Compression=0...what would you do?

[Moat Creek]

Hello:

I have a 1960 series 2-88 rover that I have been working on for some time that I bought from a fellow here in S. Cal that had not used the vehicle for many years. A year or so back I got the rover running with the intent of checking out he mechanical systems before tearing the whole thing down when I had money to replace frame/bulk head. Before I started the tear down I was having issues with the carb. One fine afternoon I replaced my BV carb with a rebuilt one. I took the rover out for a spin and it ran really, really well for five blocks & the the starter gear locked onto the flywheel (very loud sound down by my feet) & rover coasted to a halt.

When the starter gear/spring failed I decided it was a sign that the tear down should start since I would need to inspect flywheel. My plan was to have a local series rover engine expert (Pat) rebuild the engine while the rebuild was going on. As it turns out he was busy with projects so I decided to re-install the engine since it was running well & I could pull it later (less then a six pack of beer job) if there was an issue or if engine rebuilder schedule cleared.

To make a long story shorter I got my rover friend reassembled & fired up the engine. After working through a few vacuum leaks I have a steady idle but I believe at this point I have a stuck/bent valve (caused by sitting/gum?). The ignition system is working well & I set timing by Green bible & verified with timing gun (mark is rock steady). Engine idles nice but is loud & lacks power. I am positive when I replaced carb I did not drop anything in intake manifold & complete engine sat in a corner of my garage while I rebuilt frame, etc. Compression in #4 cylinder is zero and it is a 8:1 head. See below info gather after engine was warmed up with a decent screw in type compression meter....new starter was used to crank:

# PSI PSI after oil squirted in cyclinder
1 115 125
2 135 140
3 140 150
4 0 0

It seems like I could get a rebuilt head and install it but I am not sure if based upon compression readings & age of other components it may make sense to either get a rebuilt engine or try to find someone to rebuild. It has new fuel & water pump but timing chain/tensioner/distributer were not replaced. I do not have the knowledge or time to learn to rebuild engine (house is for sale). So the way I see it my optons are:
1) I can replace head & see what happens (if does not solve issue then I may have wasted money & time).
2) Get a rebuilt engine (solves problem but costs $)
3) Try to find someone to do engine rebuild (any names in LA area would be appreciated) not sure of what the cost would be on this option..any thoughts? Engine may not be original and must ahve been rebuilt before...how many times=unknown.
My goal is to drive drive rover to next house vs a sad trip on a flatbed :( . I plan on keeping my rover friend very long term & use for running to Home Depot, fishing, camping,,,,

Sorry for long post but I appreciate your feed back!!

Eric

[LaneRover]

When you run the engine - or just turn it by hand with the valve cover off can you see the valves for #4 moving?

[willincalgary]

When you run the engine - or just turn it by hand with the valve cover off can you see the valves for #4 moving?

I would strongly suspect a stuck valve. Check that first before you spend anything.

[ignotus]

Sounds like it could have been the connecting rod or something else in the motor.
do as been suggested^^^ pull the valve cover and turn the motor with the crank handle and see if the valves move. If they do pull the plug from #4 and put a piece of wire in it and see if the piston moves up and down using the hand crank.
Any metal in the oil pan?

good hunting!

[SafeAirOne]

Eric,

I'd avoid replacing item after item till it's fixed. It may be a simple $200 (including parts) head job. It might be a whole new block. I'd suggest that you troubleshoot and identify the exact problem as described in a few of the other posts. That way you'll know if you're in for a simple, fast and cheap fix or whether the engine is toast.



Just trying to run through scenarios where compression would equal zero on one cylinder...

Valve stuck wide open

Piston not moving at all

Large hole in cylinder wall/block

Large hole in piston


I can't think of any more off the top of my head. I'd think that without any rings installed you'd still get some sort of reading on the compression tester.

[73series88]

yep gotta get that head off.
keep us updated
aaron

[Les Parker]

Could be a displaced push rod or valve tappet.
Remove the valve cover and have a look see.

:confused:

[mongoswede]

Put a small squirt of oil into the cylinder and check the compression again. If the compression comes back its a sign that the rings are bad or not sealing. If there is no change then suspect valve train.

[fubog]

I would remove the rocker cover and inspect the valve operation, as has been suggested, and (pending the results of the visual) set the bad cylinder at TDC compression and air it up. This is just a crude form of a leakdown test.
HTH
Glen in Fla.

[SafeAirOne]

Put a small squirt of oil into the cylinder and check the compression again.

He did in the OP. That's the second number in his compression readings.

