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MG TD TF 1500 - Cylinder head nuts

A simple question: should the cylinder head nuts have washers under them or not? I've seen them both ways, and I'm not sure which is right, or even if it matters. Thanks--
S Maas

Yes. And you should use hardened (grade 8) washers.
Kevin McLemore

Thanks. It seemed to me that washers should be used, as in any such application, but because the car came without them and I see others without them, there might be some reason not to.
S Maas

Hate to disagree, but you should only have washers under the head nuts if you are running an aluminum Laystall Lucas head. The standard iron head should not have any.

Tom Lange
MGT Repair
t lange

Hmm. You're more of a T-series expert by far than I, Tom, so I'll defer to your advice. But I am curious why one would not use hardened washers in any circumstance - iron or alloy. Wouldn't they offer greater stabity to the head torque over time? I've always we used them and not had issues. Or is this a matter of 'historically correct'?
Kevin McLemore

Unless the head is properly (and perfectly parallel) relieved for the washers, you may run into an uneven clamping concentrating force on a fraction of the intended area. Since no washers were used originally, using them now could lead to problems.

Warmly,
dave

Dave Braun

Only special hardened washers are parallel ground for perfect symmetry, so hardware store washers are not suitable, even if they are hardened.

Washers were often put under head bolts when the head had been skimmed to such a degree that the nut bottomed out on the stud threads. My ARP head studs with 1/4" extra threads takes care of that (see mgtrepair.net).

Tom Lange
MGT Repair
t lange

I was away for a while, but in any case, thanks for your comments. I guess the bottom line, as we yuppies say, is that washers were not used originally, so for whatever reason, it seems best to do without. The original reason may be lost to history, but that doesn't mean it doesn't exist.
S Maas

Tom, I was just looking in AKD 834, Section R, MKII and spotted something: Engine .. Flat washers - cylinder head nuts, Qty 10, Part No. AJJ605, Fin. at 17028. Bud
Bud Krueger

I had my head at Parrys in Sydney a couple of years ago to fit hardened inserts for use with unleaded & because it has had 143 thou removed by a PO, the head reconditioners provided "special hardened washers parallel ground for perfect symmetry" (presumably), for use under the nuts. Hate to disagree with those who disagree but if using anything but Tom's extra length studs then purpose designed washers are indeed appropriate IMHO. I have them & because of my skinny head (CR 10.1 to 1) I will continue to use them. Cheers
Peter TD 5801
P Hehir

Bud - those washers were recommended for racing engines, where the head has been skimmed. When a lot of cylinder head thickness is removed (more than 1/16") the head stud threads are no longer adequate - nuts simply run out of threads. Special Tuning manual - "Use 1/8" thick by 3/4" O.D. washers under cylinder head nuts (to correct reduced thickness)."

That's why on my ARP head studs I have added 1/4" of thread, to compensate where the head has been skimmed aqd/or re-surfaced multiple times over the years. Racers like Manley Ford use my head studs because of this feature, and because of the much-improved quality.

Aluminum heads would always need washers, as the nuts would gouge the softer head.

Tom Lange
MGT Repair

t lange

Perhaps it might have been better for me to say that basically standard engines that have NOT been modified or where there is no significantly reduced head thickness, have no need for washers under the head studs.

Where the head thickness has been significantly reduced, it is desirable to fit them, or obtain a set of my longer head studs. As Peter point out, unless washers are the proper type and properly manufactured (parallel ground), they can cause problems.


Tom Lange
MGT Repair
t lange

Tom, the data in Section R of AKD834 really seems to indicate that the M.G. folks considered the .060" removed from the MKII head justified the use of flat washers under the cylinder head nuts. That was the case up until Engine 17028, the point at which TD/C became TD3. The head studs were the standard TD2 studs. Bud
Bud Krueger

The nuts on my head have about 1 to 1.5 threads exposed above the nuts and no washers. Apparently my head has never been cut if their the original size studs. PJ

Paul S Jennings

This thread was discussed between 15/09/2014 and 09/11/2014

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