Valve Clearances Perkins 6-354

[Capstan]

OK this is sooo confusing.
When we follow the book:
Get No 1 on the rock and set No. 6 clearances. Well that is OK for the #6 inlet but #6 exhaust is halfway down (or up) so you would have to back it off so far that you are going to drop the rod when it is fully open.



Also the book says .08 for Inlet and .18 for Exhaust
However on the manual one of the previous owners has written.12 for inlet and exhaust. Spoken to a mechanic and he says the old were .12 but now it is .08 and .18
So do we go with .12 or the new .08 and .18?




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These were probably built 69- 70

 

[ctjstr]

I'm not that familiar with that particular engine, but my guess would be that you don't have the engine on the compression stroke. Roll it over 360 and check again.

as for the difference between the valve specs. I'd ask another mechanic. .18 seems like a big jump from .12. I'm not sure why they would make such a change. Maybe to build more cylinder pressure? Its a big enough change that I'd ask around some more to get comfortable with the explanation.

good luck

toni

 

[Capstan]

I'm not that familiar with that particular engine, but my guess would be that you don't have the engine on the compression stroke. Roll it over 360 and check again.

as for the difference between the valve specs. I'd ask another mechanic. .18 seems like a big jump from .12. I'm not sure why they would make such a change. Maybe to build more cylinder pressure? Its a big enough change that I'd ask around some more to get comfortable with the explanation.

good luck

toni

Thanks Toni,
We had it on compression stroke. It seems that the .08 and .18 was throwing us. That and along with the way they tell you to do it in the manual.
Spoke to a service engineer Trans Atlantic Diesel who was extremely helpful. And basically said forget the manual and set inlet and exhaust at .12 when on the rock.
He said "You can't go wrong doing it that way"
All good. (So far)

 

[FOG]

I just looked in my Perkins Workshop Manual dated 1982 and it says; 0.012 in. (0.30 mm) cold for both intake and exhaust.

 

[Ski in NC]

Position crank so #6 both are rocking, and at that crank position set #1. At that position, #6 is at tdc between int and exh strokes, #1 is at tdc firing position. Repeat with 2 and 5, then 3 and 4. Those pairs of pistons move exactly the same.

You will end up moving crank 120deg between each setting.

Don't set #6 when it is rocking, you will end up with too much clearance.

 

[ksceviour]

I've got a Perkins Range 4 model 135, 6.3544. Both the original users manual and my workshop manual (amendments valid to June 1992) state the tip clearances should be .008 in for the inlet and .012 in for the exhaust. The marine supplement of the workshop manual indicates that there was a camshaft part number change after engine number TW ---U626522G but the valve tip clearances remain the same.

Setting both to .012 inches is ball parking it when you don't have to. The manufacturer has printed the specs. That's a potential .004 error on the inlet and .006 on the exhaust. I'll be checking mine this season (just waiting on a new cover gasket).