Author Topic: Head gasket  (Read 994 times)

Offline morris

  • Wise & Enlightened
  • *
  • Join Date: Aug 2012
  • Posts: 1686
  • Karma: 26
  • Antwerp, Belgium
Head gasket
« on: 26.05. 2014 22:00 »
Hi lads,
wonder if anyone has some experience with carbon fibre head gaskets?
I ordered one for the plunger (low compression)

2nd question; I received a set of valves I ordered, and as there was no parts number on the wrap, and neither on the valves, I was wondering which is the exhaust and which one the inlet. I figured the one on the left must be the exhaust as the stem is heavier at the base than the one on the right.
Thanks
'58 BSA A 10 SA
'52 BSA A 10 Plunger
'55 MORRIS ISIS
The world looks better from a motorbike
Belgium

beezermacc

  • Guest
Re: Head gasket
« Reply #1 on: 26.05. 2014 22:10 »
I'm pretty sure that exhaust valves are not attracted by a magnet.

Offline trevinoz

  • Newcastle, N.S.W. Australia.
  • Wise & Enlightened
  • *
  • Join Date: Jul 2006
  • Posts: 3004
  • Karma: 71
Re: Head gasket
« Reply #2 on: 26.05. 2014 22:10 »
Interesting head gasket, Morris.
I have never heard of them and will be very interested in your future experience with it.
As to valves, in the old days the sure way to determine an exhaust valve was to use a magnet, the exhaust being non magnetic.
Nowadays, valves are being made from stainless steel so I am not sure how to test, if there is any difference.

Trev.

Offline morris

  • Wise & Enlightened
  • *
  • Join Date: Aug 2012
  • Posts: 1686
  • Karma: 26
  • Antwerp, Belgium
Re: Head gasket
« Reply #3 on: 26.05. 2014 22:48 »
Just checked. All four are stainless.
'58 BSA A 10 SA
'52 BSA A 10 Plunger
'55 MORRIS ISIS
The world looks better from a motorbike
Belgium

Offline trevinoz

  • Newcastle, N.S.W. Australia.
  • Wise & Enlightened
  • *
  • Join Date: Jul 2006
  • Posts: 3004
  • Karma: 71
Re: Head gasket
« Reply #4 on: 27.05. 2014 00:43 »
Then I suppose it doesn't matter where you fit any valve.

Trev.

Online BSA_54A10

  • Wise & Enlightened
  • *
  • Join Date: May 2008
  • Posts: 2134
  • Karma: 33
    • BSA National
Re: Head gasket
« Reply #5 on: 27.05. 2014 08:32 »
Well as the exhause runs in the red-yellow heat range & the inlet barely colours except at the face I would look at putting the heavier on in the exhaust..

OTOH I have a theory on unbranded parts.
Put them on evilbay and let them destroy some one else's engine.

Quality parts will always be either branded or arrive in a very clearly branded packaging
If the supplier can not afford ( or is too cheap to pay )  the extra 25¢ for printed packaging, then what sorts of short cuts have they taken with the parts ?
Bike Beesa
Trevor

Online bsa-bill

  • Wise & Enlightened
  • *
  • Join Date: Mar 2006
  • Posts: 5697
  • Karma: 66
Re: Head gasket
« Reply #6 on: 27.05. 2014 10:47 »
Ah - are the ex and in  valves both the same size on plungers then, s/a inlets general bigger than ex (talking valve size not stem)

if the stems are different then the guides should be too, measure or wiggle test
All the best - Bill
1961 Flash - stock, reliable, steady, fantastic for shopping
1959 Rocket Gold Flash - blinged and tarted up  would have seizure if taken to  Tesco

Online muskrat

  • Global Moderator
  • Wise & Enlightened
  • **
  • Join Date: Jul 2009
  • Posts: 8850
  • Karma: 113
  • Lithgow NSW Oz
    • Shoalhaven Classic Motorcycle Club Inc
Re: Head gasket
« Reply #7 on: 27.05. 2014 11:34 »
I sort of agree with BSA-54A10.
But if you have to, the heavier stem to head section is ex. I think there's only 30thou" difference in head size.
'51 A7 plunger, '57 A7SS now A10CR,  '83 CB1100F, 88 FXST .
Australia
Muskys Plunger A7

Offline morris

  • Wise & Enlightened
  • *
  • Join Date: Aug 2012
  • Posts: 1686
  • Karma: 26
  • Antwerp, Belgium
Re: Head gasket
« Reply #8 on: 27.05. 2014 20:22 »
Well as the exhause runs in the red-yellow heat range & the inlet barely colours except at the face I would look at putting the heavier on in the exhaust..

Exactly what I was thinking also Trevor
Valve stems are measuring .310" all four so in theory they can be used all around
The only difference is the stem base where two of them are heavier where they widen towards the valve, which supports your theory

Quality parts will always be either branded or arrive in a very clearly branded packaging
If the supplier can not afford ( or is too cheap to pay )  the extra 25¢ for printed packaging, then what sorts of short cuts have they taken with the parts ?
Must add that they came from Draganfly UK as did the head gasket.
I don't think it's in there interest to sell lousy quality parts? (I hope *dunno*)


'58 BSA A 10 SA
'52 BSA A 10 Plunger
'55 MORRIS ISIS
The world looks better from a motorbike
Belgium

Offline ericjervis

  • Moving Up
  • **
  • Join Date: May 2014
  • Posts: 5
  • Karma: 0
Re: Head gasket
« Reply #9 on: 02.06. 2014 18:25 »
As to the gasket, I just fitted one today. After fitting one last week and destroying it. You need to use Wellseal with these, and last week I put the Wellseal on the barrel, stuck the gasket on top, put Wellseal on the top face of the gasket, lowered the head carefully into position and bolted it up. Some of the bolts didn't go in easily so I thought the gasket was probably a gnat's whisker too small round that particular hole, poked a small screwdriver down there and inserted the bolts, torqued 'em down and tried putting the pushrods in. Oh dear. Shone a torch down there and saw that the gasket had slipped an inch towards the back! Today, a wiser Eric stuck the gasket to the head, Wellsealed the bottom face, then placed four domino-sized bits of wood on the extremities of the fin area of the barrel, placed the head carefully onto them, and examined the result, shining a torch down each bolt hole and adjusting the position slightly, inserted the bolts VERY carefully, tightend them finger tight, inserted two longer bits of wood at the sides, removed the original bits, then the two new bits, and allowed the head to settle down nicely onto the barrel. (With a clunk). So far it's looking good.