Engine and Transmission Tech

tips, technology, tools and techniques related to vehicle driveline components

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minorv8
Jukka Harkola

(179 posts)

Registered:
04/08/2009 06:50AM

Main British Car:
Morris Minor Rover V8

Valvetrain issue with new engine
Posted by: minorv8
Date: June 10, 2019 05:32AM

i posted the same question to UK V8 forum but hoping for new ideas or insight.

I have bit of a dilemma with my new engine. I assembled a new short engine (3,9 block, TVR 500 rotating assembly, all new) and fitted basically everything else from the old engine (heads, cam, lifters, timing cover incl oil pump, etc). To my big surprise I have a horrible valve train rattle. I took the top end apart, checked everything for any contact but found no visible issues. Valve pockets are deep enough, there is 0,1" valve to piston clearance. The only issue I found that my Comp Cams pushrods from the old engine were a bit too short for proper preload so I fitted a std Rover set. I also replaced the lifters to new set (Crane anti-pump up). Cleaned them, fitted them dry, checked preload, needed to fit some shims and then primed the engine.

All fixed or so I thought. Fired the engine and it was still the same. Noisy as hell.

I ran the engine without a valve covers, still noisy. Itīs not isolated rockers, itīs all of them. On both banks. I even took out all lifters from left bank (with Merlin heads you can actually get them out with a pair of magnets and even get them back in situ) and they are rock solid. You need to put them in a vice to collapse them. I disassembled the used ones, no issues.

But, when I shut down the engine all valves closed within 15 to 20 seconds as if there is no pressure in the oil gallery at all. Idle oil pressure is around 45 psi (cold engine). Like I said, same lifters, cam, heads, same oil pump/timing gear cover as in previous engine. Known combination that has worked flawlessy. Only that on this particular short engine it does not work. I have let the engine warm up to a 210 degrees but it is the same, hot or cold.

I had 10W-40 oil for break in. When I primed the engine for the first time with a priming tool I noticed that it took a long long time to prime it. This was a bit odd since usually my engines have primed withing a relatively short time. I changed the oil yesterday to 20W-50 and it primed again pretty fast. Also, it helped with the lifter bleed down. But the top end still rattles.

The rocker gear gets oil just fine.

When priming the engine yesterday, I noticed that there is quite a lot of oil flowing from the vicinity of dizzy drive gear at camshaft. As it should since there is a oil feed thru the keyway. I do not know what is normal/typical amount of flow.

I simply do not believe that I suddenly have 16 faulty lifters that have worked perfectly AND 16 news out of the box that are also faulty.

That just about covers it. Logically, if I change only the short block and get issues the problem should be in the short block. I guess Iīll rip the top end apart next weekend. And if I still donīt find anything itīs time for engine out.


RDMG
Dave R
Northern Virginia
(123 posts)

Registered:
04/07/2016 08:29PM

Main British Car:
1979 MGB 4.6L Rover V8

Re: Valvetrain issue with new engine
Posted by: RDMG
Date: June 10, 2019 08:24AM

What’s the history of your block, and what machining work did you have done to it? If it’s seen a lot of miles and or been abused, there may be excessive wear around the lifters.


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5833 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: Valvetrain issue with new engine
Posted by: BlownMGB-V8
Date: June 10, 2019 09:16AM

Post the exact procedure you used to determine valve lifter preload. I think you may find that is the cause of your problem. These engines like as much as about .060-.080" preload. Never less than .040" and certainly not the .020" that some recommend except in a race only engine.

It's a balancing act between preload, valve spring pressure, and redline. The higher the redline the tighter the balance and therefore the greater likelihood of clatter. One example that illustrates: Spring seat pressure of 120#, .065" preload, redline about 5000rpm. This can be shifted up with heavier springs, less preload or both. Stock specs of around .040" and 100# gives a redline approaching 5400 with some chance of clatter. Pretty much in the sweet spot for manufacturing. For more spirited driving on a rebuilt engine, .050" and 150#+ could get you to 6K or better, depending on spring pressure, cam profile, and a number of unknown factors. Beyond 6500 things get a bit more dicey and solids are a reasonable recommendation, although I have seen 7K with hydraulics. But if a quiet idle is your priority stay above .040" on the preload, stay away from Rhodes lifters, make sure you have plenty of oil pressure (10psi/1000rpm), and use spring pressure to raise your redline.

Jim


minorv8
Jukka Harkola

(179 posts)

Registered:
04/08/2009 06:50AM

Main British Car:
Morris Minor Rover V8

Re: Valvetrain issue with new engine
Posted by: minorv8
Date: June 10, 2019 10:53AM

The block is new, crank, rods and pistons as well. No worn stuff at all. I bought a pile of parts close to 10 years ago and the block was in that pile. There may actually be a reason why it was for sale and cheap.

