Very noisy top end

General Chat About Engine Build

Moderator: phpBB2 - Administrators

minorv8
Knows His Stuff
Knows His Stuff
Posts: 571
Joined: Thu Nov 23, 2006 5:10 am

Very noisy top end

Post by minorv8 »

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 the cam and heads from the old engine. To my big surprise I have a horrible valve train rattle. I took the top end apart, checked everything for any contact but 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).

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

I ran the engine without a valve covers, still noisy. It´s not isolated rockers, it´s 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.

But, when I shut down the engine all valves close 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.

Also, with fuel cut off I can´t get the oil pressure up with a starter motor. This also was easy peasy with the old engine.

Any ideas ?



DaveEFI
Gold Member
Gold Member
Posts: 4603
Joined: Fri Feb 26, 2010 4:27 pm
Location: SW London, UK

Re: Very noisy top end

Post by DaveEFI »

I've never seen any hydraulic tappets that allow the valves to close so quickly after the engine stops.
Dave
London SW
Rover SD1 VDP EFI
MegaSquirt2 V3
EDIS8
Tech Edge 2Y

minorv8
Knows His Stuff
Knows His Stuff
Posts: 571
Joined: Thu Nov 23, 2006 5:10 am

Re: Very noisy top end

Post by minorv8 »

Me neither... but I took a video of it, I´ll upload it one I get it downsized.

And these are the exact same lifters that worked last December when I ripped the engine apart.

User avatar
ChrisJC
Top Dog
Top Dog
Posts: 5039
Joined: Mon Nov 20, 2006 1:13 pm
Location: Northants / Cambs
Contact:

Re: Very noisy top end

Post by ChrisJC »

Are you saying it's noisy because there is too much clearance between the rocker and the valves?

Chris.
--
Series IIA 4.6 V8
R/R P38 4.6 V8
R/R L405 4.4 SDV8

minorv8
Knows His Stuff
Knows His Stuff
Posts: 571
Joined: Thu Nov 23, 2006 5:10 am

Re: Very noisy top end

Post by minorv8 »

I don't why it is noisy. Preloads are within spec, 2 sets of lifters are behaving the same. It not isolated lifters, it is all of them. When I put the engine together I did not notice anything funny.

At the moment I suspect that there is something wrong with the top end oil pressure.

Here is a link to a video:

Hope it works.

stevieturbo
Forum Contributor
Forum Contributor
Posts: 3979
Joined: Sat Nov 18, 2006 6:22 pm
Location: Northern Ireland

Re: Very noisy top end

Post by stevieturbo »

The noise is extremely fast...so would suggest all lifters ?

What is that intake plenum made from ? I've a cheap chinese Holley one on my car now and it's thin aluminium. It makes the most horrific noise ! If I place my hand on it, it dampens it down.

Not sure, but did you also say the engine is not making oil pressure ? Or pressure is known good at the oil galleries in the engine ?
9.85 @ 144.75mph
202mph standing mile
http://www.youtube.com/watch?v=XgWRCDtiTQ0

minorv8
Knows His Stuff
Knows His Stuff
Posts: 571
Joined: Thu Nov 23, 2006 5:10 am

Re: Very noisy top end

Post by minorv8 »

Yes, all lifters indeed. Oil pressure is around 45 psi at idle. Mechanical gauge. I will do some more checking tonight when I get back home.

Plenum is a modified Rover item.

User avatar
ChrisJC
Top Dog
Top Dog
Posts: 5039
Joined: Mon Nov 20, 2006 1:13 pm
Location: Northants / Cambs
Contact:

Re: Very noisy top end

Post by ChrisJC »

It really does sound tappety.
I boldly suggest that the tappet preload isn't what you think it is, and they are loose and rattly.
Do you have any shims under the rocker pedestals? If you do, you could remove them and see if it makes any difference.

Chris.
--
Series IIA 4.6 V8
R/R P38 4.6 V8
R/R L405 4.4 SDV8

minorv8
Knows His Stuff
Knows His Stuff
Posts: 571
Joined: Thu Nov 23, 2006 5:10 am

Re: Very noisy top end

Post by minorv8 »

Not boldly at all, a fairly logical suggestion :D

But, unfortunately no help. I do have shims and have tried both with and without. No change.