[mongoswede]

He did in the OP. That's the second number in his compression readings.

who reads the original post :sly::D

[Moat Creek]

Thanks all for your input an comments. I did a liitle work tonight and following are results.

1) I borrowed a fiber-optic borescope from work and checked cyclinder #4 which had the zero compression. From what I could see (2/3 of top) the piston has no holes and seems to move up and down freely when cycling starter. With the borescope I could also see both valves open in sequence with no sticking apparent. The valve heads look normal from the side view. I also looked at all the cyclinders and they seem consistent with #4. Piston crowns have some areas that are pretty rough and look like metal was splattered on them (all four)...not sure if this is normal or not.
2) I pulled valve cover and rotated engine by hand and then with starter and all rocker arms/valves seem to cycle as one would expect. No parts seem bent or damaged.
3) I rechecked compression and verified that #4 was still zero. I checked # 3 just to make sure gauge was working and it held at 150PSI and pressure did not degrade for the few minutes I was watching.
4) Not sure what the probelm could be other then crack in block or bad head gasket at this point. If it was head gasket could it just impact one cyclinder?

Anyway let me know what you think!

Eric

[LaneRover]

Is there oil in the coolant at all?

[SafeAirOne]

If it was head gasket could it just impact one cyclinder?

Yes.

[bkreutz]

Since you've got the valve cover off.... measure the heights of the valves on #4 and compare that measurement with another cylinder. Make sure the rocker arms are loose when you measure them (rotate engine until you can "rattle" them. If the height is not the same I'd suspect a bent valve, even though you can see the valves move with a borescope, it's almost impossible to verify sealing using that method. It doesn't take much of incomplete valve sealing to cause this (another possibility is a burnt valve which would be hard to see unless the burnt spot aligned with your borescope). I think the next logical step is to take the head off and inspect, you've done about all you can do short of pulling the head.

[I Leak Oil]

Zero compression should yield an obvious failure once the head is off. Even with a sligthly blown gasket or a sligthly burnt valve you should be getting a little compression reading with a standard compression test.

[mongoswede]

Unless I missed reading it again: You could put an air line on the compression check hose and then put compressed air into the cylinder at TDC. If you hear air out the exhaust its an exhaust valve problem...intake = intake valve, air out the oil cap or PVC = rings. side of the block could be head gasket.

[HybridIIA]

I'm not sure how well you could see the valve heads with the borescope, but I suspect you have a badly burnt valve.

[o2batsea]

The good news is that repair for a bad valve or broken spring is pretty simple. A holey piston or busted rings on the other hand may be a death blow especially if the bore has scored beyond salvation.
You can still buy Bobeck's Iron Duke Chevy conversion that he pulled out of Red Square. It is a Robert Davis kit that was in there for only a year or so before he went with the 200tdi. Very low miles on it and a real improvement in performance. More or less a drop in replacement for the Rover lump.

[achtung]

Go get a leak down tester and use it, this will end the speculation.

[Moat Creek]

Did a little more investigation tonight

1) No coolant in oil
2) No oil in coolant
3) Ran vehicle for awhile and coolant level never went down & no bubbles.
4) Exhaust does not have condensation or unusal smell
5) Ran motor until hot and ran 140 PSI into cylinder # 4 and never could stop air from leaking out exhaust. Rotated engine by hand and could never find a sweet spot where the valves sealed #4. No air bubbles or surging in coolant.
6) Measured valve height on # 4 and compared to a couple other valves when closed and rocker arm had some slack. Exhaust valve height measures .035 less then intake valve.
7) Measured all tappet clearances and they were all .012-.017 except exhaust valve on # 4 which was .032.

I guess next step is to pull head this weekend and verify that #4 exhaust valve is burned/bent or other wise damaged. Once I get if off I will have to sort out if it makes sense to get a rebuilt head or some lesser fix..... let me know if I missed anything. Is it possible to just replace valve if valve seat is not damaged or is my only option to have mine rebuilt or order a remanufactured one?

One good find was gas was spitting out of my rebuilt BV carb where the two halves of carb meet (I had compressed air running in #4 & intake valve was open). Looks like I get an oppurtunity to fix another possible vacuum leak source & may need to adjust float agian :)
I just replaced that gasket when I installed correct jet.... I knew the paper based gasket wasn't as good as a impregnated/fiber one. I guess I will have to find a good source for a new one.

Thanks again for your input!

Eric

[SafeAirOne]

Is it possible to just replace valve if valve seat is not damaged or is my only option to have mine rebuilt

If the valve seat is good and your valve is just sticking, you can just have the one valve and the guide and its seal replaced, but If it were me and I had the head off and at a machine shop anyway, I'd just have them do a complete valve job and replace all 8 valves, guides and seals. No point in doing this again in 6 months.

