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Lifter failure?

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Darth V8R Avatar
Darth V8R Vance Navarrette
Beaverton, Oregon, USA   USA
1980 Triumph TR8 "Wedgie"
In reply to # 1491970 by darrellwalker
In reply to # 1491905 by Darth V8R
I rotate the engine to maximum lift on a valve and then use feeler gauges to check the coil clearance.

Hi Vance,

How do you deal with the lifter bleed down?

-Darrell

Darrell:

You have point. The last time I did it was with a solid lifter cam (My TR6).

On my Chevy, I could adjust the rocker to get the desired lift (as measured by my vernier caliper). I rotated the engine, measured the valve spring height before and after the spring compressed, then rotated the adjuster to compress the spring further. This was for a LT4 hot cam installation. But no adjusters on the Rover V8. Crap.

Thinking back to the cam installation on the TR8, I recall now that I did not have a good way to do this check for that reason. I recall looking up the installed height and the solid stack height, and then using the rated lift to determine the remaining margin. I divided the remaining number by the number of coils which gave me the gap between coils. I remember thinking that was a very crude way to do it. The problem with doing it that way is it makes a lot of assumptions (heads haven't be shaved, ignores manufacturing tolerances, etc). The best way to do it is to measure it, but I recall now doing it on paper only.

Found the specs for the stock springs; Installed height is 1.575". Solid height is 1.020". This means that the spring will tolerate an absolute maximum lift of 0.505" before it stacks solid. The cam I used had a rated lift at the valve of 0.451" - leaving 0.054" before it stacked solid. Divide by 6 (the number of coils) and you get 0.009" between coils. Right on the edge. This agrees pretty well with Todd's assessment of 0.470" lift before things start breaking.

You can use a solid lifter, although not many people would have one in their tool kit. An adjustable push rod will serve as well - available from Summit. Either of these will let you measure the space between coils.

OK, if you want to go for more lift, what do you do? As Todd stated, you can machine for Chevy valve springs which will really open up the range of cams. Another option is performance springs. Kent Cams makes a nice set of springs that will tolerate more lift. They are double valve springs, which is the only way you are going to get more lift without machine work. The VS43 springs will handle 0.630" lift before stacking solid, so figure roughly 0.550" lift before you need to go to the Chevy valve spring option. That is a whale of a lot of lift for a street engine. I seem to recall thinking that at 0.500" lift, the keeper would hit the valve guide. It has been three years, so the details are way fuzzy.

This is from a guy who ignored the factory's recommendation and did a 0.060" overbore during the rebuild, so I definitely took things beyond safe when I did my engine. It hasn't blown up yet, but I don't have very many miles on it either. Maybe you should be talking to a guy who doesn't flirt with disaster quite so much. eye popping smiley

Vance



1980 Platinum Metallic TR8, navy blue interior
Bare metal respray, Crower cam, raised compression
ported heads, modified Zenith carbs, 0.060" overbore

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darrellwalker Darrell Walker
Vancouver, Washington, USA   USA
1966 Triumph TR4A "Christy"
1981 Triumph TR8 "Kate"
Hi Vance,

Thanks for the ideas. Since I'll need to pull the head to check that the valve isn't bent or binding, I can use my press to check the lift and clearance. Just to clarify, my heads were supposed to be modified to work with the lift of the TQ20 cam, so it should all be good.

I pulled the rest of the lifters, for Sesame Street fans, "which one of these things is not like the others?"



Darrell Walker
66 TR4A IRS-SC CTC67956L
81 TR8 SATPZ458XBA406206
Vancouver, WA, USA


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darrellwalker Darrell Walker
Vancouver, Washington, USA   USA
1966 Triumph TR4A "Christy"
1981 Triumph TR8 "Kate"
Starting to get to critical mass on the replacement parts. The engine disassembly isn't keeping up, much easier to spend money than get time. Additionally, I think I've decided that I should pull the engine. One reason is that I was oil leak free for about a year after the rebuild, but since then it has started to leak, perhaps the rear main seal. It isn't a terrible amount, but enough to be annoying, and there won't (hopefully!) be a better opportunity. I also figure there must be quite a bit of metal circulating in the oil considering how much the lifter was ground down. Hopefully the oil filter took care of it, but it might make sense to at least check the bearings, or even just replace regardless. I also need to decide if I'm pulling the head before or after I drop the engine. I might do it before so that I can check out the clearance, and get that addressed if there is a problem.