Preload: cylinder #1 at TDC. Fit pushrods and rockers. Torque to spec. Measure the gap between plunger and circlip. I had about 80 thou + preload, fitted 25 thou shims so the preload is around 50-55 thou. Check other cylinders following the firing order. I tried to run it without the shims as well. No change.

Yes, a quiet idle would be nice 😂


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5833 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: Valvetrain issue with new engine
Posted by: BlownMGB-V8
Date: June 10, 2019 03:11PM

I'm not sure that method is going to do the job, it doesn't quite sound right. But first, did you say that your lifters are leaking down? They should not. If they are doing that you'll never get it to work right. The valves that are open when you stop the engine should stay that way, at the very least for a couple days and really much longer than that. If they aren't you might want to start there.

We know that lifters can "pump up" and hold the valves open if the engine over-revs. This is a combination of valve float, and the lifter piston operating in an intermediate zone at something less than full extension, which really is what your preload determines. So when you set preload, you are also setting how much movement is allowed during pump-up, if it occurs. The more allowed, the longer it takes for the engine to settle down afterwards, and the higher the risk of piston contact. So yet another trade-off.

What this means is that full lifter extension is the baseline for the preload setting. I have used setup lifters with the pistons locked at full extension for this, adjustable pushrods set for zero valve lash, and then add the preload dimension to the length of the pushrod. I think this is the usual method.

Jim


quietone
Larry Mimbs
Tennille, Ga.
(93 posts)

Registered:
07/13/2013 04:22PM

Main British Car:


Re: Valvetrain issue with new engine
Posted by: quietone
Date: June 10, 2019 03:14PM

My guess is that you are hemorrhaging oil with an oil gallery plug missing or some mismatch of parts.


minorv8
Jukka Harkola

(179 posts)

Registered:
04/08/2009 06:50AM

Main British Car:
Morris Minor Rover V8

Re: Valvetrain issue with new engine
Posted by: minorv8
Date: June 11, 2019 01:22AM

Yes, with 10W-40 oil they leaked down in 15-20 seconds. I took a video of it, Iīll upload it once I have the size reduced to something reasonable. With 20W-50 it was much slower. Yes they are not supposed to and the exact same lifter/head/spring combo did not do that with the old short motor. It took days. So yes, I do believe that the oil leaks somewhere it is not supposed to and there is not enough oil pressure in the oil galleries to begin with, not matter what the preload is.

Jim, with Rover valve train there is no adjustment, only the shims underneath the rocker pillars. Pushrods are one length only, giving enough preload with factory blueprinted dimensions (if such even exist with british products). With various combinations that I have built there has been cases with shims, no shims or even pillar that had to be machined lower. But the method I described is the one I have used for 20 years, yes it is tedious, almost impossible to do accurately if you have engine assemble with manifold in situ.

I have also used lash caps on some engine, both to correct geometry if needed and save the valve tips from mushrooming. Note again the UK products nowadays are not exactly best quality available. I have had case where valve removal required so valve tip dressing with a file.

Oil gallery plugs are one thing that I suspect, especially at front. The gallery for even number cylinders is plugged, that I could see with a mirror. Odd number cylinder plug cannot be seen. The rear of the galleries canīt leak, otherwise I would have a pool of oil underheath the bellhousing.

Next step is to drain the coolant, remove the Efi manifold and to check what happens at lifters while running the oil pump with a priming tool. At least I know what I will do next weekend...

Irony is that I was supposed to run this engine only this summer. I have another block on engine stand and there are after market Wildcat heads waiting for that block. I just hit a little speed bump with that project and need to sort that somehow.



minorv8
Jukka Harkola

(179 posts)

Registered:
04/08/2009 06:50AM

Main British Car:
Morris Minor Rover V8

Re: Valvetrain issue with new engine
Posted by: minorv8
Date: June 11, 2019 09:36AM

Here is a link showing the rocker bleed down with 10W-30 oil. Best seen on cylinder #3.

[drive.google.com]


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5833 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: Valvetrain issue with new engine
Posted by: BlownMGB-V8
Date: June 11, 2019 10:31AM

Well Jukka, it does look like you have two bad sets of lifters. No way they should be bleeding off like that. Nothing else could cause it if there is oil in the lifters to start with. Of course you could open them up and reassemble submerged in oil to make sure but you probably wouldn't be able to get the circlips back in. You shouldn't be able to get them to leak down even a little. That's why Rhodes lifters are so noisy. They leak down.

What we do Stateside is we order custom pushrods from Smith Bros. in the length and configuration we need. Usually they have them in stock and can ship the same day. Costs about $100US/set. maybe a smidge more. I'm sure they ship overseas. Good, quality parts.

They will also sell you a pair of adjustables if you want, but I made them from old pushrods and some screw ends cannibalized from somewhere else. To make the setup lifters I removed the piston, dropped in a screw and nut, and adjusted it so the circlip would just clip in over the pushrod seat.

