CLEVELAND ENGINE TALK

[gerg 10,875]

Fair comment, I was thinking that the actual casting around the lifter bores wasn't as high on the Weezer...
Would a smaller base circle be any different?  Roller cams have higher lift, don't they.?
 

As a general rule, yes they are capable of going higher, especially for a particular duration because they can rapidly open and close the valves with steeper ramps when compared to flat tappets. This is why most people go to a roller. But I have a different reason. I have just wiped another cam, for no apparent reason except for driving the fucking thing.

I love the current grind in it, very well suited to the driving I do. It's a baby at 208/208, 110 lobe and 484 lift. The closest roller I can find is 205/205 110, 510 lift.

I'll take some snaps as I pull the cunt apart and see what the fuck is going on, put it up on my gergwagon thread.

As for wheezor lifter bores, I believe the casting changed when they went factory roller, which was merely a raised boss around each lifter bore to support the dog bones and prevent the lifter body smacking on them as they ride up and down on the flats machined into them. Retro ones with the reduced base circle sit the lifter further down so that this isn't a problem. Maybe the tie-bar type lifters are what they mean?

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[bear351c 10,395]

Yeah, pics would be cool, for the rest of us to learn, as well. 

 

Would lifters in pairs, with a tie bar be easier than dog bones.?  

 

Interesting...... Coil spring bind.?? Rocker ratio??  wait and see.... 

[gerg 10,875]

Yeah, pics would be cool, for the rest of us to learn, as well. 
 
Would lifters in pairs, with a tie bar be easier than dog bones.?  
 
Interesting...... Coil spring bind.?? Rocker ratio??  wait and see.... 

Coils are supposed to be good for at least 0.650, but rocker ratio does get me thinking.... 1.73:1 leverage on a 280 open, 115 seat pressure might be too much for a flat tappet. Still, other mechanics I've talked to at work are also scratching their heads over this one. Particularly since this is the 3rd cam it's eaten in about 75,000 ks. First 2 rounded different lobes each time, so you can rule out a wonky lifter bore. Fucked if I know. As soon as the weather allows, I'll rip into it

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[CHESTNUTXE 7,636]

gerg didnt you just put a small hyd in yur cleveland ?

[gerg 10,875]

gerg didnt you just put a small hyd in yur cleveland ?

Yep, failed after only 6 weeks of driving. Did everything right, still fucked.

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[CHESTNUTXE 7,636]

hmmmm weird,buy a hyd roller kit from rocket ,i know they are expensive but good quality gear.

[gerg 10,875]

hmmmm weird,buy a hyd roller kit from rocket ,i know they are expensive but good quality gear.

I can land a retro kit from Summit for a bit over a grand. Big slog but I'm sick of worrying about flat tappets, special oil, even the way I drive it. Full roller valvetrain means I can use whatever oil I want and forget about this crap

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[CHESTNUTXE 7,636]

I can land a retro kit from Summit for a bit over a grand. Big slog but I'm sick of worrying about flat tappets, special oil, even the way I drive it. Full roller valvetrain means I can use whatever oil I want and forget about this crap

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Have you got roller rockers ?

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[gerg 10,875]

Have you got roller rockers ?

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Got 12 scorpions, need another 4. You can buy individual ones from Summit.

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[CHESTNUTXE 7,636]

ok but dont get stung

[bear351c 10,395]

Apparently scorpion do an adjustable roller rocker for Clevos now. #3224 (I think)

 

 

[gerg 10,875]

Apparently scorpion do an adjustable roller rocker for Clevos now. #3224 (I think)
 
 

Unfortunately, the 12 I have are non-adjustable. No big deal, shim kits are easy to get, once set up correctly should never need to be touched again

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[Boingk 884]

For the guys wiping lobes, are you running an oil with plenty of zinc?

 

I like diesel oils as they tend to have a stack, and most Penrite blends tend to have upper-limit amounts. 

 

 - boingk

[gerg 10,875]

For the guys wiping lobes, are you running an oil with plenty of zinc?
 
I like diesel oils as they tend to have a stack, and most Penrite blends tend to have upper-limit amounts. 
 
