3.4 Lubrication Issues

[87SC/SS]

Hey Guys,

I'm running into a very annoying and expensive issue. I've rebuilt my 3.4 for my 94 Camaro twice. The first time I used a Crane PMax 260 and the car ran for about 4000 miles. It was pretty powerful at first but then started losing power and we couldn't figure out what it was until I started hear a bunch of valve clatter because the lobes on cyls 3 and 4 were wiped out. I was using Mobile 1 at the time and was told that new oils don't have enough zinc to run in engines with performance flat tappet cams. So I rebuilt it a second time and ran the recommended Shell Rotella 10w40 and used an Edelbrock cam instead. It ran for another 4000 miles and I started noticing a serious drop in power, almost like it wasn't getting any timing advance. I checked it with a Snap-On scanner and the computer was hearing a knock. I figured it was a tuning issue because I couldn't hear it so I cranked up the pressure a couple of psi on the AFPR. Then I heard the knock about a week later. The cam is fine but the crank journals for all cyls were completely wasted; much worse at the front of the block and not so bad at the back. We brought the block to the machine shop and went over it with the guys there. We can find nothing wrong with the lubrication system. There was no garbage in the oil passages and when it was running had plenty of pressure (40psi @idle). I'm not a newbie with engine building, I've built a few small blocks and even rebuilt outboard motors and they all ran great. I think I'm just jinxed with 60* V6's. We're at a total loss and I'm into this thing for almost $6K. Anyone have any thoughts?

Thanks,
Brian

[squisher]

Re: 3.4 Lubrication Issues

10W40 maybe too heavy?

Not sure, it's not like it's significantly heavier than 5w30.

I wonder where all the metal from your cam lobes from the Crane 260. If those shavings were floating around in the oil a bit before they got filtered (if they were even big enough to get filtered) then they could have spent some time munching on bearings.

I've also heard that they've occasionally got hardening issues on top of not being as much ZDDP in newer oils, so that might be why the Crane failed as well. (This last statement is subject to my memory being correct -- which it may not be)

[camaroman1181]

Re: 3.4 Lubrication Issues

10W40 maybe too heavy?

Not sure, it's not like it's significantly heavier than 5w30.

I wonder where all the metal from your cam lobes from the Crane 260. If those shavings were floating around in the oil a bit before they got filtered (if they were even big enough to get filtered) then they could have spent some time munching on bearings.

I've also heard that they've occasionally got hardening issues on top of not being as much ZDDP in newer oils, so that might be why the Crane failed as well. (This last statement is subject to my memory being correct -- which it may not be)

I seem to agree... The full synthetic oil is not good to break an engine in with, though it should not have wiped out your motor so quickly. Lot of newer, performance based engines arrive from the factory with full synthetic.

The metal from the 1st cam could be an issue. It could have even blocked an oil passege, or gotten into your oil pump.

It is curious that your still have full oil pressure after wiping out all the crank journals. I was under the impression that that sort of thing would drastically reduce oil pressure.

are you running a high volume oil pump?

[4thgenowner]

Re: 3.4 Lubrication Issues

Im guessing some garbage is getting into oil passages or somewhere in the motor. It's true new oil dont have zinc or phosphorus required for flat tappet cam break in. Rotella T diesel oil is great oil to break in the cam with. I second the metal from the first cam would be causing havok.

[87SC/SS]

Re: 3.4 Lubrication Issues

After the cam smoked, we did a complete teardown and rebuild. We tore it down to the bare block, pulled all the galley plugs out and sent it to the machine shop where it was again honed, replaced cam bearings and completely cleaned. We did have the crank turned .010 because there was some damage to it due to the cam shavings the first time around. When we got it back we pressure washed the block and blew out all the oil passages, cleaned the crank up in a parts cleaning tank, cleaned out the oil passages in the journals, and we did use bearings to match the machine work on the crank.

The reason for this was that we didn't want to have issues with cam remnants floating around the block. I did use standard Penzoil 10w30 (non synthetic) to break in the cam when I had the Crane cam then, after 30 mins of 2500 rpm break in, changed the oil, ran for 500 miles and then changed to Mobile 1.

So... we know there weren't any metal shavings floating around the block, at least none from the prior cam destruction. I did hear about the hardening issues with Crane Cams which is why I changed to an Edelbrock cam, which by the way did exhibit more usable power and a nicer idle.

We didn't use the oil pressure valve that goes to the filter housing, but my understanding is that, that is only required for when the pressure builds to high, it bypasses the oil filter and just flows the oil so it doesn't starve the engine. The oil pressure never pegged out the guage even at WOT, but then again I never revved it passed 4800 rpm.

