Author Topic: cyl head bolts  (Read 1538 times)

Online chaterlea25

  • Wise & Enlightened
  • *
  • Join Date: Jun 2009
  • Posts: 4130
  • Karma: 54
Re: cyl head bolts
« Reply #15 on: 31.03. 2022 23:25 »
Hi All,
I have found that the bolt seating areas even on iron heads gets dished and pinches inwards around the bolt shank.
I spotface the areas and run a drill through the holes, then make 1/8th in. thick washers from bar stock
I put a dab of anti seize under the bolt heads and on the threads then torque them down

I have not needed to re torque the head on my SR,  I checked a couple of the outer ones soon after I built the engine and they were OK
That was almost 20 years ago :o

Any of the other engines I have put together have not come back to me with head gasket problems!! Touch Wood *eek*

John
 
1961 Super Rocket
1963 RGS (ongoing)

Offline Greybeard

  • Jack of all trades; master of none.
  • Wise & Enlightened
  • *
  • Join Date: Feb 2011
  • Posts: 9982
  • Karma: 50
Re: cyl head bolts
« Reply #16 on: 01.04. 2022 13:50 »
I also do not recheck the head bolts. I use a solid copper gasket, annealed every time. I had a friend make me a set of thicker washers for the bolts, (something I could do myself now I have a lathe 👍). I have a clicky torque wrench. I take the bolts down to 35ft/lbs. I then go round them again, backing them off a bit and retightening. I try to do that without stalling the action.

PS: It's very likely that some of you guys ride harder than I do so you put the head gasket under more stress than me 😜.
Greybeard (Neil)
2023 Gold Star
Supporter of THE DISTINGUISHED GENTLEMAN'S RIDE https://www.gentlemansride.com

Warwickshire UK


A Distinguished Gentleman Riding his 1955 Plunger Golden Flash

Offline RDfella

  • Wise & Enlightened
  • *
  • Join Date: Aug 2017
  • Posts: 2210
  • Karma: 15
Re: cyl head bolts
« Reply #17 on: 06.04. 2022 10:18 »
Seems I was wrong - BSA fitted yield bolts from new. At least, one of mine was ......
'49 B31, '49 M21, '53 DOT, '58 Flash, '62 Flash special, '00 Firestorm, Weslake sprint bike.

Online groily

  • Wise & Enlightened
  • *
  • Join Date: Jul 2007
  • Posts: 1956
  • Karma: 33
    • www.brightsparkmagnetos.com
Re: cyl head bolts
« Reply #18 on: 06.04. 2022 10:42 »
Ha!
Would that be 'Waisted', or 'wasted'??
Bill

Offline Peter in Aus

  • Valued Contributor
  • ****
  • Join Date: Feb 2014
  • Posts: 431
  • Karma: 2
  • South West, West Australia
Re: cyl head bolts
« Reply #19 on: 07.04. 2022 01:36 »
I make my own head bolts out of HT Alon head cap screws, use thick washers and soled carbon fibre head gasket, leave over night and retighten, never need checking after that. I should add that is for iron head.
Peter

Busselton West Australia
49 A7 longstroke
58 A10  SA

Offline RDfella

  • Wise & Enlightened
  • *
  • Join Date: Aug 2017
  • Posts: 2210
  • Karma: 15
Re: cyl head bolts
« Reply #20 on: 07.04. 2022 20:04 »
Kicking myself now. Had thought of buying some M10 Allen bolts long enough that the unthreaded portion would allow me to reduce to 3/8" dia and thread BSF. Then,  remembering BSF capscrews are available, I looked into that option concurrently with looking into what known sellers had available in BSA head bolts. Being in a hurry to get the job finished, I placed an order for the latter.
In my haste, I'd overlooked that the capscrews (high tensile and always reliable - never had a failure in the 58yrs I've been using them) are actually less than half the price of the head bolts I'd ordered.  *bash*
And so I've ordered the capscrews too, and the 'genuine reproduction' head bolts will be going into storage as I've no doubt the former are of better quality.
'49 B31, '49 M21, '53 DOT, '58 Flash, '62 Flash special, '00 Firestorm, Weslake sprint bike.

Offline Richard Hinton

  • Moving Up
  • **
  • Join Date: Jun 2022
  • Posts: 44
  • Karma: 0
Re: cyl head bolts
« Reply #21 on: 21.06. 2022 09:04 »
A10 Gold flash
Aneal the head gasket first then i torqued my head down to 30ft lbs, left it for a few days then rechecked to see if had settled and final torqued to 32ft lbs. till now clocked up 2500 miles and all seems good. but i'm sure something else will will happen its British
1960 GF