K21 Deliveries

[Al Hobbs]

I believe I've caught up with everyone who has ordered a K21. The last four engines ordered are either in the amil or ready to mail.

Another box from Ukraine showed up today, so I should have an inventory on hand from now on.

My sincere thanks to everyone for the support they have shown the K21.

Al Hobbs

 

[FloridaScaleBoater]

The bearings in the K21 are the same size as the Mac, CMB 21 BETA & Valvola, correct?

 

[Buckshot]

The bearings in the K21 are the same size as the Mac, CMB 21 BETA & Valvola, correct?

Yes

 

[Tom David]

Hello Al,

If you’re coming to Atlanta Spring Nationals, can you bring me one of the K21 motors.
Will use turbo head button.
Need header and a couple of gaskets for header. Will not need collet.

Thanks,
Tom David

 

[Al Hobbs]

Hello Al,

If you’re coming to Atlanta Spring Nationals, can you bring me one of the K21 motors.
Will use turbo head button.
Need header and a couple of gaskets for header. Will not need collet.

Thanks,
Tom David

I will have engines and headers with me in Atlanta.

 

[Tom David]

I will have engines and headers with me in Atlanta.

Please put my name on a K21
Send me a measage for total cost and I will send check your way.
Thanks,
Tom

 

[Rodney Rogers]

Will they have the better bearings in them ? do they come with a header ? has the head been fixed ? is the cable collet 3/16? thanks

 

[Al Hobbs]

They come with standard, adequate bearings. If you are going to run hard, racing, time trials, I'd suggest you install the best bearings.
If you run for fun now and then the bearings in the engine will last quite a while if you take care of the engine.

A ten degree header is another $30.00 plus $3.00 for the seal.

The engine comes with two head buttons. One will be replaced at no charge. The other is for turbo plugs and it fits fine.

The cable collet that comes with the engine is for .150 cable. Srpeedmaster makes a collet for this engine to fit 3/16 and one to fit 3/16 square drive.

 

[Buckshot]

Will they have the better bearings in them ? do they come with a header ? has the head been fixed ? is the cable collet 3/16? thanks

I ran the test engine pretty hard with the bearings that it comes with and had no issues. The rod has not been modified, and it has had no issues. I installed new bearing in mine a week or so ago and it had ZERO end play, motor still ran great at the race last weekend.

 

[Terry Keeley]

I installed new bearing in mine a week or so ago and it had ZERO end play, motor still ran great at the race last weekend.

Is the front bearing tight in the case? Tight on the shaft?

Or both?

 

[Buckshot]

Is the front bearing tight in the case? Tight on the shaft?

Or both?

Not excessively. I think the big bearing pocket would need to be a few thou deeper to release some end play if desired, but so far I have not seen a need to do anything about the end play.
Bearing to case fit is nice and the crank fit in the races is good also.

 

[Tom Foley]

Any photos of the engine disassembled ?

 

[Terry Keeley]

Not excessively. I think the big bearing pocket would need to be a few thou deeper to release some end play if desired, but so far I have not seen a need to do anything about the end play.
Bearing to case fit is nice and the crank fit in the races is good also.

Are you sure the bearings are fully seated in their pockets?

 

[Al Hobbs]

Are you sure the bearings are fully seated in their pockets?

The big bearing is a snug fit on the crankshaft. Not so tight that you have to drive it on, but you can feel it is tight, not loose at all. This in itself will reduce the endplay a bit. I noticed that when Jim Allen was assembling the Nelson engines, he would drive the big bearings into place with a mallet and jig. I asked him if it was too tight. He wanted the bearing to spin without the crank slipping in the bearing inner race at all.

 

[Tim Kish]

Are you sure the bearings are fully seated in their pockets?

Perhaps the large bearing inner race I.D. has a larger radius on one side than the other and it's in backwards?
Seen that before.

 

[Buckshot]

Perhaps the large bearing inner race I.D. has a larger radius on one side than the other and it's in backwards?
Seen that before.

Now I’m curious!! Maybe also due to (2) different manufacturers!!
Full disclosure, when I changed bearings mentioned above, Al only sent the big bearing because he hadn’t received his full bearing shipment from WIB yet. So, I used an SKF small bearing in the interim.
I’m not gonna pull the motor apart right now because I don’t have any more replacement bearings here now but when I get more this will be high on the radar!
Thanks Tim!

 

[Mike Hughes]

Buck,
Dig the old ones out of the can for comparison.
Mike

 

[Buckshot]

Buck,
Dig the old ones out of the can for comparison.
Mike

Actually still have them on the bench. Was thinking about taking them apart to see what the balls and races look like.
Radius’ look the same on both sides.

 

[Al Hobbs]

Actually still have them on the bench. Was thinking about taking them apart to see what the balls and races look like.
Radius’ look the same on both sides.
View attachment 324464View attachment 324465View attachment 324466

Those used bearings look good for more than 4 gallons of fuel.

 

[Terry Keeley]

Do they have a brand name on them? Steel cage? Tabbed or riveted?

Are you sure the bearings are fully seated in their pockets?