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head rebuilding

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ichthos

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I have a spare head I would like to get rebuilt for my 69 TR6. I would like to have a rebuilt head that works with modern gasoline and will last for a hundred thousand miles. Any suggestions on what I should ask for and why? I am not interested in high performance, just a nice reliable stock head.Thanks for your help.
Kevin
 
I'd go for a "plain jane" rebuild; except for hardened seats for the exhaust valves. Stay away from bronze valve guides, uprated springs, roller rockers and all those other "improvements" and you should be just fine.

Of course regular maintenance is a must; which means keeping the oil changed, the valves adjusted, and occasionally looking for oil flow through the rockers.
 
I do this type of job alot, rebuilding a TR6 head as we speak, and echo Randy's advice for the msot part, I do use bronze guides in all my head rebuilds. Normally what I do in a head rebuild consist of the following.

Labor:
Disassemble
Degrease
Pressure check
beadblast head inside and out
Clean again after blasting
Replace guides and fit new valves
Install hardened exhaust seats
Cut multi angles on all seats
lap valves to confirm seal and seat width
Measure all install spring heights, and then weight springs and set seat pressures
CC combustion chambers and then deck head to customer CR desire
Mask and paint customer's color choice
Assemble

Parts normally used:
New valves
new valve springs
New valve guides
You can mostly clean up your retainer and keppers if in good shape.

Most of the time this decribes what I do, most of the time it's a head that has had no work done in decades, so all this is warranted, some time if more recent work has been done, not all this is needed. Somtimes other issues can add to the work, every once in a blue moon I'll get a head that has been valve jobbed to death in its life, and it may need new intake seats as well, but this is somewhat rare. This type of work varys greatly in quality and what a shop is actually doing in the rebuid process, in short you get what you pay for.
 
Hap's list is pretty much what I had done to mine 5 years ago.

Like mentioned by Randall and Hap, I only had the exhaust seats installed. Besides the normal reasons I did it for two other reasons as well. One is that I do not like how close the seats fit when both are done. To me it does not leave enough of the head material between them. And only doing the exhaust seats allowed for seats that are slightly heavier. True it would make it difficult or even impossible to do intake seats later but it is a sacrifice I was willing to make.
 
That is all (except for shaving down to 9.5 to 1) what was done to my head when the engine was completed. Spring were matched to the cam recommendation for pressure.

No roller rockers for me.
 
There's no reason to ever do intake valve seats, unless the head has had a bunch of valve job in it's life and you have some serious valve recession, there's no heat on that side, ulneaded gas does not even phase the intake valve seal. The exhaust, well thats another case altogether, it was never designed to run on uneaded fuel on a cast iron seat and that where all the heat is, I don't see exhaust valve seat recession being as big a issue as often stated, it's more about valve seal, once the cast iron seat has been compromised over time by hotter burning unleaded gas it no longer seals very well, we discoverd this years ago thru leak down testing, every head I do gets hardened exhaust seats, unless it already has them. As for a the seats on the TR6 heads being close together yes that is a issue, but a good head shop knows what to do there, we run into the same thing with MG A series heads, you need cut and install one seat first, then install a slightly shallower seat for the second valve, that way you have 360 degrees press fit on both seats.
 
DSCF0023.jpg
 
Ohhhh, that's scary looking. Looks like #2 is bad also. How many were sunken across the entire head, Randall?
 
That's actually #4, which was the worst off. But all of the exhaust valves showed substantial recession. If you look closely, #4 intake has started to sink as well.

I knew it was happening, but didn't want to take the car off the road. It was literally so bad that #4 wouldn't run, because the exhaust valve was not coming above (or below, depending on your point of view) the surface of the combustion chamber, making it effectively closed all the time.

But I don't think it was from unleaded fuel, especially since that head did have hardened exhaust seats. Most likely explanation was trying to run "racing" valve springs on the street.

Here's a close-up
DSCF0023_reduced.jpg
 
Is there any problem of having a head rebuilt and then have it sit for years? Also, what would be a reasonable price to have the work that Hap mentioned?
Kevin
 
Hard to say cost Kevin, as the condition of the head is another factor
 
ichthos said:
Is there any problem of having a head rebuilt and then have it sit for years? Also, what would be a reasonable price to have the work that Hap mentioned?
Kevin
Click to expand...

