C2270 3.8 Locating Cylinder Head Stud problems ?

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splosh
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#1 C2270 3.8 Locating Cylinder Head Stud problems ?

Post by splosh » Fri Jul 12, 2019 11:22 pm

Hi,
I purchased the 3.8 (C2270) Cylinder Head Locating Stud last year from SNG along with the remaining new studs for my engine overhaul.
I have now started putting the head back together and noticed firstly that the widest part of this locating stud (the shoulder) will in no way enter the head in the correct location as it is too large diameter .
Secondly, the thread on the stud for locating into the block is a slightly smaller diameter which leaves this stud wobbling in the block. Tried the stud in all other block holes and exactly the same and wobbles like no tomorrow. Tried a conventional straight new stud (C29035#) in its location and they are tight on the thread.
The consequence is that this stud when fitted (after fettling it to the correct diameter for going into the head on its flange) is going to possibly pull out when torqued up. I know this from experience as it has happened before on another stud.
So, as I have read numerous reports on these studs that they don't fit into the heads as they are supplied with a too large shoulder - has any one else had a similar problem with the diameter of the thread on the stud when trial fitting to the block ?? Or, does anyone know if this specific stud is specifically required for its head locating purposes - or, any alternative sources for a better quality C2270 Head Stud ?? :helpsign:
Clive
August 1961 Flat floor ots

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abowie
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#2 Re: C2270 3.8 Locating Cylinder Head Stud problems ?

Post by abowie » Fri Jul 12, 2019 11:52 pm

I'm sure you know this and have fitted it correctly, but just checking :bigrin: This is the dowel stud that positively locates the head. So it goes in with the fat bit down on the block surface.

That said I agree something's wrong there. It is by no means unheard of for all of the usuals to sell substandard parts from time to time. I'd ring SNGB and ask them first. They might be able to help. The problem then is that all the retailers probably get their stock from the same manufacturer in China so you may run into problems there too.

XKS in the US sell ARP studs, and I have used them on engines before. They are of really high quality but I'm not sure that mixing and matching is necessarily a good idea.

Given that you're using C2270 I'm assuming you're taking about an early 3.8 engine? One option if you're not super concerned with originality is to fit the later long studs with the 2 aluminium engine lifting brackets.

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Andrew.
881824, 1E21538. 889457..oops
http://www.projectetype.com/index.php/the-blog.html
Adelaide, Australia

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#3 Re: C2270 3.8 Locating Cylinder Head Stud problems ?

Post by splosh » Sat Jul 13, 2019 10:40 am

Excellent reply and thank's.
Yes, the stud is up the correct way with the fat bit down.
The engine is a very early 1961 in a flat floor and originality is priority so I won't be able to use the studs for the lifting eyes - but a great idea.
I'll speak to SNGB on Monday, plus i'll give a few engineers a call to see if they have alternative suppliers.

I pointed this error out on the forum in case anyone else has the same scenario as its catastrophic if anyone gets to the final torque settings and it pops out.
By the way, the shouldered stud does pass through the head clearly all the way... :drinkingcheers:
Clive
August 1961 Flat floor ots

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#4 Re: C2270 3.8 Locating Cylinder Head Stud problems ?

Post by splosh » Sat Jul 13, 2019 10:43 am

Incidentaly, does the ARP Studs have the shouldered stud also in their kit ???
Clive
August 1961 Flat floor ots

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MarkRado
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#5 Re: C2270 3.8 Locating Cylinder Head Stud problems ?

Post by MarkRado » Sat Jul 13, 2019 10:48 am

Same experience, I reduced the diameter of the stud shoulder by turning on a lathe - but it always takes us back to specification of reproduction parts...
Mark
1963 OTS 880436

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#6 Re: C2270 3.8 Locating Cylinder Head Stud problems ?

Post by 288gto » Sat Jul 13, 2019 11:06 am

Same experience regarding the poor quality threads from SNG Barratts so bought a set from Rob Beere. You would need to ask him if he will sell you just one but to be honest if the threads are not particularly good on the Barratts ones I'd probably send them back and buy a full set from Rob Beere. They are very helpful and knowledgeable as the result of building engines themselves.

http://www.rob-beere-racing.co.uk/engin ... ead%20stud

Simon
Simon
1969 S2 OTS

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#7 Re: C2270 3.8 Locating Cylinder Head Stud problems ?

Post by abowie » Sat Jul 13, 2019 9:57 pm

splosh wrote:
Sat Jul 13, 2019 10:43 am
Incidentaly, does the ARP Studs have the shouldered stud also in their kit ???
XKS sell them and at a reasonably comparable price.
Andrew.
881824, 1E21538. 889457..oops
http://www.projectetype.com/index.php/the-blog.html
Adelaide, Australia

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#8 Re: C2270 3.8 Locating Cylinder Head Stud problems ?

Post by mgcjag » Sun Jul 14, 2019 7:10 am

Just for info i have flaged this with SNG as they have been mentioned above a few times.......Steve
Steve
1969 S2 2+2 & Building a C type replica

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#9 Re: C2270 3.8 Locating Cylinder Head Stud problems ?