Darrell Walker
66 TR4A IRS-SC CTC67956L
81 TR8 SATPZ458XBA406206
Vancouver, WA, USA

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Darth V8R Avatar
Darth V8R Vance Navarrette
Beaverton, Oregon, USA   USA
1980 Triumph TR8 "Wedgie"
In reply to # 1492601 by darrellwalker Starting to get to critical mass on the replacement parts. The engine disassembly isn't keeping up, much easier to spend money than get time. Additionally, I think I've decided that I should pull the engine. One reason is that I was oil leak free for about a year after the rebuild, but since then it has started to leak, perhaps the rear main seal. It isn't a terrible amount, but enough to be annoying, and there won't (hopefully!) be a better opportunity. I also figure there must be quite a bit of metal circulating in the oil considering how much the lifter was ground down. Hopefully the oil filter took care of it, but it might make sense to at least check the bearings, or even just replace regardless. I also need to decide if I'm pulling the head before or after I drop the engine. I might do it before so that I can check out the clearance, and get that addressed if there is a problem.

Which cam did you end up with? Please post the specs...

Thanks,

Vance



1980 Platinum Metallic TR8, navy blue interior
Bare metal respray, Crower cam, raised compression
ported heads, modified Zenith carbs, 0.060" overbore

darrellwalker Darrell Walker
Vancouver, Washington, USA   USA
1966 Triumph TR4A "Christy"
1981 Triumph TR8 "Kate"
In reply to # 1492620 by Darth V8R
Which cam did you end up with? Please post the specs...

Thanks,

Vance

I went with the 50231.

-Darrell



Darrell Walker
66 TR4A IRS-SC CTC67956L
81 TR8 SATPZ458XBA406206
Vancouver, WA, USA


Attachments:
camtag50231.pdf    33.7 KB

Darth V8R Avatar
Darth V8R Vance Navarrette
Beaverton, Oregon, USA   USA
1980 Triumph TR8 "Wedgie"
In reply to # 1492621 by darrellwalker
In reply to # 1492620 by Darth V8R
Which cam did you end up with? Please post the specs...

Thanks,

Vance

I went with the 50231.

-Darrell

That will be a sweet street cam, noticeable rumble.

One step above the one I installed. I am sure it will perform for you.

I lubed the daylights out of mine, then broke it in for 20 minutes with comp cams Break in additive (ZDDP) at 2000 RPM. So far no issues.

BTW, you are right across the river from me. We need to get together and swap some war stories.

Vance



1980 Platinum Metallic TR8, navy blue interior
Bare metal respray, Crower cam, raised compression
ported heads, modified Zenith carbs, 0.060" overbore

darrellwalker Darrell Walker
Vancouver, Washington, USA   USA
1966 Triumph TR4A "Christy"
1981 Triumph TR8 "Kate"
Disassembly continues at a slow pace. Got the head off on the side where the lifter failed. Haven't measured the clearance yet, but here is a closeup of the spring setup. Without measuring, there looks to be plenty of clearance.



Darrell Walker
66 TR4A IRS-SC CTC67956L
81 TR8 SATPZ458XBA406206
Vancouver, WA, USA

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Darth V8R Avatar
Darth V8R Vance Navarrette
Beaverton, Oregon, USA   USA
1980 Triumph TR8 "Wedgie"
In reply to # 1493731 by darrellwalker Disassembly continues at a slow pace. Got the head off on the side where the lifter failed. Haven't measured the clearance yet, but here is a closeup of the spring setup. Without measuring, there looks to be plenty of clearance.

Those are definitely not stock valve springs. They have a friction damper inside the spring. Based on the photo, it appears that limiter might be the damper, not the spring. It also appears that the valve spring pockets have been machined to accept taller springs.

Vance



1980 Platinum Metallic TR8, navy blue interior
Bare metal respray, Crower cam, raised compression
ported heads, modified Zenith carbs, 0.060" overbore

darrellwalker Darrell Walker
Vancouver, Washington, USA   USA
1966 Triumph TR4A "Christy"
1981 Triumph TR8 "Kate"
Checked clearances, no problems there. I lifted the valve 0.538 (0.478 + 0.060 for clearance, the valve lift of the TQ20 cam), and had at least 0.020 between the spring coils, and just under that on the dampeners. I also checked clearance to the guide, and it is at least 0.564 (it is a little more, because the retainer is dished a little more than where I measured.

