Glow Engines Discuss RC glow engines

Saito 80 GK blown up

Old 11-14-2008, 10:57 PM
Join Date: Jan 2002
Location: Hesperia Michigan, MI
Posts: 12,957
Received 4 Likes on 4 Posts
Default RE: Saito 80 GK blown up

ORIGINAL: gkamysz

ORIGINAL: rcdude7

I just put new bearings in a saito 150 and I guess the front bearing seated slightly deeper than the orignal because I now have rod contact with the backplate. I took care of that clearance problem with a pnumatic die grinder w/sanding disk on the backplate. No more interferance problem!

That's an odd defect. You're positive the rear bearing was fully seated? I mean the parts are made to a certain size. If the bore for the front bearing was too deep, it should have been rejected before assembly. That problem just doesn't sound right. Either the bearings or the crank weren't seated correctly.

I had an NIB OS FS-26 that rubbed the backplate. It turned out the crank was an unusually tight fit in the bearings and wasn't fully seated.
Did you measure the width of old and new bearings with a micrometer? Capt,n
Old 11-14-2008, 11:30 PM
Senior Member
DarZeelon's Avatar
Join Date: Apr 2003
Location: Rosh-HaAyin, ISRAEL
Posts: 8,913
Likes: 0
Received 2 Likes on 2 Posts
Default RE: Saito 80 GK blown up

ORIGINAL: captinjohn

Did you measure the width of old and new bearings with a micrometer?
Bearings with identical inner and outer dimensions can have different widths.

For example, early MVVS .61 engines used the 16002 rear bearing (32x15x8 mm).
Later MVVS big-block engines (.61, .77 and .91) now all use the 6002 rear bearing (32x15x9 mm)...

The inner and outer diameters are identical, but not the thickness...
The later, wider bearing has a 30% higher dynamic load rating, to withstand the higher loads imposed upon it by the larger .77 and .91 displacements.

But if you happen to own an older MVVS .61 that has worn its bearings out (that will be the day...), please note that the rear bearing will not fit into the crankcase...

...Neither will the new front bearing, but it has 1 mm larger diameters and the same thickness...
Old 11-20-2008, 11:17 PM
Thread Starter
My Feedback: (61)
Join Date: Apr 2002
Location: Wolfforth TX
Posts: 280
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Saito 80 GK blown up

Just an up-date for you on this engine of mine. I recieved the new connecting rod from my LHS today. and the new rod does not have the bronze bushing in it, as the original equipment had. and seems to be a lot thicker on the bottom end. I am guessing this is because it is not bored for the bushing. all went back together in just minutes, and I never had to pull the piston out of the bore. just slid it out far enought to get the wrist pin and teflon buttons back in place. oiled it up good as I went and adjusted the valve lash. Great compression and smooth operation again..

Thanks for all the guys that tried to answer, and to those that got off subject a little, this is a great forum on a great site.

Old 11-20-2008, 11:55 PM
My Feedback: (16)
w8ye's Avatar
Join Date: Dec 2001
Location: Shelby, OH
Posts: 37,576
Received 9 Likes on 9 Posts
Default RE: Saito 80 GK blown up

Good job
Old 11-21-2008, 08:13 AM
Senior Member
Join Date: Nov 2005
Location: New Port Richey, FL
Posts: 2,568
Likes: 0
Received 2 Likes on 2 Posts
Default RE: Saito 80 GK blown up



Dar, here is my pre 1990 .80GK, it does have a bronze bushing and I believe my circa 1991 1.50 also has a bushed rod, I think they are the only ones I have with bushings.
I see where there has been rust?
The "rust",if that is what it is on the balance of the crankshaft, looks just like my New Saito 120(pictures in another thread in this forum). After less than six months and probably 20 reasonably short flights, my crank looks just like the one in post #14 above.

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.