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Changing Horses in Mid Stream....

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<div class="ubbcode-block"><div class="ubbcode-header">Quote:]aren't our tappets completely inserted in a hole? [/QUOTE]

Shannon,

Yes, they are. And they should rotate or if they don't, bye, bye cam and lifter. That is why there needs to be a very small radius on the lifter lobe and the lifter base. Just enough to allow it to move around as it goes up and down. Dead flat is dead metal after a short time.

Now these rollers are a completely different concept and the TR6 blocks can be over bored in the lifter galley to allow for bigger lifters. The questions are how much boring can be done, how big of a lifter (widths and height) and will can the geometry of the valve train allow? After that what current production roller lifter would fit in the available space? I'll bet that that there is an international engine using these in a smaller than US V-8's that we aren't even aware of.

I think that I'll call my machinist on Monday with a few questions. I know that he builds engines with roller rockers all day long.

Actually, I have to stop there with a set of cam bearings if they come via UPS tomorrow, so I may have some answers by then.
 
What about hydraulic lifters instead of roller. I've been told by a few more knowledgable than me that my TR8, with hydraulic lifters, is not in the same boat as my TR6 with Solid lifters. With that boat being the extreme need for the proper amount of ZDDP.
 
Shawn,

That may be true, but I'm not sure about the oiling requirements for swapping over to hydraulic lifters. What I mean by that is the design to get the oil to the hydraulics more than anything else.

I like the design of the new hardened Moss lifters with the oil hole and they will be fine for me, if I can ever get a cam, but that is another story.

I'm still going to pursue the roller and hydraulic angle with Bob Mason.
 
No problem. If my parts arrive tomorrow morning, as they should, I'll be there mid afternoon. Or sooner.....

I love this stuff too!!!
 
There are two different style American lifters one with the flat connecting bar like you show and another type were they run in between a flat plate which keeps them from rotating. If the length could be worked out it would be trivial to machine a slot into the head to accommodate the flat plate. Just browsing through a few online catalogs, it seems that 0.84" (Oldsmobile) is the smallest diameter cams easily available. Now I kind of regret letting that junked block go.

Hydraulic lifters would be problematic since there isn't a sufficient flow of oil for them the way our engines are designed.
 
<div class="ubbcode-block"><div class="ubbcode-header">Quote:]Hydraulic lifters would be problematic since there isn't a sufficient flow of oil for them the way our engines are designed.[/QUOTE]

That confirms my previous comment (and fears) about the engine oiling design.

Where is the link for the Olds setup that you found? I'll how it to Bob and see what he thinks about adapting these to my engine. He can also make me custom length push rods in his shop, so that it not a worry if I can get these to work.

I'm just not sure about taking the lifter bores out to .084" + whatever tolerance will be needed for oil and clearance. I don't know, maybe there is enough meat there to do it.

It's getting more interesting as this goes on.....
 
I finally got everything pulled off the engine, save the dizzy and fuel pump. Had to index both the crank sprocket and cam sprocket as both were new and had no index marks. Will wait to get the new cam in next week to make sure of the alignment on the sprocket before I take it off the old cam. Still have to jack the engine and pull the cam through the grill opening (have yet to pull all that down.

All I know is this better work as I do not plan on doing it again.

$houlda had a V8!

Now the question of the day. Since I have some individually tested hardened cam followers coming in, I assume the new (not a regrind) cam has an appropriately hardened lobe to match. That actually is a question I need to ask Uncle Ted (Schumacher).

To top it all off, I savagely chipped the paint on my fender when I lifted the radiator out. It never ends....
 
TR6BILL said:
Since I have some individually tested hardened cam followers coming in, I assume the new (not a regrind) cam has an appropriately hardened lobe to match. That actually is a question I need to ask Uncle Ted (Schumacher).
Click to expand...
I agree about asking Ted ... but my understanding is that the new cam lobes are relatively soft as delivered; which is the point of the run-in procedure. The lobes get burnished and work-hardened under relatively low stress, and wind up being suitably hardened in the right places.
 
Randall, this stuff gets complicated.