The valve is also straight, and moves freely in the guide. You can also see that oil seals were added to the guides (the 3.5 never had them).

So nothing there to blame for the failure. I also did the break in as prescribed, and 15 of the 16 lifters and lobes are fine. So absent some defect in that one lifter or lobe, I have no explanation for the failure.



Darrell Walker
66 TR4A IRS-SC CTC67956L
81 TR8 SATPZ458XBA406206
Vancouver, WA, USA

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Darth V8R Avatar
Darth V8R Vance Navarrette
Beaverton, Oregon, USA   USA
1980 Triumph TR8 "Wedgie"
In reply to # 1493975 by darrellwalker Checked clearances, no problems there. I lifted the valve 0.538 (0.478 + 0.060 for clearance, the valve lift of the TQ20 cam), and had at least 0.020 between the spring coils, and just under that on the dampeners. I also checked clearance to the guide, and it is at least 0.564 (it is a little more, because the retainer is dished a little more than where I measured.

The valve is also straight, and moves freely in the guide. You can also see that oil seals were added to the guides (the 3.5 never had them).

So nothing there to blame for the failure. I also did the break in as prescribed, and 15 of the 16 lifters and lobes are fine. So absent some defect in that one lifter or lobe, I have no explanation for the failure.

Very reassuring that your machinist knew what he was doing. OK, so all of that is ruled out, and if you did the break-in and therefore know it was done properly, then all that is left is a manufacturing defect of some sort. Disappointing.

A buddy of mine ruined two cams in his 1972 Mustang - the first one he didn't break in, and when he installed the second and told me that he had, he stated that he had broken it in properly. I asked him "Great! What kind of assembly lube did you use?" "What's assembly lube?" he replied. Needless to say the second cam also failed very quickly. The third cam he installed he did it all correctly, and never had a problem. This is why I always ask.

It will be interesting to see what the cam lobe looks like.

Great work so far, keep us posted.

Vance



1980 Platinum Metallic TR8, navy blue interior
Bare metal respray, Crower cam, raised compression
ported heads, modified Zenith carbs, 0.060" overbore

darrellwalker Darrell Walker
Vancouver, Washington, USA   USA
1966 Triumph TR4A "Christy"
1981 Triumph TR8 "Kate"
The engine has left the bay!



Darrell Walker
66 TR4A IRS-SC CTC67956L
81 TR8 SATPZ458XBA406206
Vancouver, WA, USA


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Darth V8R Avatar
Darth V8R Vance Navarrette
Beaverton, Oregon, USA   USA
1980 Triumph TR8 "Wedgie"
In reply to # 1494205 by darrellwalker The engine has left the bay!
Darrell:

Curious as to why you are dropping the engine. Is it necessary for a cam change, or are you planning bigger and better things? When I did my cam change, the engine was out of the car, so I don't know if you can change a cam without dropping the motor. I would have said that you could after removing the radiator, but perhaps not.

Also, is that an aluminum PS pulley I see?

Vance



1980 Platinum Metallic TR8, navy blue interior
Bare metal respray, Crower cam, raised compression
ported heads, modified Zenith carbs, 0.060" overbore

darrellwalker Darrell Walker
Vancouver, Washington, USA   USA
1966 Triumph TR4A "Christy"
1981 Triumph TR8 "Kate"
In reply to # 1494227 by Darth V8R Darrell:

Curious as to why you are dropping the engine. Is it necessary for a cam change, or are you planning bigger and better things? When I did my cam change, the engine was out of the car, so I don't know if you can change a cam without dropping the motor. I would have said that you could after removing the radiator, but perhaps not.

Also, is that an aluminum PS pulley I see?

Vance

Hi Vance,

You are correct, you don't have to remove the engine to change the cam. Two reasons I chose to do so. First, for about the first year after the rebuild I was oil leak free. But about a year ago it started leaking from the rear of the engine. Not enough to be a concern, but enough to be annoying. So I figured this would be the best time to investigate that. I'm also a little worried about what all of that ground up lifter and lobe might have done inside the engine. I didn't see any metallic evidence in the oil, but I want to pull the caps and check the bearings. I'll probably just replace them anyway, even if they look OK.

Yes, it is an aluminum PS pulley. The original one had a pretty bad bend, so I went for the bling.

