Engine and Transmission Tech

Jim, get some shut-eye, LOL. "These" motors tend to"open-up"more, than cast iron when , can I say, "warmish" ? Since oil throw-off increases to "square" of clearance increase, thats why I,asked about the oil pressure at clatter time-ok ? Jim, I'm glad ONE of us ,is rakin in the chips ? roverman.

I did install used push rods, but carefully inspected them for damage and found none. I have since replaced the first set with a different used set with no change.
I downloaded a Jasper Engines Technical Bulletin about rocker arm noise due to "hardened pushrod cups being insecure in the rocker arm". The car is now at a garage being evaluated by a race car engine builder. He is stumped, so far, but is leaning toward a broken or warped piece of the upper valve train. The "clacking"
or clattering noise is consistent with the timing of one component in the engine revolution, so it doesn't sound like crank, rod or wrist pin racket. There was some suspicious swarf in the oil pan, so I may have a bigger problem. The engine's PO claimed he purchased a short block rebuild that was "blueprinted". I don't have any
paperwork to confirm it, so... Pig in a Poke, huh?

Update: The "swarf" turned out to be some fuzz, a bit of dried silicone scraping and some aluminum bits I drilled out of the heads. Nothing of serious consequence. My mechanic ran the motor from cold and it exhibited the same behavior; sounds great cold but when the temp reaches 190F a clatter-clack-not-quite-a-knock becomes audible and alarmingly loud. Oil pressure does not go below 18-20 pounds at hot idle and goes up to as high as 60 pounds at hot revving. The valve lash at idle was .006" or less at each valve stem head when hot. Rod ends, rod bearings and crank surfaces at the rods all look new on dis-assembly.

It is as though someone flipped a switch at 190F and started the mysterious, troubling engine noise. When the car is driven the noise disappers on deceleration, and sometimes at idle, reappears at acceleration, but not through the entire power band. In overdrive at 60MPH it will come and go with no discernible rhythm.

The mechanic is keeping the car for a while and has invited a couple of other skilled wrenchers to offer opinions before pulling the engine and tearing it down.

The saga continues.

Ken, one more time, finger on rockers? Stethiscope ? While clacking, pull, 1 plug wire, at a time. Automatic with sheetmetal flex plate ? End-play on crank/cam, ie. enough for/aft movement to cause noise ? roverman.

Valve lash? with Rhoades lifters? Should be preload, there should be no lash clearance ever, these are hydraulics.

Alan

Ken, Does this motor have a"retainer plate" on cam ? Thrust button ? If cam is thrusting forward, 8 lifters will have"reduced "pre-load, and/or chain, sprocket/etc. may be hitting. Good Luck, roverman.

I took the car to a mechanic I know who had three other mechanics listen to it run. After a bunch of head scratchin' and a visit to a local cylinder head rebuilder, it was determined that there was a strong possibility that a valve seat was loosening when the cylinder head temp got to operating level. The head rebuilder had worked on numerous Rover heads with this problem. The steel seat would migrate when warm/hot and reseat when cool/cold. At any rate, the heads are in the shop. I should have word on Monday or Tuesday
June 21 or 22.

Here is the latest. The heads were disassembled, heated up and the seats and guides did not move when pressurized. I am not clear on the process, but I have no reason to doubt someone with a good deal of experience with head rebuilding when he says they are not the problem. Good news for the heads. Bad news is that the engine "clacking" noise may be coming from the block somewhere.The head rebuilder noticed that there were NO oil seals on top of the intake valves, so he is installing them.They will come back to me as "newly reconditioned".

A local Rover engine mechanic I know posits that it may be an elongated lifter bore as he has seen that on other Rover engines. That could account for the lifter being quiet when cold and then starting to rattle around in the bore when warm. Whatever it is, I have not gotten a solid diagnosis from 5 independent mechanics. At any rate, I am ready to chuck this power plant and go to plan B which is convert to a documented, warrantied, rebuilt Ford 302. At least then I can buy parts from just about any parts store in the US. The PO assured me this short block 3.5 Rover was blueprinted when it was rebuilt, but I now have serious doubts about it. Since I bought the project car two years ago, and he bought the short block in 2004, I just have to suck it up and move on. I will probably be parting out the engine, D&D bell housing, lightened flywheel, clutch assembly, etc., for sale on EBay.

Hey Ken,
Sounds like you've done the valve train thing to death. If this were in my shop I'd be having a real close look at your rods and pistons. A bent rod will make the noise that you are experiencing but should have shown up as a side load on the rod bearings. Or more probable is a wrist pin problem in the piston. Either the pin bore is worn or more likely damaged by a ham fisted installer. This will make the exact noise that you are hearing, quiet cold, loud on accel and quiet on decel. I go through this a lot on high boost turbo engines that detonate themselves right out the tailpipe. If you have the stock 3.5 pistons there is a good chance that a skirt is cracked or collapsed as well. Same noise different source.
Hope thats more helpfull than depressing.
Fred
PS if you part it out we need to talk. My 907 headed rover v8 is almost ready to go and the lotus trans isnt going to like it.

