jab one can be modified To work. If you know pistons , you should be able to work out the problem, it stocks out like dogs balls. You say cast ok, I say to you stop talking about it and find one, or show us a design that WILL Work! I have a modified jab slotted skirt piston 4 of, any one care to try it , do the test under the prolonged worst conditions.. At the Monment we have the mahles straight off the shelf and if fitted correctly with the right rings work well, we have 2 engines that reached 2000 hrs under about the worst conditions and still going good, they more than likely go on for another1000 hrs , however the engine is mandated for complete rebuild at 2000 hrs Adrian

I did inform glen where to get pistons from, and he has progressed from there. These pistons have been available in australia for years.

Forged pistons, so your saying that these won't work in jab engine. I can tell you that the marles that I have fitted have done more than2 thousand hrs in a flying school a craft , this is the same set and there are two other planes getting close to the same hrs, without any problems. We have approx 15 a craft flying successfully with mahles fitted including mine. I have done the hard work and expense to do the necessary engineering to make these work in the jab engine. The trouble with forums there is a lot of hypothetical theories, and arm chair engineers.i have done the engineering and trials and testing with the help of a flying school , about the hardiest test available and this has been on going since 2018. I don't want to hear of people throwing mahle pistons in there planes and then getting on these forums bagging them because they have experienced expensive problems . I was advising glen of our successful use of these pistons by email and pm,s. And don't appreciate it being put on forums At this stage all info I gave to him was for his own use on his a craft. Adrian

just out of interest, it seems that no one actually said or explained what was going on and causing the starter run on. it looks to me after looking at solenoid connections that it was in a latching mode. automotive solenoids often have an extra primary terminal as well as the button terminal , the first terminal goes hot + when the solenoid is activated, this provided to bypass the coil ballast resistor only when starting the engine in certain vehicles, since the diode was connected across these two terminals and if diode was connected wrong way around or shorted it would cause a latching event, which would require the battery to be disconnected to un latch the solenoid. Anyway glad to see it got sorted out

what has happened to the old classifieds , will they return?

Hi nev what do you think of those specs I gave you?. Would like to hear your comment

Hi nev, got some measurements from an old barrel wear marks yesterday from a gen3 jab piston exits the barrel spigots by 20.12 mm [792"]. Piston we are using exits by [ .204" ] measured from bottom of oil groove . Skirt engagement of jab piston 25.9mm [ 1.019"], piston we are using 31.5mm [1.241"] [ oil ring groove higher up] all measurements are at bdc . the piston we are using is a light weight forged piston with a more resilient material , strong as, but comes with its own set of problems as well, but at least no breakups after a 1000 hrs and inspection indicates they could be used again. dmech.

nev I will look at measurements on piston over the week end. High sill and flex does work if their working environment is engineered correctly , as it does in the holden v6 ,However not in a jab. You might say the same about high carbon steel and flex, like valve springs for instance , set them up wrong and they break to. The pistons are designed to flex but they have limitations , like most things metal. The piston does come a considerable way out of the cyl. spigots as you suggest, however there is very little angle load as it is bdc . I and others here ,are using a different piston to the jab, whi we are using different pistons , not sure how they would go on the jab pistons , we had these made in the u.s and quiet expensive , but worth every cent I reckon. ch is lower sill. content .about 10% the jab piston is hyper sill content and hardened to t6 t5 would be better which is what acl used to use. However a small mod to the present pistons will sort the cracking problem.

Thank's for info one-track, just an article I read inside a dc3 on display at the Mareeba air port QLD. Was just outside a repair facility there . That was 15 yrs ago.

I read some where , I think it was at Mareeba airport, that the Russians copied and made more dc3 s than the original manufacturer never paid a cent for license or copyright .