1964 TR4 - Part 8 - Replacing The Valve Guides 

Oh, yeah, nothing wrong with resurfacing them. I figured some of these had pretty deep wear and probably some of them might need bushings and at a price of $12 per rocker with a new bushing it might be cheaper to get new ones.

I know they can be refaced, but I doubt it would be cheaper than new ones. They are pretty cheap.

I have never replaced guides, thinking it is machine shop work. But your video shows it to be quite easy. I recall, though, recommendations to put the guides in the freezer first to shrink them before pressing in. Obviously you did not need to do this. thanks once more. John on the farm in Manitoba with TS 394 LO

ya these ones are easy but many are not . I do alot of air cooled vw heads they are a pain I have to drill them out to a shell (special drill bit ) and then drive them out THEN to put new one in I have to heat the head to 300 degrees freeze the guides wipe on some white lead and quickly drive them in with a air driver then ream .

These are the steel ones Mike, they are pretty easy to install and never required rimming after. I always check the valve play to make sure that it is within tolerance.

Happy New Year Keith! Yes, they will dip the head and magnaflux it. The block I will clean myself and yes, also new cambearings are in order. This is the only Triumph engine that I know with cambearings.

Yes, that is part of their process. They caught a crack on a TR6 head recently which I missed. So they saved me money

I am not sure if all valve guides are like that, but all the engines I know are this way. Not only Triumph.

The parts are not expansive. I mean not more expensive than the parts for any other car. For us in Canada though the shipping and duties are what makes them expensive as everything comes from the US or UK. Yes, you can put high power coil in a TR. In fact the later TR6 uses a high power coil, which is basically a coil with lower resistance, that produces twice the Amps when connected to 12v. And since that amount of power is only needed during the starting of the engine, most of the time the coil is connected through a resistor (load) in order to reduce the voltage to 6v and only during the cranking the load is bypassed and 12v are going straight to the coil. The usual distributor upgrade most of the owners like is electronic ignition, which eliminates the old fashion points. Very easy to convert.

No, it is the same as the other ones. What I think happened is it bent slowly a little bit at a time and the valve lash was readjusted multiple times to compensate. and of course every time it got adjusted the rod got bent more because once it is bent a little it is easy to bend more. This catch 22 continued until the rod curved to a point where it hit the wall and couldn't bend anymore. That's when the lash could be adjusted and kept at somewhat correct tolerance and the engine kept running somewhat normally. I think that was what was happening with my first Spitfire engine. I kept adjusting number 1 valve and it kept getting out of adjustment. It happened 3 times in one day on my last drive for that year. Over the winter I rebuilt my MK3 Spitfire engine and used that one for my MK2, so the old one never got taken apart. But I am sure that's what was happening. The pushrod was getting bent more and more and I was just chasing my tail trying to adjust the lash.

Guides with no shoulders are very common. There is no pressure on either side of the guides and the only reason why one would "slip" is if it is too tight and creates friction with the valve, but in that case a "slipping" guide is your least problem. And yes, the factory ID is perfect on the steel guides, they do not require rimming. The manganese-bronze ones are the ones that might change ID during installation. Yeah, I think the previous rebuild was due to a snapped tensioner pivot , which somehow lead to a bent push rod, which they probably strengthened and reused. But once bent the push rod weakens and even after straightening it it continues to bend. So I suspect that after the rebuild it just slowly took that S-shape and someone constantly readjusted the valve lash, which is why the engine was still running. I had that experience with my first Spitfire engine. The number 1 valve kept getting bigger and bigger gap even though I constantly adjusted it. I had no experience at the time and couldn't figure out why. Then I got another engine and rebuilt that as it was 1280cc vs. 1147cc for my old one, so I never took the old one apart. But I am sure that if I take it apart I will find an S-shaped push rod :)

Yeah, I can see that in the video, but I don't think it is a crack. I will check the block later today. Thanks

Yes, I am getting hardened seats for the exhaust valves and all new valves so everything will need to be lapped at the machine shop

That's a really good point, totally hadn't occurred to me. Paul, USA

Oh, that is great, thank you! It is quite a trip though, but I will have that in mind if I ever end up in that area. Thank you!

I was in Toronto a few weeks ago I could have dropped it off but I didn't think of it.

I read many articles and opinions about that. My opinion is that ideally they should be changed, but not because they stretch when torqued. They should be changed because they stretch when overtorqued and you never know if someone overtorqued them in the past. The factory torque is calculated to be as close as possible to the stretching point without getting over. The reason is that once the metal starts stretching it weakens so you don't want to get to that point. Again, it is only my opinion after reading other people's opinions and I might be wrong. For TR4 engines the torque is 100ft/lbs I believe and the possibility that someone overtrqued them in the past is pretty slim so I always reuse them. Never had an issue so far.