Dear RC Groups:

The PIPE Here - perhaps no one else has thought of the idea, OR it might have been passed over at some earlier time...

...could there be a "sticky post" for a readily available list of the exhaust port threading specifications, for as many past AND present four stroke model engines as possible, here at RCGroups' "Engines" thread ??

Many people get used four stroke engines for their needs (instead of new ones), and it certainly seems that with four stroke engines apparently lasting longer than most of their similar sized two stroke competitors, a list of exhaust port thread specs for as many of OS's, Enya's, Saito's, Thunder Tiger, YS and other well-known brands of four stroke model engines from the past and present as possible, would help in finding exhaust system components for the older mills, that just might have the same exact exhaust thread specification as a newer engine that's still in production, or has readily available exhaust system parts on the market, even from "third party" sources that are not engine manufacturers themselves.

Some time ago I was in that potential situation with my own, 1983-vintage OS FS-90 rear camshaft four stroke mill...thankfully, a visit to my LHS (that just happens to be a Great Planes stocked store) had an OS FS-91 Surpass mill in stock complete with muffler, and the M11 x 0.75mm pitch exhaust port thread shared by BOTH engines allowed each other's exhaust components to easily and exactly fit.

A "starter" list of exhaust port thread specs for Saito four stroke owners DOES exist at http://saito-engines.info/mufflers.html , but I don't know of ANY other such list as yet, for four stroke mills' exhaust threading, for other brands of four stroke engines...

...hence the "sticky request" for that listing here at RCGroups, to help my fellow four stroke flyers.

Thanks in advance and Yours Sincerely,

The PIPE....!!

Great idea. Cost of OS muffler verses a Magnum muffler are very differnt and yet are probably compatible. It would make a nice and easy look up for the users.

I have a bunch of this info. I'll put it together and post it on my site. It's hard to confirm though without actually owning some engines as you find conflicting data.

Greg

Dear Chip01 & Gkamysz:

The PIPE here again...and there's LOTS of four-stroke mills - new and old, single, twin AND multi-jug, of all sorts of sizes and configurations, that could be on that list...!!

Some of us even like to make our own exhaust setups, and for RC Scale & Giant Scale models, that can really lead to some 'inventiveness', depending on the need and available resources.

For us here in North America, it MIGHT be a good idea to locate a place that would have a myriad of different METRIC taps & dies to help make our own properly threaded exhaust parts to use with our mills, and at http://www.newsontool.com/site_map.html there's the website of an Ontario-located threading tool vendor that seems to be loaded with quite a variety of metric threading tools to craft such custom four-stroke exhaust components with.

Here's hoping that there can be a good amount of quite useful info to come within this thread, that could help save some serious worry on finding just WHAT is out there for exhaust accessories for our four stroke mills...it's hopefully, just the start of a very informative thread.

Thanks in advance and Yours Sincerely,

The PIPE....!!

If you follow the Saito site to MAC and other supplers you can make a list of Exaust pipe dimentions. John Sard

On my page. http://www.dieselrc.com/download/

Greg

Is the chart any good?

Greg

The chart is great. I've added it to my bookmarks.
Do you still sell the cam bearing puller? I don't see it on your site. I work on engines for my club all the time and would like to buy one.

Lane

I have not offered the cam puller yet. I thought I could make it in a reasonable time on my manual lathe, but that wasn't the case. Outsourcing just a small number wasn't practical either. Now, though I'm working on a small CNC lathe, so I'll be looking at the pullers in a month or so to make a few.

Greg

I will check your site from time to time for the puller, thanks.
Lane

Originally Posted by gkamysz

Is the chart any good?

Greg

I am afraid something happen to it, when I went to it it was a HTML page but was labeled fs_threads.pdf .

I fixed it.

Thanks

Originally Posted by gkamysz

I have not offered the cam puller yet. I thought I could make it in a reasonable time on my manual lathe, but that wasn't the case. Outsourcing just a small number wasn't practical either. Now, though I'm working on a small CNC lathe, so I'll be looking at the pullers in a month or so to make a few.

Greg

Hi Greg,

I too would be interested in one of your cam bearing pullers, as would many others, I'm sure. Please let us know if you have any progress on this front.

Regards,


James.

I did build a prototype of a new design of the puller. It has been working well so I'll have a look at making them again. Unfortunately, the progress on the lathe hasn't gone far. I will get back to it this month.

Greg