There are a few shops mentioned on the forums that I would trust to do work for me. Especially to meet your long mileage wishes. For example; I have never heard a bad word about Hap's work. And there is the shop Brosky and others go to.

To answer your questions, give then a call and find out. A head is not difficult to ship so the location would not be critical.
 
Hap is one of us and I'd support him if at all possible. I did not know of him at the time that I did mine, or I probably would have gone that route. I'm very happy with mine, but I try to support our own as much as possible.
 
ichthos said:
Is there any problem of having a head rebuilt and then have it sit for years?
Click to expand...

I can't see that it would be any problem, assuming you store it in a reasonable place. Not out in the rain or anything :smile:.
 
ichthos said:
Is there any problem of having a head rebuilt and then have it sit for years?
Click to expand...
Only problem would be rust. Clean metal will rust very quickly, even stored indoors. Give it a coat of your favorite preservative oil, it should be fine.

FWIW I've been trying out "Blaster Corrosion Stop" (from the same folks that make PB Blaster) and it seems to work well.
https://www.blastercorporation.com/Corrosion_Stop.html
Around here, Home Depot & Wally mart carry it, so it's also easy to find.
<div class="ubbcode-block"><div class="ubbcode-header">Quote:] Also, what would be a reasonable price to have the work that Hap mentioned?[/QUOTE]
Seems like we had a thread on that not too long ago, and someone mentioned $1500. That's assuming you R&R the head yourself, and carry it into the machine shop.
 
Thanks for all the information. I do prefer to do my business with supporting vendors and individuals on the forum. Unfortunately this time I think it would be costly since I am on the West coast. I will check out shipping charges later once I weigh it. After the money I have spent lately, I also have to slowly build up my reserves. Thanks again,
Kevin
 
Supporting vendors are great, but there is actually nothing special at all about these heads. Any competent machine shop should know all the things that have been mentioned; and there is also something to be said for doing business locally.

Since the cost is mostly labor, you might also be able to find someone who is short of work, and willing to make a deal to get your business. Some people feel that working at $30/hour is preferable to standing around doing nothing with a $75/hour sign on the wall.
 
ichthos said:
Is there any problem of having a head rebuilt and then have it sit for years? Also, what would be a reasonable price to have the work that Hap mentioned?
Kevin
Click to expand...

No as long as it pressure checks good, no cracks, and is not extremely rusty.

He, he, good machine shops with nothing to do, thats funny :smile: any good shop always has a backlog, a specialty shop like mine even a deeper backlog, I stayed 8 months to a year back on complete engine rebuilds since I opened my doors, 11 years ago, on smaller jobs, like engine component work, cylinder heads, SU carb rebuilding, more like 2-4 months backlog and I'm not alone, most any of us in the specialty LBC field will have deep backlogs. Some local machine shop will do good overall rebuilding, like the Shop Brosky used, but alot of them re production minded, meaning patch it up and get it out the door. Alot of the time the low man on the totem pole in some machine shops is the guy doing vale jobs, he banginghtem out, no where near the work list I listed above, using stone grinders on the seat, not replacing the exhaust seat, just putting one angle on the seats, sure it only cost $100-200, but you didn't get much for your money. I seen this going on at lots of machine shops most of my adult life, it's real hard to find folks that do really good work, most shop are too production minded and just wanted to get the job out the door, they are too geared for the local auto repair shop, who needs it quick and just wants the minimum amount of work done, which normally means a short term fix. I'm not sayng there are not good local machine shops in a given area, just for the novice hobbist it sometimes pays to do your research, and sending a engine or components off to well known specalist is not that big of deal, a TR6 head easily UPS ships. I often surpised at the places I get jobs from, right now in the shop we're rebuilding three engines, A TR6 from Chatanooga TN, a MG 1275 from Ann Arbor MI, and a MGB from from Wasilla, Alaska, the next 4 engines to do for me are from TX, FL, PA, and DC.
 
Finding quality workmanship has been one of my biggest frustrations with my LBCs. I am almost done restoring a bugeye, and one of my biggest challenges has been finding quality workmanship. Spending more money has not always insured better quality work, either. Finding this forum, and help from members was the turning point for me in finally finding quality work.
Kevin
 
I was lucky with my local shop. First he gives a 1 year guarantee on his work. And second he was entirely open to learning about LBC's and which parts are better. Third, he was willing to discuss his thoughts with me so together we could determine the best path.
 
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