C2270 3.8 Locating Cylinder Head Stud problems ?

[splosh]

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 ??

[abowie]

I'm sure you know this and have fitted it correctly, but just checking 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.

[splosh]

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...

[splosh]

Incidentaly, does the ARP Studs have the shouldered stud also in their kit ???

[MarkRado]

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...

[288gto]

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

[abowie]

Incidentaly, does the ARP Studs have the shouldered stud also in their kit ???

XKS sell them and at a reasonably comparable price.

[mgcjag]

Just for info i have flaged this with SNG as they have been mentioned above a few times.......Steve

[splosh]

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..

[mgcjag]

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

[splosh]

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.

[splosh]

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.

[265bhp]

I highlighted exactly this issue with SNG around 18 months ago....!, that is not impressive

[splosh]

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.

[splosh]

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

[splosh]

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.


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


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


waist measurement of Stud "8203"




against tapered waist diameter of Stud C2270


Outside thread dia of Stud "8203"


against Outside thread dia of Stud C2270


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.

[mgcjag]

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’.

[splosh]

Really, Let me have one and I will tell you if they have changed !!!

[mgcjag]

Hi Clive...im just the messenger......what reply did you get....Steve

[splosh]

Hi Steve,
The answer I received was as stated...
Quote...
"Spoke to SNGB and they are going to get their quality control to inspect the "C2270" cylinder head stud."

Amazed they have sorted this problem in a matter of moments. That's why I would like to see what they are offering for "C2270" now.
Caveat Emptor