On another note, what are the chances of my being able to inspect the rod and crank bearings on my engine with the engine in placed. Can I (or should I) pull the pistons and rods out and mic them? The bearings are Vandeville bearings and have maybe 20K on them. Or is there any other inspection or torquing that I can do to the journals to check them out?
 
Hmmmmm......

I'm not doubting you personally, Randall, but knowing the work that goes into the stamping and progressive die tools that I see being built every day, both working surfaces are always hardened equally to the best of my knowledge.

I'm going to look further into that as well tomorrow. I've already asked three cam sources in my weekend emails, but no answers back yet from them.
 
Brosky said:
Shawn,

That may be true, but I'm not sure about the oiling requirements for swapping over to hydraulic lifters. What I mean by that is the design to get the oil to the hydraulics more than anything else.
Click to expand...

Ahh yes, makes sense.
 
Brosky said:
Hmmmmm......

I'm not doubting you personally, Randall, but knowing the work that goes into the stamping and progressive die tools that I see being built every day, both working surfaces are always hardened equally to the best of my knowledge.
Click to expand...
By all means, check with whoever you trust, Paul. I'm just repeating what I've heard from the likes of Kas Kastner and Greg Solow.

Bill, with that amount of metal "missing", I would want to pull the pistons out and have a look at both the ring areas and the rod bearings. After 20K miles, might be worth replacing them anyway ... ISTR Mr Haynes suggests changing rod bearings every 30K (on a 4cyl TR) as preventative maintenance.

As already noted, hydraulic lifters need pressurized oil for proper operation, not just spray from below (and drips from above) like flat lifters use. Might be possible to drill the block to supply oil to the lifters (from the passages to the cam bearings) but it would be a difficult/expensive operation I suspect.

Hmm, wonder what's in the area between the pairs of lifters ? Might be you could cut a slot in there for the holding plates for rollers ... of course then you'd have to find someone to grind you a roller cam. The lobes are tapered on flat/hydraulic cams, but not on roller cams.
 
Roller cams have a different profile than a flat tappet cam. The cam shaft manufacturer should be able to recommend an equivalent profile.
 
Brosky said:
Where is the link for the Olds setup that you found? I'll how it to Bob and see what he thinks about adapting these to my engine. He can also make me custom length push rods in his shop, so that it not a worry if I can get these to work.

I'm just not sure about taking the lifter bores out to .084" + whatever tolerance will be needed for oil and clearance. I don't know, maybe there is enough meat there to do it.

It's getting more interesting as this goes on.....
Click to expand...

This is the sort of roller I was thinking of

https://store.summitracing.com/partdetail.asp?part=LUN-72400LUN&autoview=sku

To bad they don't have good dimensional drawings of these part at least the total length then it would be easy to sit down an measure the bores and work out how much would need to be machined away.

Incidentally it looks like the top half is pinned to the bottom (roller half) it may well be possible to get the top half made up in different lengths.
 
TR3driver said:
TR6BILL said:
Since I have some individually tested hardened cam followers coming in, I assume the new (not a regrind) cam has an appropriately hardened lobe to match. That actually is a question I need to ask Uncle Ted (Schumacher).
Click to expand...
I agree about asking Ted ... but my understanding is that the new cam lobes are relatively soft as delivered; which is the point of the run-in procedure. The lobes get burnished and work-hardened under relatively low stress, and wind up being suitably hardened in the right places.
Click to expand...
I think it's generally agreed that the lobes on a flat tappet cam as well as the lifters, NEED to be around RC55 or greater to last for very long. They WON'T get any harder during run in. Just more finely polished & mated to their respective surfaces.
D
 
I always of the opine that the more you worked the material by bashing (tongue in cheek)/shot peening the harder it got, but more brittle, kind of like s/s?
 
I don't believe that there is any substitute for proper heating treatment of the materials in question, be it prior or after grinding. The big factor is whether or not the grinding will remove the heat treated area in the process.
 
Bill
when you originally installed the cam and roller rockers etc., did you check for spring binding at all? I reread your other post and didn't see the question asked.

How about it guy's could this be a possibilty?
I know when I put my cam in years back I was instructed to check for this.

This should show up if springs are removed and the coils are shiny where the coils have hit each other I think. Just a thought.........
 
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