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Mon Sep 12, 2011 1:36 am

I have searched high and low and can not get a straight out answer. I have a 88mm crank and the conn rod journals measure 1.80 The rod bearings are standard so the journals have not been machined. What are these rods? Porsche, Buick or what. They measue 5.5 center to center on the small to big end. I assume thats how to measure them? I have not measured the width of the big end. Any info please? Oh, i guess I should mention that this is a type 1 crank.
Bret

Mon Sep 12, 2011 2:36 am

If it's an undersize it could be rabbit or nascar for all we know

If you can get exact measurements of the rod big end, bearing width(you'll have to look at the rods and crank and make a good guess) and crank size, I can look in the catalog and see if anything matches

Do you have any old bearings with a PN on them? (that would be too easy)

Mon Sep 12, 2011 7:38 am

That's an odd size. Even small Honda journals are 1.85". Interesting to see where this goes.

Who built the crank?

RC

Mon Sep 12, 2011 10:57 am

The VW Rabbit rod measures at 1.810" for STD
The problem they had with them the journal was so small there not enough or any overlap with main journals.
This causes the crankshaft to flex which causes all kinds of other problems.
The use of that size of rod journal fell out of favor years ago because of the problems encountered.
If you are planning on using the crankshaft, high RPMs would not be recommened.
The use of wristpin button recommened as snaprings tend to pop out from the flexing.

Mon Sep 12, 2011 11:02 am

Need more info: Rod big end size, bearing width, and bearing thickness would help. Are there any other markings on the bearing?

Mon Sep 12, 2011 12:18 pm

For reference: Buick = 1.989 on the crank I just measured.

Mon Sep 12, 2011 1:12 pm

yamaducci wrote: For reference: Buick = 1.989 on the crank I just measured.

That would be a Buick/Chevy journal ground 0.010" under.

Mon Sep 12, 2011 4:48 pm

I will measure everything when I get off work. I do also have the bearings for reference. Not sure who made the crank but it is a 88mm and the rod is a 5.5 length.

Mon Sep 12, 2011 7:54 pm

1.800" could be std. Corvair ?

Mon Sep 12, 2011 8:32 pm

Ok here we go:
Big end no bearing 1.935
" " with bearing 1.815
Big end width .890
Bearing width .743
Bearing part number 85 859 600
31593 There is two numbers on it, one on each end of bearing. The bearing is std.
Small end w/o bushing .948
" " w/bushing .868
This is a 5.5 inch rod
One number on crank 4415 stamped on end of counterweight.
Any other help is appreciated.[img][/img]

Mon Sep 12, 2011 8:37 pm

RockCrusher wrote: That's an odd size. Even small Honda journals are 1.85". Interesting to see where this goes.

Who built the crank?

RC
Thats a good question. I bought it used and it has no markings on it other than 4415 stamped on the end of a flyweight. The case is a ARPM and it has Rimco 20866 stamped on the main seal flange, which is who I assume did the machine work at one time and it might be a r/o number?

Mon Sep 12, 2011 9:36 pm

1432 is right, my bad

Tue Sep 13, 2011 3:03 pm

modok wrote: It's close to rabbit
here's the spec, they have many different PN with the same sizes

1.8802/ 1.8810 (crank)
47.757/ 47.777

1.9921/ 1.9929 (housing)
50.599/ 50.620

0.7480 (width)
19.00

That is probably a KS bearing number, but unfortunately I have no info from them

Did you torque the rod and measure it proper?

Im not much of a water pumper kinda guy, any clue where I might find some bearings and one conn rod?

Tue Sep 13, 2011 3:09 pm

jsturtlebuggy wrote: The VW Rabbit rod measures at 1.810" for STD
The problem they had with them the journal was so small there not enough or any overlap with main journals.
This causes the crankshaft to flex which causes all kinds of other problems.
The use of that size of rod journal fell out of favor years ago because of the problems encountered.
If you are planning on using the crankshaft, high RPMs would not be recommened.
The use of wristpin button recommened as snaprings tend to pop out from the flexing.
Is this poszibly the cause of the weird wave effect on the sides of the cylinder bores? It almost appears to look and feel like a series of whoops at the dunes or on a motocross track.

Tue Sep 13, 2011 4:47 pm

These bearings are available from clevite, and also most other bearing manufacturers, they aren't rare

What's wrong with the rod?
Does the crank need re-ground?

Tue Sep 13, 2011 6:21 pm

modok wrote: It's close to rabbit
here's the spec, they have many different PN with the same sizes

1.8802/ 1.8810 (crank)
47.757/ 47.777

1.9921/ 1.9929 (housing)
50.599/ 50.620

the 1.6 lt Rabbit is closer to the numbers.

1.811" 46mm journal
1.929 " 49mm housing bore

Tue Sep 13, 2011 6:48 pm

your right, I copied and pasted the wrong one

Tue Sep 13, 2011 8:30 pm

modok wrote: These bearings are available from clevite, and also most other bearing manufacturers, they aren't rare

What's wrong with the rod?
Does the crank need re-ground?

The no 1. spun. It got hot enough to blue the big end. The crank journal suprisingly looks pretty good and plasti gauges good at .015 I will have it atleast polished and inspected. I just do not trust the rod when they blue like that. I have had others fail after resizing. They just do not sem to hold thier shape any longer.
So to sum up, it looks like I need to find a 5.5 Rabbit H Beam rodfrom a 1.6 engine, turn the crank and keep the rpm at 6500 or lower. Sound about right?

Tue Sep 13, 2011 9:07 pm

bummer
I would fix the rod If it was me, there are tricks,
but your right it IS a risk

If there was a lot of heat I betcha the crank is bent,
check the runout

all I was thinking, is if you need it reground, you should get the bearings and rods done first, then have it ground for proper clearance.

here's spec for "EH" or "EJ" vw, like a 1980 model
ACL pn: 4B1636 OR clevite PN: CB1017P
crank
45.949/1.8090
45.969/1.8098
housing
49.000/1.9291
49.017/1.9298
max thickness
1.506/0.0593
clearance
.018/.0007
.082/.0032
width
19.00/0.748

the corvair bearing is narrower
Clevite Rod Bearing CB-584P
crank1.7990/1.8000
thickness 0.0620
housing 1.9247/1.9252
width 0.6840

Tue Sep 13, 2011 11:48 pm

WHEN U SAY TRICKS CAN BE DONE TO SAVE THE ROD, WHAT ARE YOU SPEAKING OF? Oops, caps lock on... I think the crank is ok although it will be checked. I am thinking of going to a 84mm with some 2 inch journals and get away from the 88mm and the tiny journals.