-Darrell



Darrell Walker
66 TR4A IRS-SC CTC67956L
81 TR8 SATPZ458XBA406206
Vancouver, WA, USA

Darth V8R Avatar
Darth V8R Vance Navarrette
Beaverton, Oregon, USA   USA
1980 Triumph TR8 "Wedgie"
In reply to # 1494233 by darrellwalker
You are correct, you don't have to remove the engine to change the cam. Two reasons I chose to do so. First, for about the first year after the rebuild I was oil leak free. But about a year ago it started leaking from the rear of the engine. Not enough to be a concern, but enough to be annoying. So I figured this would be the best time to investigate that. I'm also a little worried about what all of that ground up lifter and lobe might have done inside the engine. I didn't see any metallic evidence in the oil, but I want to pull the caps and check the bearings. I'll probably just replace them anyway, even if they look OK.

Darrell:

Interesting. Before I rebuilt my engine I bought a couple books on the Rover V8 engine, in addition to the TR8 ROM. There were several suggestions in the books that went beyond the procedures in the ROM. One of them related to the rear main seal installation. It was advised that the rear bearing cap, which holds the seal, be installed with sealant such that the sealant visibly extruded when the bearing cap was tightened down. I used non-hardening Permatex form-a-gasket. Took me a couple of tries to get it right. Apparently the seal is not the most likely source of leaks, rather it is seepage around the bearing cap.

I also used the Permatex on the water pump, lifter valley, differential, and sump gaskets (after carefully straightening the sump lip, which had been badly deformed by over tightening).

It has been almost three years now, and my garage floor is still clean. First time I have had a British car that didn't leak.

My DPO had used the later composite head gaskets, which lowers the compression ratio and thus performance. I went back to the original steel head gaskets. One of the books recommended omitting the outermost row of head bolts. Apparently on high mileage engines the steel gaskets fail, and do so on the edge closest to the lifter valley due to uneven clamping forces on the head. Rover later completely removed the outer row of head bolts which cured this issue. Not wishing to look like I forgot something, I installed the outermost fasteners, but only torqued them to 25 lb-ft. I also used ARP fasteners that were 1/4" longer than the original bolts, in order to engage more of the threads in the block.

Enough rambling. I am enjoying the story of your journey, so please keep the posts coming.

Vance



1980 Platinum Metallic TR8, navy blue interior
Bare metal respray, Crower cam, raised compression
ported heads, modified Zenith carbs, 0.060" overbore

darrellwalker Darrell Walker
Vancouver, Washington, USA   USA
1966 Triumph TR4A "Christy"
1981 Triumph TR8 "Kate"
Hi Vance,

In reply to # 1494408 by Darth V8R Interesting. Before I rebuilt my engine I bought a couple books on the Rover V8 engine, in addition to the TR8 ROM. There were several suggestions in the books that went beyond the procedures in the ROM. One of them related to the rear main seal installation. It was advised that the rear bearing cap, which holds the seal, be installed with sealant such that the sealant visibly extruded when the bearing cap was tightened down. I used non-hardening Permatex form-a-gasket. Took me a couple of tries to get it right. Apparently the seal is not the most likely source of leaks, rather it is seepage around the bearing cap.

Well, I got the engine and transmission separated, and it isn't the rear of the engine leaking, but rather the front of the transmission. I did use sealant on the rear cap, though I can't congratulate myself too much, because I'm also responsible for the gasket on the front of the transmission. I didn't use any sealant on that gasket, but I suspect I should, it was quite oily looking.

You can see a smear of the sealant on the right side, also the JB Weld that I used to make sure the cam plug didn't leak (it was leaking there, too).

I'm still going to drop the pan to make sure it is all cleaned out, but now I'm rethinking if I should bother with the bearings.

In reply to # 1494408 by Darth V8R My DPO had used the later composite head gaskets, which lowers the compression ratio and thus performance. I went back to the original steel head gaskets. One of the books recommended omitting the outermost row of head bolts. Apparently on high mileage engines the steel gaskets fail, and do so on the edge closest to the lifter valley due to uneven clamping forces on the head. Rover later completely removed the outer row of head bolts which cured this issue. Not wishing to look like I forgot something, I installed the outermost fasteners, but only torqued them to 25 lb-ft. I also used ARP fasteners that were 1/4" longer than the original bolts, in order to engage more of the threads in the block.

I've done the same. One of my first jobs when I got the car was to replace the head gaskets, as they were leaking from the top into the valley.

-Darrell



Darrell Walker
66 TR4A IRS-SC CTC67956L
81 TR8 SATPZ458XBA406206
Vancouver, WA, USA


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