Yesterday I changed oil and filter. I had 10W-40 for break-in (which obviously has been somewhat limited :( ) and put 20W-50 in. The only change is that now the lifters do not bleed that fast down. I also checked with a mirror that front oil gallery plug is in situ in RH bank. Can´t see the LH side from distributor hole. I used a priming tool and got the engine primed rather quickly. I also noticed that there is a fair amount of oil oozing out of the cam/dizzy gear assy. There is a lubricating path along the cam keyway but that seemed like a lot.

Sorry guys, clutching at straws now... Anyway, looks like it´s top end removal festival in the very near future.

DaveEFI
Gold Member
Gold Member
Posts: 4603
Joined: Fri Feb 26, 2010 4:27 pm
Location: SW London, UK

Re: Very noisy top end

Post by DaveEFI »

If the tappets are bleeding down fast, I really can't see how it can be anything other than faulty tappets? Did you soak them in oil before fitting? I assume there is the usual signs of oil pressure at the rocker gear?
Dave
London SW
Rover SD1 VDP EFI
MegaSquirt2 V3
EDIS8
Tech Edge 2Y

minorv8
Knows His Stuff
Knows His Stuff
Posts: 571
Joined: Thu Nov 23, 2006 5:10 am

Re: Very noisy top end

Post by minorv8 »

How can a perfectly working set get faulty by themselves ? Remember, I had the same head, cam and lifters of the old engine and they worked perfectly in November. Block, pistons and rods are the only thing changed, everything else came from the old engine. And a new set of lifters be faulty straight out of box ? One or two I could understand but two sets, total of 32 pieces ?

No, I did not soak them. Cleaned them and fitted, then checked the preload, fitted shims because I had too much preload and only then primed the lifters. This is as per Crane Cams instructions.

Yes, plenty oil oil through the rocker post to rockers. I tested this also without the rocker gear fitted and lubricated my garage wall :-)

ratwing
Forum Contributor
Forum Contributor
Posts: 267
Joined: Wed Jun 13, 2012 7:40 am
Location: Medway

Re: Very noisy top end

Post by ratwing »

This is a clutching at straws suggestion but I wonder if the lifter bores have been machined a bit oversize?

DaveEFI
Gold Member
Gold Member
Posts: 4603
Joined: Fri Feb 26, 2010 4:27 pm
Location: SW London, UK

Re: Very noisy top end

Post by DaveEFI »

Clutching a straws too here. How long did you run the engine for? I've only once fitted new tappets without soaking in oil for a day or so, and it was very noisy for minutes.
Dave
London SW
Rover SD1 VDP EFI
MegaSquirt2 V3
EDIS8
Tech Edge 2Y

User avatar
JSF55
Forum Contributor
Forum Contributor
Posts: 991
Joined: Mon Dec 04, 2006 4:15 pm
Location: Swansea
Contact:

Re: Very noisy top end

Post by JSF55 »

Have the cam bearings been changed or renewed on this engine ?
So thats where it went !

minorv8
Knows His Stuff
Knows His Stuff
Posts: 571
Joined: Thu Nov 23, 2006 5:10 am

Re: Very noisy top end

Post by minorv8 »

This block has no signs of ever being run, std size, new cam bearings. The cam was actually a bit "tight" on bearings when fitted, needed some rotating to set in.

Based on serial number, it is a Morgan 3,9 block. It has P38 type main bearing caps that had been drilled/tapped for cross bolts. AFAIK these were not machined from the factory even if the block had the bosses outside and main caps for cross bolts. Whatever the reason, these had been machined for 7/16 UNC thread, not the smaller factory bolts (M10 ?). So, whoever has had his/hers hands on the block may have done something else. There´s got to be a reason why it was for sale cheap and unused. I did not find anything else wrong with it. Maybe I´ll finally figure it out :lol:

It has now ran maybe 15-20 minutes total.

But, next weekend I will drain the coolant, remove the intake manifold and check the lifter gallery whilst running the oil pump with priming tool.

Post Reply

Return to “Engines Area”