Thank you Mike.
I had already discussed this (to me) fairly encouraging head with Russ.
My first reservation was that it looked as if part of it had been fettled using a coal chisel. Russ, of course was more professional. He pointed out that:
1. A piston had broken up in the left hand pictured cylinder, broken pieces of ring having been knocked into the head, and
2. The head had already been skimmed too much for my use. This is liable to cause over-thinned parts to overheat and pre-ignition (pinking). (This is the problem with my own heads)
Thanks again,
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Please don't post someone's email address to avoid it being harvested by spambots and it's against GDPR regulations.
Always look at "ACTIVE TOPICS" to see all posts in date & time order as they are sometimes moved; or look at "Your Posts".
Please add Reg. nrs. when posting a photo or anything about a car as this will help searches. Don't add punctuation next to nr. as this negates search.
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Pair of SP250 or saloon cylinder heads
Re: Pair of SP250 or saloon cylinder heads
Last edited by timmartin on Thu Jul 11, 2019 10:21 am, edited 1 time in total.
Tim
Blue 1964 SP250 in Berkshire
Blue 1964 SP250 in Berkshire
Re: Pair of SP250 or saloon cylinder heads
Colin and Graham. Just in case this changes your opinion about how much your heads have been skimmed already, this is how Russ checks whether there is enough metal left for him to rework a head. (Measuring the overall thickness of a head can sometimes produce either an over-pessimistic or an over optimistic-conclusion!)
1. Straight edge on the machined face, across the middle of each cylinder.
2. Measure depth to centre of combustion chamber, between the valves.
3. The minimum useable depth is one inch. (When new they are up to one inch and 40 thou. (1.040”)
My posting this does not imply that, unlike me, you need to be told how to suck eggs. Just double checking...
Thank you.
1. Straight edge on the machined face, across the middle of each cylinder.
2. Measure depth to centre of combustion chamber, between the valves.
3. The minimum useable depth is one inch. (When new they are up to one inch and 40 thou. (1.040”)
My posting this does not imply that, unlike me, you need to be told how to suck eggs. Just double checking...
Thank you.
Tim
Blue 1964 SP250 in Berkshire
Blue 1964 SP250 in Berkshire
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- Chief Geek
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Re: Pair of SP250 or saloon cylinder heads
Good information as I was to measure the depth of the head being 3.000 inches
Graham Emmett ¦ DLOC Chairman ¦ chair@dloc.co.uk ¦ 07967 109160
Northwich, Cheshire
DB18 1949 LCV522 (Yes that one with the P100s)
Northwich, Cheshire
DB18 1949 LCV522 (Yes that one with the P100s)
Re: Pair of SP250 or saloon cylinder heads
Hi
I have been in touch with the SP club and they said that the heads when new the thickness was 3 inches, which indicates that Grahams head have not been skimmed. As such they are hen's teeth.
Regards
Colin
I have been in touch with the SP club and they said that the heads when new the thickness was 3 inches, which indicates that Grahams head have not been skimmed. As such they are hen's teeth.
Regards
Colin
Re: Pair of SP250 or saloon cylinder heads
Thank you Colin.
I too understood that the nominal overall thickness of a new, machined head was three inches.
But I have heard of thicker ones being seen, up to as much as 3.060”.
It does seem unlikely that one or more of these thicker heads will turn up during my search, but it does suggest to me that measuring the combustion chamber depth may be the more certain way of assessing a used head?
Or have I got it wrong somewhere?
I too understood that the nominal overall thickness of a new, machined head was three inches.
But I have heard of thicker ones being seen, up to as much as 3.060”.
It does seem unlikely that one or more of these thicker heads will turn up during my search, but it does suggest to me that measuring the combustion chamber depth may be the more certain way of assessing a used head?
Or have I got it wrong somewhere?
Tim
Blue 1964 SP250 in Berkshire
Blue 1964 SP250 in Berkshire
Re: Pair of SP250 or saloon cylinder heads
On the question of head thickness :- 3.0" when new... with std pressed steel gaskets skimming up to .035" can be utilized..
The alternative 'composite' gaskets as supplied today are approx .040" thick.. in practice these allow for a safe skim of +/-.060"
The alternative 'composite' gaskets as supplied today are approx .040" thick.. in practice these allow for a safe skim of +/-.060"
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- Chief Geek
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- Joined: Mon Feb 08, 2016 8:12 pm
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Re: Pair of SP250 or saloon cylinder heads
Tim, are you still after the two heads? I’ve located two which have the required depth, pretty sure never been skimmed and have little visible corrosion around the waterways.
Graham Emmett ¦ DLOC Chairman ¦ chair@dloc.co.uk ¦ 07967 109160
Northwich, Cheshire
DB18 1949 LCV522 (Yes that one with the P100s)
Northwich, Cheshire
DB18 1949 LCV522 (Yes that one with the P100s)
Re: Pair of SP250 or saloon cylinder heads
Thank you Graham. I have replied to you by email and am consulting Russ and Andrew.
Tim
Blue 1964 SP250 in Berkshire
Blue 1964 SP250 in Berkshire
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- Classic Wise Man
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Re: Pair of SP250 or saloon cylinder heads
Hello Tim,
I have sent you a PM that may be of interest to you.
All the best.
Richard.
I have sent you a PM that may be of interest to you.
All the best.
Richard.
1968 Daimler V8-250 Saloon
DLOC East Sussex Branch Secretary
DLOC 2.5L V8 & V8-250 Registrar - https://www.dloc.org.uk/v8-250
DLOC 2024 International Rally - https://www.dloc.org.uk/rally-2024
DLOC East Sussex Branch Secretary
DLOC 2.5L V8 & V8-250 Registrar - https://www.dloc.org.uk/v8-250
DLOC 2024 International Rally - https://www.dloc.org.uk/rally-2024