I'm not sure what to make of this yet, but I decided to check the cam timing as it was originally set up by me - but using a different method since I had so much trouble with the initial attempt at degreeing the cams with the hydraulic lash adjusters. I had made a solid lifter and tried to set it for zero lash on the base circle of the cam.

This time I wanted to use the standard lash adjusters and let them do whatever they wanted to do - but take readings at several valve lift points to see if I could get a good average on the installed C/Ls of the cams. My initial goal on the cams was to install them straight up per Diamante spec to be at 115? C/L.

Instead of using the wobbly magnetic base as before, I cut a nylon sleeve lengthwise, inserted it in one of the indicator clamps and fashioned a much more stable mounting method on one of the head/intake studs:



Here's what I got for C/L on readings every .050" today:

Driver Side Cam

.050" = 116.5? C/L
.100" = 116.5?
.150" = 116.0?
.200" = 116.0?
.250" = 116.0?
.300" = 116.5?
.350" = 116.5?

So I'll call that cam 116.0? and pretty close to what my target was on the original installation.

- BUT - here's the surprise:

Passenger Side Cam

.050" = 110.0? C/L
.100" = 109.75?
.150" = 110.0?
.200" = 109.5?
.250" = 109.75?
.300" = 110.0?

I'll call that one 110.0? C/L and 6? off from the other side!!

What happened? I remember I originally determined the passenger side to be off by ~4 or 5? and advanced it about 5?, but that's opposite of what I'm now seeing as a difference - don't understand it unless 1 of 3 things have affected it:

1) The water pump may not be installed the same - I didn't bother to push it down all the way this time. [EDIT - nope, that would advance it more - EDIT]

2) I have an unused (never installed) lifter in the #1 cam follower and a used one in the #2 cam follower.

3) The magnetic base was not stable enough on the original setup and caused a 5? error on the passenger side reading.

Tomorrow, I think I'll swap lifters side-to-side and see if I get the same readings. If so, I need to advance the driver side about 8? (might not be possible) and the passenger side about 2? to get to the OE intake valve closing point..... I want to try them at 108? C/L this time.

Wow - what a surprise. <img src="/forums/images/graemlins/confused.gif" alt="" /> Hopefully tomorrow will shed some light on it.

Frank

Seems like alot of advance side-to-side, to me. Do you really think old/new lifters could cause that much disparity? I'd be more inclined to belive it's a measuring discrepancy. My $.02...

No, the lifters don't cause that much difference, because once the engine is running, the lifters pump up to zero lash - but there is a geometry difference between a collapsed lifter and one that has no lash..... and that does cause a bad reading. What I was trying to do was see if I could use the collapsed lifters without shimming to zero lash to check the original cam C/L installation. One lifter needed shimming and the other did not. I was surprised to find the 5? difference in cam C/L installation.

So, I spent all day yesterday checking on the checking. First I swapped the 2 lifters and found the same cam C/L readings, so the problem wasn't with the lifters. Next, I considered that one follower could be bent. So, I swapped in all 6 followers on that cam and found them all within .5?. I didn't check the 6 from the other head because I assume the machinist disassembled one head at a time - and/or kept parts together. I'll call him today to find out. [EDIT - a call to him verified he did work on one head at a time - EDIT]

I haven't tried to move the water pump down since it's already final installed with a new gasket - but I don't think it could throw that one cam off by that much and in the advanced direction.

I think it has to be a misread on the original installation - not terribly surprising given the difficulty of setting these cam C/Ls with the hydraulic lash adjusters and the way I tried to install them using a fabricated solid lifter and the OE spring rather than checking springs. When I examined the fabricated "solid" lifter that I originally used, I found that it had slightly collapsed from the pressure of the OE spring.... that's likely where the error was made.

I'm surprised that with a 5? cam C/L difference the extra power on one side didn't make the truck run in circles or flip over. <img src="/forums/images/graemlins/lol.gif" alt="" />

I now have one cam where I want it, but couldn't find a combination of sprocket tooth engagement and cam bushing that would set the passenger side where I want it, so I've ordered another set of bushings from Summit. I'll make one more attempt to set these up like I want them before I go back to the original truck cams.

