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| Northstar rebuild: Will style (Page 32/119) |
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befarrer
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JAN 12, 11:30 PM
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| quote | Originally posted by Will:
This is what the lifters look like:
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This one has what appears to be a circumferencial crack about 1/8" down from the top of the lifter. Allen Cline assured me that this is also normal. It is the part line between the wear surface of the lifter and the lifter body. The wear surface is friction welded to the body.
This is the bottom of the lifter:
.jpg)
You can see the hole which allows oil inside the lifter. The factory valve lift is greater than the width of the galeries which supply oil to the lifters, so they don't need continuous oil pressure in order to function. Allen Cline said that when they were introduced, they were state of the art.
Oops... I haven't taken a picture of the tool yet... I'll get to that tomorrow.
I almost made a bad mistake... I timed the right bank, then bottoned it up. I replaced the seals and springs on the left bank, then timed it and buttoned it up. I opened the right bank back up to double check something and noticed that the timing marks were way off...
Because the N* has an intermediate timing drive with strange ratios, there are funky things that go on with timing. The crank to intermediate shaft ratio is 7:5 (7 turns of crank to 5 turns of intermediate sprocket). So when you turn the engine a bit (as we did to bring each cylinder in turn to TDC), you'll have to continue to turn it until you've turned it a total of seven times in order to get the timing marks on crank and I-sprocket to line back up. I did this in between timing the right bank and timing the left bank. Anyone know what this means? Turning the crank 7 times turns the cams 3.5 times... so the right bank and left bank would have been 180 degrees out from each other. Good thing I caught that...
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I know this is like over 2 years old, but the Quad 4 lifters look EXACTLY like these, I dont have any good pics, if I remember I will try to get some tomorrow, but here are what I have:
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84 Fiero Sport Coupe #1192 :: 86 Fiero Base Coupe Quad 4 HO :: 1995 Dodge Ram 1500 2WD Club Cab Long Box 5.2L Auto
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Will
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JAN 13, 08:39 AM
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I had been curious about that. Do you know the Q4 lifter bore and the distance from the tip of the valve to the base circle of the cam?
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AJxtcman
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JAN 13, 10:41 AM
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Hello Will
I Have been at the Caddy dealer for the last 3 years. I had always though that caddy's were a little junkie. The door panels pulled, loose the motors leaked oil, trans leaked, Intake manifolds leaked, The oil filter was on the top, they had a throttle body and when they changed to MPI they still used the same style center mount T-body. Over the past 3 years I have learned that is all in the past. It ended in the early 90's.
From 96 to 99 common engine issues are the following.
The lower half leaks oil at the case halves and oil pan -- fix-- Do Not Use Gaskets--- New TriBond Sealer. Rear main seal leaks.
New seal has Metal sleeve that is pressed on to the crank with a special tool.
The ring are a low tension ring that allows the oil to get on to the top of the piston and this causes carbon build up--- Perfect Circle designed a second ring to help control this issue.
The Head bolts pull the treads out of the block-- time serts only work some times in these blocks --- the threads need to be cleaned and inspected completely-- inspect for pitting after cleaning out the thread locker--- if any pitting is found in the thread area it usually means that the block will not hold a time sert--- when drilling out the block if the material is grey and or powdery the factory time sert will not hold-- Either the thread locker has broke down the blocks or the aluminum quality was not that good---- old thread locker will bind up the threads and break then out--- I would say 50% of the blocks can not use TIMESERT time serts. GM has short blocks available for this problem or use NS300L inserts
The cams go flat--- if any circle markings are found on the lifters the cam is bad-- the circles range from 1/16 inch to about 9/16 is typical-- another sign of the cam wear is in the cam/valve covers-- it looks like casting sand and is built up on the lower sides-- when the valve covers were new the were smooth on the inside-- you can find this in the chain area of the cam cover also-- it does not wash off, but it will flake off sometimes.
The only way to fix the last two issues "block and heads" is to go with a 2000+ setup
2000+
Oil leak like previous years-- FWD RTV Sealant Procedure with Current Oil Distribution Plate TSB #03-06-01-027 - (10/06/2003)
rear main seal update Engine Oil Leak at Crankshaft Rear Main Oil Seal (Install Revised Crankshaft Rear Main Oil Seal Using Revised Rear Main Seal Installer) #05-06-01-019D - (05/12/2006)
The ring issues-- the new rings work better, but the also redesigned the pistons ---Engine Cold/Knock/Tick Noise (Replace Pistons) #03-06-01-025 - (09/02/2003
misc engine info----Information on Northstar Engine Mechanical Repairs #04-06-01-032 - (10/27/2004)
I have replaced the pistons in well over 100 engines for 2000+ and have only install 3 time serts --- I have never seen any pitting in the threads and when I drilled out the aluminum it was bright and shiny. I have never seen a bottom end fail with the exception of ingesting water "flood" or from this TSB Higher Than Expected Oil Consumption (Clean Piston Rings) #02-06-01-009C and we had a maintenance package that we performed a carbon treatment. We stopped doing it because the younger guys bent rods.
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AJxtcman
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JAN 14, 11:20 AM
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I was thinking about the 2000+ engines and I can not remember one haed gasket that has blown. This may be because the head bolts don't pull out of the block.
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befarrer
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JAN 14, 01:05 PM
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Will
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JAN 14, 03:16 PM
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The Northstar lifters measure 1.297" diameter, which is 32.94mm-- nominal 33mm lifter bore. They're 2mm smaller than Q4 units.[This message has been edited by Will (edited 01-14-2007).]
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befarrer
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JAN 14, 08:45 PM
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Hmm, but they look identical though, must have stole the design for the N*.
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Will
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JAN 14, 09:02 PM
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May have. GM's current roller follower overhead cam valvegear is common among the Northstar, Vortec 4200, Ecotec and High Feature V6. It's not a stretch to think that the previous generation of flat tappet OHC valvegear was common across several engines. I think the 3.4 TDC/DOHC started out at 35mm and went to 33mm later.
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AJxtcman
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JAN 25, 08:23 PM
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| quote | Originally posted by AJxtcman:
The cams go flat--- if any circle markings are found on the lifters the cam is bad-- the circles range from 1/16 inch to about 9/16 is typical-- another sign of the cam wear is in the cam/valve covers-- it looks like casting sand and is built up on the lower sides-- when the valve covers were new the were smooth on the inside-- you can find this in the chain area of the cam cover also-- it does not wash off, but it will flake off sometimes.
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Will I hope your project is going along. I have some new lifter pictures of the common failure. 90% of the time it is the EXH side.
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ryan.hess
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JAN 28, 06:23 PM
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| quote | Originally posted by AJxtcman:
Will I hope your project is going along. I have some new lifter pictures of the common failure. 90% of the time it is the EXH side.
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I wonder if that's what happens when you use Mobil 1.....
They were obviously designed to rotate to create even wear across the lobe and lifter surface, but there shouldn't even BE any wear if the oil is doing it's job. Obviously something with the ILSAC starburst like Mobil 1 might not provide sufficient ZDDP to prevent excessive wear. People using CHRF's springs should choose oil carefully.
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