Engine rebuild tolerances

[Tomo3292]

Looking at doing an engine refresh, ready for reliability on track.

Where can I find the tolerances for bores, bearings, crankshaft and piston rings.

Any advice welcome

 

[JamesBryan]

Ask @bloke or @NorthloopCup nicely and they might tell you.

 

[Tomo3292]

@bloke @NorthloopCup,

Morning gents I've heard anytime your the 2 go guys on here, with outrageous knowledge on the little clios.

I am contemplating doing a full engine rebuild, but after the tolerances mentioned above. Where am I likely to find these and can you shed any light on its worth doing the following.

Piston rings placement
Main bearings
Big end bearngs
Thrust washers
New pulleys and belts
New gaskets
New stem seals
Relap valves

Maybe looking at potentially some head work too, thinking of a skim, porting and polishing, and maybe some cat cams.

I'm pretty handy with the spanners, I have bore measuring device and also micrometer so I can do the measuring, just want to make sure it's done correctly.

Your help and advice would be greatly appreciated

 

[bloke]

Think everything is in the factory manual? Can download it easy enough. If not though you're just working to 'normal clearances etc.
With ring gaps majority of the time I've found they are pretty much ok out of the box but obviously that can vary from make to make and also bore wear.

 

[Tomo3292]

@bloke cheers pal.

 

[NorthloopCup]

@Tomo3292 here’s the R3 197 engine specs.

 

[Tomo3292]

@NorthloopCup thank you very much. Knew I seen it before, but couldn't find it at all when I needed it.

Only thing that worries is I've heard these engine can have dramas with spinning the 3rd bearing and I'm also hoping when I measure the crank end float the thrust washers I can use are standard size.

 

[NorthloopCup]

@NorthloopCup thank you very much. Knew I seen it before, but couldn't find it at all when I needed it.

Only thing that worries is I've heard these engine can have dramas with spinning the 3rd bearing and I'm also hoping when I measure the crank end float the thrust washers I can use are standard size.

Post a pic up of your crank mate and I’ll be able to tell you how likely it is to happen.

 

[bloke]

Post a pic up of your crank mate and I’ll be able to tell you how likely it is to happen.

nothing to do with the oilway drilling by any chance?

 

[NorthloopCup]

nothing to do with the oilway drilling by any chance?

The design more than anything mate.

 

[Tomo3292]

Post a pic up of your crank mate and I’ll be able to tell you how likely it is to happen.

Will do mate when I get the time looli g at starting the rebuild within the next month as currently in romania with work.

 

[bozothenutter]

how hard would it be to have the block and tods tanged?

 

[NorthloopCup]

how hard would it be to have the block and tods tanged?

No problem for a decent machinist.

 

[Tomo3292]

Post a pic up of your crank mate and I’ll be able to tell you how likely it is to happen.

@NorthloopCup crwnk measured with a micrometer and all within tolerances. No deep scoring or pitting anyway, just a few dull shiny marks on the surface. I'm going to get it nicely polished up. Any pros to running King Bearings for a standard build? Probably get some cams and port matched inlets but that about it. Or is it best to stick a set on oe renault bearings in.

 

[NorthloopCup]

@NorthloopCup crwnk measured with a micrometer and all within tolerances. No deep scoring or pitting anyway, just a few dull shiny marks on the surface. I'm going to get it nicely polished up. Any pros to running King Bearings for a standard build? Probably get some cams and port matched inlets but that about it. Or is it best to stick a set on oe renault bearings in.

King bearings have larger tolerances iirc as they’re more race biased, so you’re better off with standard bearings. Also, that crank is one of the ones that will potentially spin a centre main. All luck of the draw though I’m afraid.

 

[Tomo3292]

King bearings have larger tolerances iirc as they’re more race biased, so you’re better off with standard bearings. Also, that crank is one of the ones that will potentially spin a centre main. All luck of the draw though I’m afraid.

@NorthloopCup how do you work that one out mate? Is it due to the oil holes in the crank? Surely the best way would be to get tanged and better bearings? Or just try my luck with OE Bearings.

 

[NorthloopCup]

@NorthloopCup how do you work that one out mate? Is it due to the oil holes in the crank? Surely the best way would be to get tanged and better bearings? Or just try my luck with OE Bearings.

It’s due to the lack of counterbalance weights on the crank mate.
If it’s going to spin, the tags on the block/rods won’t stop it. The crank flexes due to the poor design.

Trust me mate, I’ve been around these engines now for quite some time, so I know their downfalls.

 

[NorthloopCup]

@Chambers_RS

 

[bozothenutter]

It’s due to the lack of counterbalance weights on the crank mate.
If it’s going to spin, the tags on the block/rods won’t stop it. The crank flexes due to the poor design.

Trust me mate, I’ve been around these engines now for quite some time, so I know their downfalls.

So the 'good' crank is the 197 one right?

 

[NorthloopCup]

So the 'good' crank is the 197 one right?

So the ph1 crank is the best crank. Then the 197, and followed by the 182 crank. The ph2 172 crank is still rubbish.

 

[bozothenutter]

So the ph1 crank is the best crank. Then the 197, and followed by the 182 crank. The ph2 172 crank is still rubbish.

Thanks!, I'll get it right someday....🙄
Any such difference in blocks?

 

[NorthloopCup]

Thanks!, I'll get it right someday....🙄
Any such difference in blocks?

The best blocks are the ones that have seen some heat cycles. Then they need checking for straightness of bores and journals, and machining if they’re out.