I don't know which I like least - cam bushings or followers with hydraulic lifters. <img src="/forums/images/graemlins/baby.gif" alt="" />

Frank

Frank

Alt 0176 will give the nice deg symbol:

eg
116?

<img src="/forums/images/graemlins/wink.gif" alt="" />

?Thanks?

Now if I can just remember that.

Frank

Just in case anyone else wants to try this, I'll outline the procedure, but you're on your own. <img src="/forums/images/graemlins/barf.gif" alt="" />

You can find plenty of information on "How to degree a cam", so this will address only where a 3.0L diverges from standard procedure.

You need Chevy offset cam bushings - Summit sells them. Mr. Gasket sets can be bought in 0/2/4/6/8 and 0/1/3/5/7 degree packages - you might need the same bushing for each side, so it's best to get 2 sets of each - this is one set plus a few leftovers from before:


The cam sprockets must be drilled to accept the bushings - the drill size is noted in the instruction sheet that comes with the bushings. You also have to remove the dowel pin in the cams and drill the dowel pin hole to the correct pin size of the bushing, then either find - or machine a proper size dowel pin to fit - again, the size is listed in the instructions. It's also necessary to grind the pin so it sits just below the surface of the installed sprocket so the bolt can seat against the sprocket. The finished installation looks like this - note that in this installation, an offset bushing is installed to roll the cam forward to an advanced position relative to a zero offset:


I have tried to make a solid lifter for lash removal, but it's a waste of time and caused an error in the original cam setup when it collapsed slightly - so here's the best way I can find to do this with followers and hydraulic lash adjusters - use collapsed lifters, set the cam on the base circle and remove lash with a combination of feeler gauges of increasing total thickness until the limit is reached where there is no indicator movement. It's actually necessary to go .001" thicker than the dial indicator shows for "zero lash" and then readjust the indicator to zero - otherwise, the opening and closing points of the valve are way out of spec. You won't be able to use the opening and closing points given in the FSM, but can only read degrees on the wheel at various points before and after maximum lift. I used lift of .050/.100/.150/.200/.250, read the degree indications on both sides of the intake lobe and set the cams by the C/L method. Here's a picture of the feeler gauges, but I just stuck them in for the picture - they really should be inserted a little further - to completely cover the valve stem, but not so far that they override the rear side of the spring retainer:


Here's the final adjustment finished - both cams within a whisker of 108? C/L - 7? advanced from the OE Diamante spec, but now closing the intake valve at the same 59?ABDC point as the Montero, which will increase cylinder pressure and raise my DCR to ~7.5:1


Additional trivia:

1) This time I used Summit's checking springs - installed on #1 & #2 intake valves.... you could probably use a couple of the rocker rail springs - they look pretty close to the same thing.

2) I removed all rocker arms and springs (except #1 & #2 intake) from the rocker assembly so I wouldn't have to remove the remaining valves.

3) I installed the heads with an old set of head gaskets, so I could remove the heads after the cams were dialed in... for ease in reinstalling the valve springs that were removed to use the checking springs - and for a final cleaning and assembly with new gaskets and seals.

4) I found it helpful to swap sprockets side-to-side to adjust slight differences in cam readings - particularly since the bushings only give a 2? minimum difference at the crankshaft.

This is the toughest job I've tried on a 3.0L - and I still can't figure out how to get an accurate reading on cam duration - the hydraulic lash adjusters just ain't made to do even what I just did.

I "think" it's what I want now. I'm trying to move the beginning of the torque band down from 3100 rpms to hopefully ~2500 rpms plus realize a power gain. I may not get it down as low as I'd like since I'm fighting additional cam duration, additional valve overlap, a larger exhaust and shorter intake runners - all of which favor the upper rpm area. The dyno will be the judge. <img src="/forums/images/graemlins/kewl.gif" alt="" />

Frank

I see this thread has been "stuck" - thanks, fellows - I feel flattered, but as of now.... undeserving.

