9 replies to this topic

[PiG]

As per the title really, MPI going out to 1330 with Calver st pistons, ACDodd 11 stud head, guessworks gearbox and xpin nice spec but obviously limited to 85bhp as a maximum with stock ECU.

Possibly at later date specialist components ECU & throttle but will run standard until I feel the need for more power!

Is it worth the extra for ARP over say minispares updated head studs? What about the rod bolts?

[nicklouse]

nowt wrong with the ones you have already.

[PiG]

Good to hear, thank you

[imack]

As above, standard A+ rod bolts and head studs are pretty reliable so long as they're in good condition. I've been using the same set of A+ head studs and nuts on my engines for over 30 years now with no problems. If you feel you want to upgrade any of the bolts I'd upgrade the rod bolts as they're obviously inaccessible once the engines built, head studs can be easily replaced at a later stage if required.

Edited by imack, 07 November 2018 - 08:32 PM.

[Spider]

As a matter of course, it is wise to replace the Rod Bolts at an overhaul, especially in light of what you are doing here.

 

Failure is not at all unheard of and will likely write off everything under the cylinder head.

 

For these reasons, I would strongly recommend replacing the Rod Bolts. I was using the standard ones and the matching nuts happily for many years, but recently, their quality has dropped off and in light of the above, I will now only fit ARP Rod Bolts.

 

In regards to the Head Studs though, the factory original ones were very good. If you have a matching set and they are in good order, I see no reason to replace them. If you do wish to replace them though, there's a lot of dud studs about so beware. I think the Up-rated ones from Mini Spares are OK as are of course ARPs.

[Turbo Phil]

For the cost of some rod bolts why gamble ? I'd fit ARP here, fit and forget.

Phil.

[PiG]

Thanks for all the info, I'll probably err on the side of caution then for the rod bolts and fit some ARP here, use the original head studs and obviously buy two extra for going 11 stud.

[nicklouse]

Thanks for all the info, I'll probably err on the side of caution then for the rod bolts and fit some ARP here, use the original head studs and obviously buy two extra for going 11 stud.

one and a bolt. and don't forget the bolt is not done as tight. and it is debatable if the extras actually help do anything. if the block has not been machined for them there is little to be gained from adding them.

[Retroman]

Make sure the original studs are good they sometimes get stretched,

 

The UNF threads on top should be straight and parallel not like an egg timer

 

Put  straight edge up against them you can tell

 

They only need torquing to a max of 50 Lbft

 

If you are after the original look the bolt behind the thermostat goes to 25 Lbft

 

Some originals were stamped 300, which is inchfeet and painted red, as Spider just discovered from a BMC memo.

 

 

Here's one on a recently completed build I did on a glorgious grey 67 S on an E reg plate

[PiG]

Thank you for the advice, I've read up about the stud and bolt and varying opinions on torque.  I'll use that method to check the head studs too, very useful.

 

Nice touches on the build there Retroman, little things make a difference!