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Scat crank 355

Started by _Barman_ , Aug 03 2009 08:15 PM

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31 replies to this topic

#1 _Barman_

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Posted 03 August 2009 - 08:15 PM

My rear main seal is leaking again,
I did it myself the first time, leaked straight away,
I got a mate to do it the second time,(hes a mechanic too with a lot more experiance than me )
It leaked after about half an hour,
Now ive got it out again,and im stuck for what to do,
Do i try someone else to do it,
Ive rang the Prostroke guys and their procedure involves a speacial tool and stuff i dont have.
Some things to think of:
The new crank has no cross hatch marks like the old 308 crank.
the second seal turned a little,
and ive realy got the shits with it,(theres only so many time you can take an engine in and out)
Baz
Is there a neoprene kit/seal that will fit a red block,If so whats the part number?

Edited by Barman, 03 August 2009 - 08:21 PM.

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#2 TerrA LX

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Posted 03 August 2009 - 09:20 PM

The new crank has no cross hatch marks like the old 308 crank.

That sounds like the problem.

The rope seal does not mate with this crank.

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#3 _Barman_

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Posted 03 August 2009 - 09:37 PM

I rang the prostroke guy he said none of the cranks have the cross hatch marks.

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#4 _rorym_

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Posted 03 August 2009 - 09:48 PM

Its farked...I will be up to get it on the weekend..a slab OK?
R

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#5 Struggler

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Posted 03 August 2009 - 09:52 PM

The deal with the Scat cranks is yes, they are SIZED for a rope seal but NO they don't have the knurling required for a successful rope seal installation.

Scat designed the cranks to be used with a Felpro 2903 rear main seal. This seal will need to be cut down to suit and sealant applied to the back of it to work as intended.

Hope this helps.

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#6 TerrA LX

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Posted 03 August 2009 - 09:52 PM

Even the harrop cranks have the knerling, it's to lube the rope.

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#7 _ass308_

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Posted 04 August 2009 - 07:34 AM

buy a harrop crank,its better than a scat anyways,comes with knurling.

flog the old crank off.

cheaper,and quicker than a new motor,

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#8 _rorym_

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Posted 04 August 2009 - 05:11 PM

I think the motor is built ASS..expensive solution...My Eagle has no crosshatching and doesnt leak.
R

Edited by rorym, 04 August 2009 - 05:18 PM.

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#9 _ass308_

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Posted 04 August 2009 - 06:08 PM

what sort of seal ?

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#10 _Bomber Watson_

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Posted 04 August 2009 - 06:43 PM

Any competent machine shop should be able to put he knurling in there for a reasonabley cheap price....

Cheers.

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#11 _Barman_

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Posted 04 August 2009 - 07:33 PM

Scat designed the cranks to be used with a Felpro 2903 rear main seal. This seal will need to be cut down to suit and sealant applied to the back of it to work as intended.

My local parts guy looked into the felpro part number, it doesnt egsist
he rang a place called precision and they said it will need the cross hatch,
so now hes chasing up a neoprene seal.
Im concidering Roryms idea and taking it to "straightline performance" in hervey bay.
baz

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#12 _Barman_

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Posted 04 August 2009 - 07:34 PM

Ive also emailed Prostroke for a written procedure on fitment.
Baz

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#13 _ass308_

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Posted 04 August 2009 - 07:51 PM

i have a neoprene seal,i think its out of a v6 buick.its on cross hatching

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#14 Struggler

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Posted 04 August 2009 - 08:04 PM

Barman, the Felpro 2903 does exist (as ASS308 says it is intended for a V6 Buick), I have some here. It is the ONLY neoprene seal you can use with a rope rear seal crank.

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#15 Toranavista

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Posted 04 August 2009 - 08:10 PM

It does exist
http://www.summitrac...r...02903&dds=1

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#16 _Barman_

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Posted 05 August 2009 - 04:11 AM

PM sent

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#17 _The Baron_

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Posted 05 August 2009 - 01:33 PM

Barman.

If it is not too late (pulled apart)

DO A LEAK DOWN TEST.

I had the same problem as you describe and Yes I replaced the seal just like you.

IT STILL LEAKED.

Then I had a leakdown test done that proved the problem was caused by blowby (around 10-30%)

Basically after 5,000 km, the rings were not bedded in because the cylinder honing job was crap and the rings not gapped/installed properly.

You can change the rear mains seal a million times and it will still fail to excessive BLOWBY.

You may not have the problem, but it would be a good way to eliminate blowby as a possible cause for you grief.

Good Luck!

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#18 _rorym_

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Posted 05 August 2009 - 04:27 PM

Good bloody point Baron!...Well done..
R

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#19 76lxhatch

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Posted 05 August 2009 - 04:53 PM

Still ain't gonna seal using rope without the knurling, whack the neoprene seal in and you will be happy

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#20 _rorym_

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Posted 05 August 2009 - 05:07 PM

Ring Ray!!!
R

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#21 _Barman_

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Posted 05 August 2009 - 07:02 PM

Baron
The first seal leaked straight away,burnt it
Second seal spun and leaked after a week.
and i have the crank out now,
but ill do a test before refitting it(engine),
Im also going to use an old kingwood chassis and put engine
in it and radiator and exhaust and run it for an hour before fitting it again.