F4R engine clearance

[Radugns]

Since this information is not on each topic, I try to make a small table to can help us when check or rebuild or 172 or 182 engines.

I read some manuals from renault, but really could not find main bearings clearance and also find two values for rod bearings. Have someone any additional info to complete the table?

Thanks

 

[bozothenutter]

collate and sticky this in the guides section?

 

[Radugns]

After another research, I think for Big end is 0.02 - 0.07mm and for main a little bigger clearance, 0.04 - 0.075 mm. But NO SURE, please some confirm this. I find both values for big end, but there should be a mistake.

Also, for the piston ring clock, manual says 120 degrees for compression and sealing, and 120 degrees for oil scraper. Also, Wossner suggest to use 180 degrees on everything, and you can start from a valve pocket to diagonal. This way there is no gap on the wrist pin.

 

[Radugns]

I think this is the correct form:

From other f4r builder here, the "best" clearance for oe specs on the bearings is 0.035 (~1.5 thou) on rod bearings and 0.05 (~2 thou) on main bearings.
Also, each time when you rebuild and engine get quality parts, better to use oem for engine refresh and always new oil pump. The idea is to make an engine that will last "forever".
If there is anything I can help you regarding engine parts, pm me. I think I have lot of stuff to share.

 

[FrogJam Motorsport]

Resurrecting an old thread here - just checking in to see if anyones got a spec for the crankshaft float? The above says .2-.4mm but that seems really really high - was expecting something in the .05-.1 range?

 

[Radugns]

You mean lateral clearance? Is from 0.07 to 0.2.mm

 

[FrogJam Motorsport]

Yep - as in dti on the end of the crank and then lever the crank to/fro to see the clearance and then adjust with the thrust washers if needed.

I see why I’m baffled - there’s a zero missing the table above. Shows clearance as .7-.22 rather than .07-.22.

.22mm still sounds really high though!

what’s the rod/crankshaft lateral clearance row on about? Is that for rod side clearance?

 

[Radugns]

There was my mistake, 0.07 to 0.23 is the correct value. I will edit it.
The rod lateral clearance is correct from the table.

 

[Radugns]

UPDATED