As for the 10W40 I'm running that in my 87 Camaro with a built SBC and its got more than 5000 hard run miles and exhibits no issues at all. Plus I live in FL where the tempurature doesn't get much lower than 75* on a regular basis so 10W40 should be fine.

My dad and I built this in his marine repair shop. They build engines (both 2 and 4 stroke) there on a regular basis and have no issues. I was told by the guy at the machine shop "those engines are crap and you should never try to rebuild one". Neither my dad or I agree with that statement, these engines have been used successfully for years and rebuilt and used in racing applications regularly. Anyways I'm worried about building this thing again because of the money I've already sunk into it. I want to do a 3400/3.4 hybrid build but I'd like it to last for more than 5000mi. If you guys want I can list the parts we used to build the motor, if you think it'll help.

Thanks again for the quick responses,
Brian

[camaroman1181]

Re: 3.4 Lubrication Issues

are you using a high volume oil pump? now, i'm not exactly sure how our 3.4 engines oil the block.. but.. I wonder if the use of a high volume oil pump would require soem restrictors in some of the oil passeges. could the HV pump be putting too much into the top of the engine, and not enough to the bottom end? I'm kind of goign out on a limb here, but im just trying to give some suggestions to your problem. It's pretty wicked whats goin on with your engine...

[87SC/SS]

Re: 3.4 Lubrication Issues

The oil pump is a factory replacement. It's dressed up on the rear main cap and the pump itself to allow for easier flow, but nothing else. We've been at a loss on this since May so don't feel bad if you're drawing a blank. The answer we got from the machine shop was... "Gee I dunno, like I said when you started this project, you should try to rebuild these engines. You should have just put a V8 in it." Not very helpful input. Other than building the thing again and just hoping it doesn't blow up, I don't know what else to check. We even checked the block, but when we installed the crank with the main caps it spun without a problem.

I think this time around I'm going to bring it all to a different machine shop. My dad has been using this guy for years (10 +) with no issues but, that kind of answer is not helpful and I would expect a machine shop that builds performance engines to be able to have some sort of constructive advice.

Well this time around its getting a set of Ross forged pistons, P&P 3400 heads and intake, a Megasquirt II, and possibly a GT25 Turbo (depends on how far Amex will let me go). If it blows up this time, its gonna blow up big!

Thanks for your assistance guys, I really appreciate you taking the time to answer my posts.

Brian

[speedyz]

Re: 3.4 Lubrication Issues

I'm into this thing for almost $6K.
Brian

Get a V8?

[bigbrian442]

Re: 3.4 Lubrication Issues

Flat tappet or Hydraulic cam?

It sounds like you need some type of oil restrictor.

V8 Oldsmobile's do the same thing with a high volume pump and stock oil pan. All the oil gets pumped to the top end and the pan goes dry. The oil doesn't get back to the pan as fast as it gets pumped out. A deep oil pan helps too.

If you don't use the by pass valve at the oil filter housing you still need to plug the hole or the oil will by pass the filter. The valve opens and by passes the filter when the filter gets clogged to keep your oil pressure up.

Edelbrock cams are from the Elgin catalog and are re-boxed. You may see small difference in the advertised duration numbers, but only a few degrees. The duration @.050 they list the same. They are also much cheaper from Elgin.



Brian

[87SC/SS]

Re: 3.4 Lubrication Issues

Thanks Brian,

I can't tell you how many guys I've spoken to. I had people go as far as to say that the machine shop used old media when they ground the crank and created microscopic grooves in the crank which caused it to fail. I was getting some seriously off the wall explanations for this. Your's is one of the only ones that really makes sense. If the oil is bypassing the filter because there is no valve/restrictor then not only is it sending dirty oil through the engine but its pumping all of the oil to the top of the block starving the crank. Especially since this is a cam priority lubrication system. I have to be honest, I'm not happy that it was my screw up, but I'm glad I won't make that mistake again. The cam is a hydraulic flat tappet, as opposed to a solid flat tappet or roller.

Trust me SpeedyZ, if I had known the number was going to be $6K I would have just bought Z28, but it started out at $2k and just kept costing me more and more over the last 2 years.

Thanks again to all, your feedback on this is much appreciated. Time to put another grand into this thing and hope it lives. If it goes this time I'm sending it to the junk yard and crushing it myself. I guess on the bright side of things I do have another crank lying around :-D.

Brian

[bigbrian442]

Re: 3.4 Lubrication Issues

If you can't find oil restrictors for that motor, Go with a bigger oil pan and a stock oil pump. If you make the pan deeper make sure you extend the pick up too. You can also polish the path the oil follows to return to the pan. The area above the lower valve cover rail, the return holes in the heads and the lifter valley where the oil return holes are.

Brian