 - boingk

This is often a myth these days, I've been reading heavily on this subject and the majority of oils have had the zinc reduced to below 800 ppm, an API requirement for an SJ rating and newer.

Even those that were traditionally known to have good zinc levels such as Shell Rotella (a favourite of hot rodders and the like) have had their zinc levels reduced to the modern accepted levels. ZDDP is becoming hard to find in decent amounts in any except specific vintage or race oils. A good accepted Zinc level for flat tappet engines is around 1500 ppm.

ZDDP attacks cat converters over time, so has been reduced to minimise the effect.

Also diesel oils have increased detergent levels to prevent sludging. These detergents apparently work against the zinc additives by not letting them bond sufficiently with the metal surface. I'm not sure that diesel oils are the best choice for a flat tappet petrol engine.

I did everything I could to make this cam live: moly coat lobes and lifters, comp break-in lube, 2000-2500 rpm run-in for 20 min, dump oil and filter then use Fuchs Titan 20W-60 race oil, which has decent Zinc levels and came highly recommended by Ando76 on here. Note: race oils have very little detergents, so road-going engines can get a bit sludgy in a very short time.

So I'm done worrying about oils. After the 3rd cam in 75000 ks, I'm going to bite the bullet and go full roller. On a daily driver.... Yep!

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[Boingk 884]

5 hours ago, gerg said:

I did everything I could to make this cam live, I'm done worrying about oils. After the 3rd cam in 75000 ks, I'm going to bite the bullet and go full roller. On a daily driver.... Yep!

 

Can't argue there mate.

 

Most Pentrite oils I use tend to boast 1200ppm+ ZDDP levels, which seems decent in my book. I particularly like their HPR30, a 20W-60 weight mineral oil. It might sound antiquated but I ran it in my fully instrumented, Continental-engined aircraft and it was a winner. Didn't discolour, didn't break down with heat, didn't lose oil pressure on hot climbs or hot idle, and allowed me to use full throttle judiciously. Nothing else I tried even came close. And this was with an extended oil drain interval, too!

 

Hope the roller conversion goes well!

 

 - boingk  

[CHESTNUTXE 7,636]

all this talk of roller cams makes me want to grab the low km AU 5.0L with gt40 heads at the wreckers.

[Mr Polson 10,214]

This is often a myth these days, I've been reading heavily on this subject and the majority of oils have had the zinc reduced to below 800 ppm, an API requirement for an SJ rating and newer.

A lot of Penrite oils actually don't meet modern oil specs because of their high zinc levels, the bottles do state this in the writing on the back, something like:
"Rated at SL spec due to high zinc levels, but provides full protection equivalent of SN spec"

[gerg 10,875]

 
Can't argue there mate.
 
Most Pentrite oils I use tend to boast 1200ppm+ ZDDP levels, which seems decent in my book. I particularly like their HPR30, a 20W-60 weight mineral oil. It might sound antiquated but I ran it in my fully instrumented, Continental-engined aircraft and it was a winner. Didn't discolour, didn't break down with heat, didn't lose oil pressure on hot climbs or hot idle, and allowed me to use full throttle judiciously. Nothing else I tried even came close. And this was with an extended oil drain interval, too!
 
Hope the roller conversion goes well!
 
 - boingk  

Yeah Penrite gets a pretty good rap on here, great feedback on your experience with it. Interested in your aircraft capers... I'm a bit of a plane nut, mostly WW2 stuff. Maybe a thread on here?

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[CHESTNUTXE 7,636]

Yeah Penrite gets a pretty good rap on here, great feedback on your experience with it. Interested in your aircraft capers... I'm a bit of a plane nut, mostly WW2 stuff. Maybe a thread on here?

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I use this one on my older engines

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[gerg 10,875]

Well early days yet, but I might have jumped the gun on that cam failure, as in maybe it hasn't failed. I pulled the top of my engine apart today.

 

Bad news: Looks like I might have fucked up with the rockers. Pushrods too long for them. Excessive preload on the lifters could be causing dramas with the hydraulics.

 

Also, one of the rocker bolts had bottomed out in its hole, allowing the rocker to still be loose once torqued. It damaged part of the rocker tip on the end of the rocker as it rotated sideways and the valve tip contacted part of the alloy part of the rocker. I think it will be ok though.