HTH,
Jim


minorv8
Jukka Harkola

(179 posts)

Registered:
04/08/2009 06:50AM

Main British Car:
Morris Minor Rover V8

Re: Valvetrain issue with new engine
Posted by: minorv8
Date: June 11, 2019 02:19PM

Jim, could you explain to me why this set of lifters did not bleed down in the previous block but does that in the current one ? What makes them bad if they sit on a shelf for 5 months ? And if I take one of these lifters out of the engine I need a vice to push the plunger in. I took 8 of them apart, using my bench vise and yes they were oil in them.


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5833 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: Valvetrain issue with new engine
Posted by: BlownMGB-V8
Date: June 11, 2019 03:31PM

Could be dirt in them Jukka, that's about all I can come up with unless they have air in them. The bore and piston are very precisely honed and matched. If you switched any parts that could be an issue. Look, when there is oil in the lifter and no air, it should act just like it is solid. Oil shouldn't be coming out and it should not be compressible without applying hundreds of pounds of pressure and holding it for an extended period. If you can compress them in a vise that tells me something is wrong.

Any chance these are anti-pump-up lifters?

Jim


minorv8
Jukka Harkola

(179 posts)

Registered:
04/08/2009 06:50AM

Main British Car:
Morris Minor Rover V8

Re: Valvetrain issue with new engine
Posted by: minorv8
Date: June 12, 2019 01:18AM

Crane 99284-16


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5833 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: Valvetrain issue with new engine
Posted by: BlownMGB-V8
Date: June 12, 2019 08:44AM

Maybe contact Crane and speak to their Technical department?

Jim


minorv8
Jukka Harkola

(179 posts)

Registered:
04/08/2009 06:50AM

Main British Car:
Morris Minor Rover V8

Re: Valvetrain issue with new engine
Posted by: minorv8
Date: June 12, 2019 11:45PM

I bought a set of Comp Cams lifters, I will let you know how they work.


minorv8
Jukka Harkola

(179 posts)

Registered:
04/08/2009 06:50AM

Main British Car:
Morris Minor Rover V8

Re: Valvetrain issue with new engine
Posted by: minorv8
Date: June 14, 2019 03:19PM

Changed the Crane lifters to a new set of Comp Cams lifters. Primed the lifters without the rest of the valve train. Nice even oil flow thru each lifter. Assembled the valve train. Still rattling...



Special
ED TESTA

(7 posts)

Registered:
04/24/2019 09:58PM

Main British Car:


Re: Valvetrain issue with new engine
Posted by: Special
Date: June 15, 2019 12:36AM

Just a thought but we had a set of pushrods that were hitting the side of the guide hole through the head on an engine we had at the dealership, this was after a repair (if i remember it was a valve job). Another thing we saw regularly is the tin cup that is swedged in the rocker cup would come loose and sounds like a lifter rattle. Did you rebuild the rockers while they were off?


minorv8
Jukka Harkola

(179 posts)

Registered:
04/08/2009 06:50AM

Main British Car:
Morris Minor Rover V8

Re: Valvetrain issue with new engine
Posted by: minorv8
Date: June 18, 2019 12:24AM

No rebuild, the same rockers were fitted to the engine last December and did not make any noice. The cups are intact. I had do grind the guide holes when I fitted the Comp Camps pushrods years ago. I now have std rover pushrods that are slightly thinner. So no chance of hitting.


roverman
Art Gertz
Winchester, CA.
(3006 posts)

Registered:
04/24/2009 11:02AM

Main British Car:
74' Jensen Healy, 79 Huff. GT 1, 74 MGB Lotus 907,2L

Re: Valvetrain issue with new engine
Posted by: roverman
Date: June 27, 2019 06:36PM

Got stethoscope/ hose to hear/isolate noise ?


minorv8
Jukka Harkola

(179 posts)

Registered:
04/08/2009 06:50AM

Main British Car:
Morris Minor Rover V8

Re: Valvetrain issue with new engine
Posted by: minorv8
Date: June 30, 2019 01:46PM

Art, I would say that it is useless...

Here is a video link: [drive.google.com]

I removed the intake today and primed to engine with a priming tool. With rocker gear in situ I get oil to rockers but not to the lifters. Then I removed the RH side rockers and blocked the oil feed. I then got oil thru the RH lifters and once primed they stay rock hard like they should. However, no oil to the LH lifters. Whichever lifter is compressed stays compressed.

So, next step is to rip the front of car apart and remove the timing gear cover. There obviously is an issue with the oil feed.


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5833 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: Valvetrain issue with new engine
Posted by: BlownMGB-V8
Date: June 30, 2019 05:46PM

Ah. Possibly the wrong plugs in the end of the oil galleys, or screwed in too far.

Jim
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