The engine's in, but not right at all. It fired off and ran fine for the initial 20 minute high idle run-in. Oil pressure was about 50 psi on the mechanical gauge..... lifters quieted down to nothing after a few minutes. No leaks.

Changed the oil and filter and went for a drive to seat the rings without realizing I hadn't installed the S/C bypass valve vacuum hose. Started with acceleration/coast runs..... 0-2500, 0-3000, 0-3500, 0-4000, 0-4500...... everything seemed normal, so continued to drive.

On start-up, I had tried to revert to an earlier .msq file to avoid the high VE table values that were set by AutoTune just prior to blower failure.... couldn't get the .msq to change, so used the latest file. I switched on AutoTune to see if it would reset the correct VE table values on the drive.

Everything seemed ok on the drive and after about 15 miles I punched the throttle - no response - engine started to slow down - wouldn't rev - looked at temp... it was ok - looked at oil pressure.... it had dropped to zero on the factory gauge. Stopped, checked the oil - about .5 qt over, the engine was hot but didn't show on the coolant temperature gauge..... would not restart.

After an hour of letting it cool and looking at it, I noticed the missing blower vacuum hose and a weird looking coil wire connection. The wires were new - coil wire distributor connection had not fully seated, and had burned the corner off the tower insulator from arcing..... fixed that temporarily. After cooling, the engine would start, one loud lifter tap, but wouldn't stay running.... so I left it and towed it home yesterday morning.

I reverted to the old dyno-tuned .msq and tried a restart - got oil pressure, but lost it again as the engine warmed.

I've drained the oil again and will take it for analysis - it looks funny - maybe from all the assembly lube I packed in the pump. It may have some gas in it from the bad VE tables and lack of air from the blower not having the bypass vacuum hose attached.

I pulled one plug - very black - checked compression on that cylinder - 165 psi. The heavy black deposits could be from weak ignition caused by the coil wire arcing.

Oil pressure possibilities:

1) The oil pump relief valve stuck open
2) Bad oil filter
3) A/F mixture too rich, gas in sump, high oil level, thin oil, crankshaft whipped up froth, oil pump lost prime.
4) The rear main bearing clearance is too tight.

When I installed the main studs, I didn't use a bore gauge and didn't align hone the bores. The rear bore was tight at .001" as measured by Plastigage, but turned ok by hand with 30W lubrication. I'm wondering if the clearance was too little with heat and if that could cause an oil pressure drop...... I would think the bearing would spin and I'd hear it - but I don't.

First things first - I'll replace the distributor cap, change the oil and filter again and see what happens.

Frank

Hi Frank, Read your line again. Can't happen.
More than likely it would be a stuck relief valve.

That's my thought as well, but it would seem that a spun bearing would cause higher pressure.

I did clean the relief valve when I had the oil pump apart. I don't see how the valve could be fine on initial startup, but then stick open - unless the thinning viscosity as heat builds causes the drop.

I'm wondering about all the assembly lube I packed in the pump - and if that could cause the valve to stick.

Short of removing the oil pan and replacing the pump or valve, I don't know what I can do about it. Maybe an oil change will help.

I've never seen this before. <img src="/forums/images/graemlins/rolleyes.gif" alt="" />

Frank

Replaced the distributor cap.... Note to Belden ignition wire users: Be very careful with the seating of the terminals.... I found 2 that were not inserted straight into the socket. I did have a friend who was helping install the wires, but I did see that the terminals have a tendency to angle away from center inside the boot. The engine now starts fine.

I replaced the plugs with new ones and checked compression - all cylinder pressures are fine.

I also changed the oil and filter..... same results on pressure. Oil pressure is fine on startup, but begins to drop as the engine temperature increases. The oil becomes very hot and doesn't get to the top end. I don't know what else to do except replace the complete oil pump assembly..... I'd hate to take it apart to clean/replace the valve and find it still bad on reassembly.

Frank