 

Good news, seems like the cam is ok so far. Pulled out 3 lifters and all look beautifully bedded in, like a mirror. I will check the rest of them when I get some pushrods for it and pull the others out to swap them.

 

Either that or shim them up to reduce the preload. I don't have verniers long enough to measure my pushrod checker, but after adjusting it to get about 2/3 of a turn preload, then holding it up next to a stock pushrod, by eye it looks between 60 and 80 thou shorter.

 

So if I shim under the post with a washer of about 0.040" thickness, I should get around 0.060" less preload at the lifter, equivalent to a pushod shorter by this amount, which is what I'm shooting for.

 

I arrived at that figure by backwards calculating the ratio of the rocker, which gives me 1.58:1. So whatever I shim to, multiply that by this ratio and that will give the change in preload.

 

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Tip damage

 

Another one rubbing on the baffle inside a rocker cover

 

Witness marks

[CHESTNUTXE 7,636]

crane do a packet of 030 and sixty thou shims,i used em b4 and worked well

[gerg 10,875]

crane do a packet of 030 and sixty thou shims,i used em b4 and worked well

Well I did the povvo version on one of them so far, got an 8mm flat washer that looked about right (my guess about 0.060), ground flats on each side and chucked it under one of the pedestals. Turned out to be spot-on. Now with the scorpions, preload was exactly as I measured with the checker: around 2/3 of a turn. So all I have to do is carve up 15 more washers to suit the rest. 

I think I know where the excess preload had come from. Just how much has come off the heads is anyone's guess, but I got 0.025 shaved when I got them done, and had been skimmed before that when the engine was done up. So there was anywhere between 30 and 40 thou extra preload over factory.

 

When bolting on the stock rockers, they were pretty worn, so the additional preload would have been taken up by the slop in the rocker pivots. The result was normal preload with worn rockers.

 

Then I go putting on some nice shiny new rollers, and suddenly there is tons of preload, my guess was between 1-1/2 to 2 turns (hard to guess as the lifters kept self-priming when trying to determine preload), in which case is way too much.

 

I think possibly with that much preload, the lifters weren't priming properly, causing noise and clearance issues.

 

Thankfully, I now know that the cam is ok. I pulled the lifters out of one side so far and all are nicely bedded without signs of undue wear.

 

All of them looked pretty much like this one:

 

 

A non-shimmed then a shimmed pedestal:

 

 

 

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[gerg 10,875]

 

 

 

 

A lot of Penrite oils actually don't meet modern oil specs because of their high zinc levels, the bottles do state this in the writing on the back, something like:

"Rated at SL spec due to high zinc levels, but provides full protection equivalent of SN spec"

Yeah I've been reading about zinc levels, and even SL spec might not be adequate. That range was 1000-1400 ppm, then when SM came out it went down to 600-800. You have to go back all the way to SI spec to be certain that you're getting a decent amount of zinc (1400-1600) which these days is unavailable. These levels are really only attainable through using racing oils.

 

But@Boingk's personal account of using Penrite in his aircraft engine gives quite a reassurance that it's a good thing, so that's something to keep in mind. So far using Fuchs Titan 20W-60 (on@ando76's advice) has proven itself to be keeping the cam alive. I have noticed some light sludging in the nooks and crannies on top of the heads though, half expected with low detergent race oils like this.

 

Perhaps a half decent Zinc oil plus a top-up of half a bottle of zinc break-in additive would be good insurance? Fuchs can be a bit hard to find, that's all.

 

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[ando76 4,354]

Fuchs for the win.  If it's a streeter - 1/3 of a bottle of brake in lube with every oil,change helps. Race motors the oil gets dumped every meeting so less of an issue. 

[Boingk 884]

Wow @gerg looks like you caught that in the nick of time. Good work on figuring out the shims, that'll definitely set you up nicely. 

 

For the aircraft, it was a Gardan Minicab built in 1969 and powered by a 1940 model Continental A65-8; an air-cooled 170ci flat four for non aircraftians. It had twin Bendix magnetos and no starter, so I had to hand prop it. Because it was a low winger I stood in front of the prop. Generally started second or third flip, stupidly satisfying!