Fred, Thanks for the post. The heads are still off the engine and it is still at the shop. I will be talking with the mechanic today. We have discussed the two problems you relate to in your post concerning wrist pins and pistons as the possible source of the noise. He has been reluctant to do a complete tear down, though he has had the main and rod bearing caps off to look for signs of wear and found none. The pistons are stock and appear the same vintage as the block. It may come down to a complete tear down, soon. Ken.

Ken, could it be the liners as in the article two posts down?

The liners are where they should be.

Just been reading this thread with interest, I used to have a classic car restoration business and MG’s were our main stay, we normally had 10 to 15 in the shop at any one time, we also used to put lots and lots of the Rover V8 in these and other sports and specials.
I can think of any more reasons why you should get this supposedly rocker or lifter click. Anyway don’t worry too much about inlet valve stem seals, they go hard after a few 1000 miles anyway and it is common for them to break up and fall apart. Never used to fit them on exhaust.
I am not sure of the set up you have exactly form the descriptions but we used to have to spend a bit of time setting up the valve gear when any high lift cam, different rockers were fitted due to the machining tolerances being all over the place. The way we used to get a fairly reasonable pre load was with the use of shims under the rocker pedestals. With the lifters we used to squeeze the oil out of them, install the rockers and a set of shims, then to get an average 40 thou preload we would measure from the top face of the inner part of the lifer to the underside of the retaining circlip, using different size wire gauges. Hope that is clear, I’ll try drawing if you like.
We would always get a discrepancy and never always get them to 40 thou but all near enough to run. These engines are so simple to rebuild and set up, we could put them together in a few hours once the machining is done, so either you problem is a very simple one a very big one.
Also someone mentioned the oil booster plate, be very careful and make sure you grind or machine a relief slot/passage in the casting between the 2 chambers, without this you will get over 70 psi with a new tight set up and it is possible to split the oil filter, happened to us a few times. We used to do this set up when the additional oil was needed for turbo charging.

Oil leaks in the inlet valley pan are common, clean everything, make sure faces are clean and use a nice bead of RTV sealant if you can’t get the rubber seal to work.

Ken and clan, last call...Stethiscope, finger on rockers or ground each plug wire, while running. roverman.

Dave and Art,

Thanks for the input. Oil pressure does not exceed 55psi, cold start and hot rev. Every conceivable engine running diagnostic has been performed by at least 4 trained mechanics and yours truly. Plug wire are new and
work as designed. Spark plugs are new and all work. No exhaust leaks. No detonation. No missing.

An East Coast Rover Shop owner, who has a blog on his web site, specifically referred to the problem my engine is having, using very much the same descriptors and says the culprits in his cases were pistons. Either a cracked or collapsed piston skirt will cause the exact same phenomena I am experiencing. The pistons are coming out next Tuesday morning and they will be closely inspected and measured as well as the cylinder bores. Since everything else has been ruled out, I am hoping to bring this to a conclusion.

I have not given up on the idea of installing a Ford 302, though it would be more appropriate, politically, and
period wise to have the Rover running right and enjoying a thoroughly British hot rod.

I used to feel that way about it too, but I've come to appreciate an iron block SBB instead. Looks nearly the same though.

JB

The pistons and rods have been removed from the engine and there are no visible signs of anything that could be causing the noise.

However, everything has been sent to the local rebuilder to be measured.

The PO was mis-informed about the rebuild. It was not complete, nor was it a "blue print" job. All the cylinder walls had glazing and the pistons all had wear and scuffing on the upper and lower surfaces as well as carbon buildup along the un-visible piston surfaces. It appears that the "rebuild" was basically a refitting of rings, a very tight re-installation and re-use of the bearings, which showed a fair amount of wear to the copper layer. So, the PO got a "Pig in a Poke", as did I. I guess I should have taken the short block apart, but I trusted the word of the PO, who I have known to be up front and forthright.

All this is very disappointing, as you might imagine. So, once the rotating assembly is spec'd and the cylinders are checked for roundness, we will come up with a plan to either rebuild, look for another BOP or Rover, or move to Plan B: the SBF.

How 'bout a 300 SBB?

JB

Ken, no culprit to be found? Pistons,"correct" direction on rods(off-set)? No cam gear hitting timing cover? Crank thrust and rod side clearance ok? Pressure check block ? Don't give up. Now you can build it right. roverman.

Ken

Sorry to hear you couldn’t find anything, I am not sure if you have checked this or not but we once had a Jag XJ6 4.2 1978 in the shop that had a sound much the same as you describe. We had it to bits a few times and couldn’t find a thing. It wasn’t till the owner said he had just had a top end overhaul with new valve seats, guides etc we started to get an idea.

Took the head off, heated it in an oven to just above working temp and “clink” the valve guide dropped out.
It wasn’t untill the head was really hot and expanded it fell out. During normal running it was moving and the valve was clouting it. Wasn’t untill we pressed it out we could see the damage. We couldn’t shift it normally untill very hot. The old guide had been pressed out and over size valve guides fitted but the machine shop had cocked up the machining and to compensate for a loose fit had knurled the guide to make it fit tight.

Just a thought mate.

If I could afford it I would come over and have a look but visiting the LeMans classic last weekend cleared me out of funds.

Don’t give up.

David