Datsun Roadster Forum-311s.org

Hopefully someone can help me out with a problem I have here.

I have a 1967.5 1600 I'm rebuilding. Have had the crank turned to .010 under and purchased new bearings from Les at Classic Datsun.

I installed the bearings and when I went to place the crank into the bearings I found the center flanged bearing is wider than the space between the lobes. There is a .010 to .020 interference best I can measure with calipers. What is going on here? Are the bearings incorrect or should the Crank have been machined for some reason?

They are NDC bearings : MS-1042GP. Looking them up, the catalog says it is correct for a U20 motor in this year.

Any help would be appreciated.

Well, if the bearings say they are correct for a U20, and you have an R16 - sounds like the bearings are wrong to me.
BTW Welcome to the forum, post some pictures!

Sorry, I had U20 on my mind. I meant H20.

I have had thei prob before. i think the crank grinder didn't grind the thrust part of the main journal.

I would take the crank and bearings back to the machine shop and have them fix the crank.

What Kevin said. "Undersize" bearings are actually thicker than std. bearings not only in the journal, but also in the thrust. When a crank is ground .010/.020 etc, the thrust area should be widened an equal amount.

Mark

Thank you Kevin and Mark,

that is what I was thinking but never heard of this being to the crank. I'm a VW guy just starting on this Datsun stuff and I like it but there are a few differences I need to get used too.

Thank you very much for the suggestion.

hi everyone!

I'm also planning on building a r16 stroker.
I have purchased the crank below from a h20
http://vi.vipr.ebaydesc.com/ws/eBayISAP ... cureDesc=0

the mains are turned down 0.25mm and the conrods 0.5mm.

I asked him about the main bearings and his answer was:
There are 2 different types of main bearings, other than the thrust main bearing, I need to know the width of the the main bearing.
Have you got 8 pieces that are 19mm wide or 4 pieces that are 28mm wide and the other 4 that are 22mm wide

Anyone knows the answer? I'm still fairly new to the r16 engines...
And have no engine yet to rebuild since my original in use is a 3 main bearing
Thanks!

Do you need a 5 main block?

.010 on a thrust bearing side travel isn't that bad
Lots of engines have way more thrust clearence than specs and work ok ...I've seen 1/8"and no problems on Chevy's
Assemble it the crank ..then you need a dial caliper gauge on a fixture on the block to accurately measure the play ....running a stiff pp plate the main cause of wear ...your not going to find a thrust shim to fix it

I misunderstood the situation , always best to let the machine shop. Supply the bearings or you let them have them to check with

Usually the thrust surface on the flywheel side is worn on R16/H20/U20 cranks. If necessary, it should be surfaced. The bearing is normally "fit" to the crankshaft. King bearing offers several "standard" oversize thrust sizes, i.e. .010, .020, ...., if you don't want to fit and have your grinder supply a oversize thrust grind.

I suggest not having too much thrust clearance because it causes the U20 lower/R16-H20 only timing chain to wear much more quickly.

spl310 wrote: Fri Nov 20, 2020 10:06 am Do you need a 5 main block?

Do you ship to Belgium?

I know a guy who has a H20 forklift engine laying around.
So I'm trying to convince him to sell it to me!
That would be hopfully cheaper!.

If you pay for the packaging and shipping, yes

Or you can buy a 1500 crank and connecting rods and build a 1800cc stroker

That was the other option.