Engine selection video and replacement bearings.

Thanks for sharing the breakdown on the engine numbers, I've been confused with the options myself. I called a dealer about moutning the engine by the sump cover face and they were to call me back, surprise, they didn't. Looks like some of the direct drive people in europe are mounting the engine that way when it's on the firewall side.

I'm trying to keep these bearing thoughts in a logical order. I need to start out with a couple questions.

Is there any type of keeper on the sump cover to hold the bearings into the bore?

What is the bearing in the other end of the motor?

Thrust loads are present, probably minimal, certainly not dominant.

First off the crank shaft has an end play spec. This implies that the bearing on each end is responsible for thrust in it's direction.

Thrust bearings from page 114. Absolutely not. These bearings will take no radial loads. All of the power production and rotating mass loads are radial. The engine will probably not survive past startup.

Page 118. Same as above.

Page 120. Same as above, plus now you would have to also capture the outer and inner race in both directions.

Page 122. same as 118 and above, but also has a provision to take up misalignment.

Page 138. Roller bearings. Not the worst idea ever, but don't accept axial loads. They have a tolerance on how much axial play they can handle. If the other end of the crank can only take thrust loads in one direction, then this bearing will be destroyed. This bearing is very strong at radial loads.

Page 243 and 244. Single row taper roller bearing. Radial loads create axial loads in this bearing.
Double row taper roller bearing. This bearing can work. Is it 1 piece or 2? If 2 it requires serious clamping forces to keep the inner and outer races together. I've installed a $100K of these over my life, matched sets of 4 bearings wide with zero endplay. They'll take lots of pressure in axial and radial loads. Not what I would call a high speed bearing. This would be a good prop bearing IMO if provided with an oil flow.

I'm 99.9% sure Briggs used a deep groove ball bearing here. It will accept good radial loads, and a decent amount of axial loads. It doesn't need captured in all directions as it doesn't turn radial loads into axial loads, so the inner race against a shoulder on the crank and the outer race in the sump cover bore is all the is needed.

As far as speed. Briggs has a lot of numbers we don't know. Bearing calculations when it comes to heat/lube/loads is complicated. My honest opinion is they have more resources to make a better decision than I do. They must have caught an issue with the single bearing and doubled it, my gut feeling is that if they doubled marginal in some situations, it's good now.

I will post more details later, but yes, the 6007 (3tm6007/p64 marked on bearing) is indeed a deep groove ball bearing and after my review of internet it is probably the correct choice, I will respond to your stuff in more detail later cause I have a water leak underground I am repairing today

In my understanding Europe doesn't have the speed limitations we do, so a shorter higher RPM prop probably is fine for them.

Sounds like I got an okay to mount the engine with the large bolt circle on the sump cover. Now to sit down for a few hours and see if I can integrate the redrive and the engine mount. I'd feel so much better about all that, and should be a wash in total weight. If I get something decent, I'll contact Ace about selling a stripped down version without the mount. Another reason the starter has to go.

Looks like 386447-0090-G1 is the cheapest engine part number, and looks to have dual bearings. I think having the dual bearings is probably a must.

i agree on the bolt circle, i am thinking of L shaping the motor mount to rise in front so the redrive pulls on the motor mount.

I'm 99.9% sure Briggs used a deep groove ball bearing here. It will accept good radial loads, and a decent amount of axial loads. It doesn't need captured in all directions as it doesn't turn radial loads into axial loads, so the inner race against a shoulder on the crank and the outer race in the sump cover bore is all the is needed.

As far as speed. Briggs has a lot of numbers we don't know. Bearing calculations when it comes to heat/lube/loads is complicated. My honest opinion is they have more resources to make a better decision than I do. They must have caught an issue with the single bearing and doubled it, my gut feeling is that if they doubled marginal in some situations, it's good now.

I agree with this, after reviewing all the bearing types, the deep groove ball bearing is the way to go, so really the only issue is to review those that are available to find the one that is best. I can't find manufacturer specs on the stock one so I am looking at all manufacturers that provide specs for it.