Post by splosh » Sun Jul 14, 2019 10:55 am

I am glad this is now flagged with SNGB as for an untrained eye this could be catastrophic for someones cylinder head. Yes, I have noticed this topic has been discussed many times.
Incidentaly, I ordered some tappet shims and they arrived correctly etch marked with the part identifiying number - BUT they were two sizes bigger !!! Quality control needs tightening. So, please check your tappet shim sizes before fitting them and don't rely they are supplied correct.
Just thought it was worth mentioning..
Clive
August 1961 Flat floor ots

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#10 Re: C2270 3.8 Locating Cylinder Head Stud problems ?

Post by mgcjag » Sun Jul 14, 2019 12:28 pm

Hi.Splosh.......whats your name...can you please try to put it with your car model in the signature area....re shims...have you raised this issue with the supplier...Steve
Steve
1969 S2 2+2 & Building a C type replica

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#11 Re: C2270 3.8 Locating Cylinder Head Stud problems ?

Post by splosh » Sun Jul 14, 2019 5:16 pm

Hi Steve, Signature added. I will be on the phone to the supplier 1st thing in the morning as this problem with the head stud was only found late friday afternoon.
Clive
August 1961 Flat floor ots

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#12 Re: C2270 3.8 Locating Cylinder Head Stud problems ?

Post by splosh » Sun Jul 14, 2019 5:21 pm

P.S. The tappet shims problem was duly reported on the 26th June and still awaiting new stock. However, I waited long enough and obtained the correct ones from Rob Beere's stock last Wednesday which arrived the next morning.
Clive
August 1961 Flat floor ots

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265bhp
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#13 Re: C2270 3.8 Locating Cylinder Head Stud problems ?

Post by 265bhp » Sun Jul 14, 2019 8:02 pm

I highlighted exactly this issue with SNG around 18 months ago....!, that is not impressive
1963 3.8 FHC in slow restoration mode
1974 2.7 Carrera now as an RS Touring

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#14 Re: C2270 3.8 Locating Cylinder Head Stud problems ?

Post by splosh » Sun Jul 14, 2019 9:17 pm

3rd January 2018 I ordered my Head Studs. I know its a little later know but I have been restoring an Aston Martin in that time.
Clive
August 1961 Flat floor ots

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#15 Re: C2270 3.8 Locating Cylinder Head Stud problems ?

Post by splosh » Sun Jul 14, 2019 9:25 pm

Interestingly, I Just found this supplier that shows the stud with a narrow shoulder and one with a wider shoulder
??
https://coventryautocomponents.co.uk/st ... ct_id=1649
Clive
August 1961 Flat floor ots

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#16 Re: C2270 3.8 Locating Cylinder Head Stud problems ?

Post by splosh » Tue Jul 16, 2019 12:12 pm

Update.....
Spoke to SNGB and they are going to get their quality control to inspect the "C2270" cylinder head stud.

However, I have had success and after discovering Coventry Auto Components and speaking to Stuart there yesterday. He measured up both the shouldered studs that he stocks and we decided to go for his "8203" XK Cylinder Head Stud.
It arrived first thing this morning and after cleaning up the plating with some p2000 grade paper it is a perfect fit into the cylinder head.
Also, The thread for locating into the block is perfect too. The following photos show the proof....


Coventry Auto Components "8203" stud.
Image

Stud "8203" after cleaning off the plating with P2000 paper and now a snug fit.
Image

C2270 stud on the left and notice the tapered waist, with "8203" on the right. Surely this tapered waist will affect the studs strength ??
Image

waist measurement of Stud "8203"
Image



against tapered waist diameter of Stud C2270
Image

Outside thread dia of Stud "8203"
Image

against Outside thread dia of Stud C2270
Image

and to which the Stud "8203" is now a perfect fit into the engine block, so hopefully this little episode for me is now over. :salute:
Clive
August 1961 Flat floor ots

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#17 Re: C2270 3.8 Locating Cylinder Head Stud problems ?

Post by mgcjag » Tue Jul 16, 2019 4:41 pm

Hi All....Just had this reply back from SNG..
..I now have a little bit more information on this. We had a supplier for these studs for many years however last year their stock appeared to change. We have now resourced these to an alternative supplier and are happy with our current stock. To the best of my knowledge there should be no affected stock still ‘in the field’.
Steve
1969 S2 2+2 & Building a C type replica

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#18 Re: C2270 3.8 Locating Cylinder Head Stud problems ?

Post by splosh » Tue Jul 16, 2019 5:28 pm

Really, Let me have one and I will tell you if they have changed !!!
Clive
August 1961 Flat floor ots

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#19 Re: C2270 3.8 Locating Cylinder Head Stud problems ?

Post by mgcjag » Tue Jul 16, 2019 6:04 pm

Hi Clive...im just the messenger......what reply did you get....Steve
Steve
1969 S2 2+2 & Building a C type replica

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