A rider ...

[pd]

New crank seal is installed . Nice tight fit . I left the gasket in place behind the seal race for insurance against a leak there .

Ran the motor , but it quit , rather abruptly . I'll give you one single guess as to what happened .
I let it cool down and tried again . It ran , but begrudgingly .

I get to tear the top end off , again .

Before I do that , I need to do a pressure test . I think that may be the only thing that might tell me where the extra air is coming from .

Maybe I should just rebuild the motor completely . After 3 years of not having it run for more than a few minutes , countless times and hella bucks and time spent , it's likely wore out .

Pete .

[pd]

I pulled the motor this morning , in preparation for a pressure test . I removed the magneto , carb and exhaust .
I'll have to make blocks to seal the intake and exhaust before I can run the test .

The case looks like it's in very good condition . Smooth surfaces and no indication of cracks , anywhere .

Pete .

[pd]

Immersion pressure test results : Both intake and exhaust were the only points of leakage .

I used wooden blocks and cork gasket material to seal those ports .

Normally , a pressure test consists of sealing intake and exhaust , then applying 9 - 10 pounds of air which should be held for up to 10 minutes .

I didn't have a pressure gauge or the proper fittings to accomplish that .

I simply submerged the sealed motor ( less the magneto ) in a bucket of water and applied about forty - fifty pounds  of air through a spark plug hole . The air nozzle was sealed to the head via hand pressure and a straight rubber spark plug cap .
The leaks appeared almost immediately , which was expected and the object .
Even with higher pressures , I couldn't fine any other points of leakage .

So , I have to find a better way than what I have to seal both ports if I ever want to use this motor and have any kind of reliability.

I'm thinking about using insulator blocks in both places . Obviously , the exhaust block will have to withstand some very high temperatures . I might use 1/4" plate aluminum for that , unless I can come up with a better solution . 

Pete .

[ndian22]

I'd suggest copper. Rick C.

[pd]

I though about that , too , Rick .

Finding it around here might be the challenge .

Pete .

[ndian22]

Pete I purchase all my small quantity metals from ebay, copper, brass & odd ball aluminum. Search copper plate & you will find all manner of trim copper from thin sheet to really thick plate & in sizes like 12" x 12" - 4" x 6" etc. It's pricey per foot but really just chump change when compared to perhaps solving your long term 2 cycle problems. I openly confess not being knowledgeable about the Simplex engine, but I've built 6 or 7 double strokers over the last 3 or 4 years with mods ranging from mild to semi-wild & raced and built 2 & 4 cycle motors dating back to the 50's and have used copper exclusively for head gaskets & exhaust manifolds since the late sixties so I'm a believer. Copper may not solve all your current motor problems but properly fabricated and installed copper will insure you're motor won't leak at those critical points you've chosen to seal with it. Best luck, Rick C. 

[pd]

Ha . Just after I wrote that last post , I thought 'Ebay!!!' . Sure enough , I found something fairly close to what I think I need .

I agree about copper gaskets . I've been messing with motors since the late 50s & early 60s . I had my '72 H1 Kaw apart more times than I probably should have , trying for more , while drag racing . I tried aluminum but had better results from copper .

Maybe I should take heed from others experience and those early lessons .

Thanks Rick C , for your suggestion and the reminder .

Pete .

[OnaWingandaPrayer]

when I was a teen racing karts in a briggs/stratton 5HP class  I cut my head gaskets from a copper sheet . If I recall we annealed them so they were soft before installing them .

[pd]

when I was a teen racing karts in a briggs/stratton 5HP class  I cut my head gaskets from a copper sheet . If I recall we annealed them so they were soft before installing them .

I recall doing the same on my 500 .

I have to admit that I haven't had to use copper very much over the years , due to the advancements in gasket construction .

Pete .

[carryall]

   I've re-used/annealed copper head gaskets on a few occasions myself.  For leakdown/pressurization test, I've used expanding rubber boat plugs, and various sized frost plugs with a little adapting before.  I've never pressurized more than 20lbs tho.

[ndian22]

Copper plate sold on ebay is quite frequently listed as "dead soft" which will not require annealing in order to easily work the material.   Rick C.

[pd]

Just out of curiosity , has anyone tried annealing aluminum ?

Pete .

[ndian22]

Yes aluminum also goes soft for easier shaping. A torch can be used for a heat source. Books have been written dealing with the complexities so short answers are just that...incomplete. Knowing the type aluminum your annealing will allow you to go to the heat tables (charts) for the proper temperature required. Use a temperature stick to mark the metal for the easiest & quite accurate way to judge when the aluminum reaches that proper temp (it melts) and remove heat. Or you could just experiment, but I wouldn't recommend it, till you discover it's not worth it. Proper re-hardening of the metal is another matter

Unlike steel aluminum does color change so a range of temp sticks are handy to have on hand for ferrous and non ferrous metals...not just for annealing but also hardening. Case hardening steel surfaces with powder is another use for temp sticks.  Rick C.

[carryall]

You meant doesn't change color...I agree ndian22.   We worked with alot of different aluminum alloys at our shop for both structural, and ornamental applications.  The details involved for proper work annealing and what type rod works with what and how it reacts with things like anodizing sometimes seem more like witchcraft than metallurgy.  LOL.

[pd]

Hmm , so every time we fire our motors we're annealing any aluminum that's close enough to the heat ...

No wonder the exhaust manifold on my M was misshapen . I applied a bit of heat with a propane torch and was able to get it back into usable shape .

Pete .