5efe Crank problem

tip

Member +
Hi, i've bought a 5e engine from a friend, but the crank is damaged...

I'd like to know if it's a good idea to machine the crank for oversized crank and rod bearings...
 

Skalabala

Member +
There is no problem what so ever! Make sure that the place to machine it is reputable!
You can even run big boost if it was cut.
Look for 0.25mm/10 thou bearings :) ACL Duraglide is a good choice.
 

tip

Member +
Hi, are these bearings used for Race applications?

do you have a similair link for race engine bearings? like acl race or King bearings...
 

Skalabala

Member +
You will need to email raceengineering and ask them.
But there is nothing wrong with Duraglide.
You will break other stuff before the bearing goes.
If the bearings gets the correct amount of oil and the correct oil you will NOT have problems!
A bearing is a bearing, makes use of hydro planing. Any good brand will do the job!
You can run 500HP with no problems, remember 5E journals are way superior to 4E as it is bigger.
And Race ACL is actually not the best thing to use, the bearing does not wear easily under insane loads and thus it eats the crank!
 

spuddy

Ulster Area Rep.
ACL don't do their RACE version for 4E or 5E, I use Duraglide with near 600hp and dont have a problem, though I'm paranoid and open the engine up now and then for inspection.
 

Texx

Super Moderator
4E mains are 46.985mm - 47.000mm, big ends are 39.985mm - 40.000mm

5E mains are 49.985mm - 50.000mm, big ends are 42.985mm - 43.000mm
 

tip

Member +
Hi does anyone know the Crank clearances for the 5e?
i brought a 5EFE crank to a machine shop and they told me that the clearance now is 0.003''. and he asked me if i wanted to regrind it 1st oversize or if i want to leave it how it is..., what should i do? (i don't know much about engine building jet.)

i've read somewhere that the clearance should be 0.002'', but i'm not sure.
 

tip

Member +
thanks very much guys. so even if i'm going to boost my 5e i should stay with a clearance of 0.002''?
 
Last edited:

AdamB

Member +
Skalabala, would you prefer to see closer to 0.006" then as standard clearence? Why would it be better to run a tighter oil clearence? Will it prevent the bearings from starving of oil?
Do agree the 0.002" is a fairly large clearence and bearings would be better off being replaced earlier or atleast checked.
 

Skalabala

Member +
The smaller the clearance the stronger the hydroplaning effect gets and thus the chance of having metal to metal contact gets less.
0.006" = bearing knock!
And boost can squash the oil in the bearing and then you get metal to metal contact. Same with high revving.
A good clearance that is strong for hydroplaning and ample oil to lubricate and cool is 35 microns on a 40mm journal.
 

AdamB

Member +
Thats strange mate because the 5E manual I have here says:
Main bearings oil clearence standard size........... 0.0006"-0.0014"
Rod Bearing Oil clearence standard size..............0.0006"-0.0019"

Or am I reading the wrong bit? lol.
 

Skalabala

Member +
Don't think so, looks like you just made a type error (0.006")
The specs you have there are good clearances. But the mains can go bigger without problems :)
 
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