The only counterpoint might be if you don't have an unleaded head, you may choose to go that route instead.

[o2batsea]

Remove the cylinder head. I'd plan on sending the head out for a rebuild. Have them install the hardened "no-lead" exhaust valve seats. You will want at minimum new valve guides and seals and have the valves relapped. I'd also pop for new springs. Don't allow them to skim cut the head unless they are absolutely positive it has a warp.
That should take care of the head.
Your main worry is the engine block. If the #4 piston bore has been scored or damaged in any way the engine will have to come out for repair. You will see and be able to feel by running your finger around the inside of the bore. If it is at that point where it needs an overhaul you will have to determine if your wallet and gumption are up to the task. No matter how you slice it it's at least a $3000 job, whether that is cash or labor or time or a combination of all three.
If you spend that and still have a $4000 truck, I'd begin to rethink the worth of pursuing the whole business.

[I Leak Oil]

I guess next step is to pull head this weekend.....


I think that's been mentioned a few times already.;)

[4flattires]

I'm just coming up for air after working on a shower remodel (ok and windows too), so getting up to speed on this post.

Hey...so since the head is coming off...how 'bout some pics?

I'll check back in 15 mins so we can see what the culprit of #4 is. :rolleyes:

[achtung]

I'm just coming up for air after working on a shower remodel (ok and windows too), so getting up to speed on this post.

Hey...so since the head is coming off...how 'bout some pics?

I'll check back in 15 mins so we can see what the culprit of #4 is. :rolleyes:

Better to just sit at your computer and click refresh all day.:popcorn:
Seeing as the valve clearance is greater on that cylinder I am suspecting some obstruction on the seat.

[Moat Creek]

Well I pulled the head off the engine and things did not look so good....poor rover. (see attached PDF file)

The good news is the head gasket was in terrific shape and not the cause of the lose of compression :). The exhaust valve in #4 would not close all the way so that is probably the cause of the zero compression I suppose.

Looks like a piece of the piston was bounced around in #3 & 4 before becoming embedded in crown. Not sure I have ever seen pistons look like this before. The head cannot be reused since the pitting is so deep that machining would remove to much material. The cylinder walls look surprisingly good and are not damaged (all 4 show mild signs of wear).
I measured the diameter at the top of the cyclinder (don't have proper gauge to measure further down) and from what I can tell from the green bible the block should be able to be bored out or have liners installed.

Not sure what I will do next. I can order a rebuilt head but finding a engine rebuilder in LA area is real difficult. No local supplier in area has rebuilt engines so I would need to order one perhaps from our host...shipping would be costly. I guess I can also take the craigslist route & try to find a good used engiine but that would take time & could end up with different issues unless it was recently rebuilt. Much to think about.... after a 1.5 years of complete teardown/rebuild of my rover freind I am getting real anxious to get it back on the road.

Thanks for all your input!

Eric

[VTBKRDS]

Your engine is SPANKED. Save yourself the aggrivation and order the reman. from our hosts. Having seen many blown engines, this one will require a MAJOR overhaul. Once you pull the pan, you'll find the piston pieces down there and possible crank and rod damage. You will have as much, if not more $$ into repairing this one, than just getting the reman.. That's if you do find a reputable machine shop to help you out. (my 2 cents) Good luck.

[Apis Mellifera]

I'd disagree with the engine being a total loss. I've seen that kind of damage before. I once supercharged an MG Midget I had and something was sucked in and bounced around inside cylinders 3 and 4. The only reason I noticed was that it developed a misfire because the plug gaps were peened shut. The pistons looked much worse than yours. I put the engine back together, replaced the plugs and it kept going for years and years.

I don't think that piston fragments did that damage. They are aluminum and I don't think an aluminum shard would affect the cast iron head like that. I'd guess something was sucked or dropped into the carb or parts of the carb broke off. My first thought was that the rings broke, but the cylinder walls look OK. You could reuse the head. Remove the sharp spots to stop detonation and don't worry about what isn't cleaned up by a head skim. I'd have it magnafluxed, though.

Clean the head up, new pistons, new valves were necessary, new head gasket, and keep driving while you look for a good replacement engine.

Buying a rebuilt engine would be my Plan Z.

I'd take that valve out to see why it's hung open. Perhaps some of the debris that caused the damage is still trapped there. Is there debris embedded in the top of piston #3? Will it come out and is it magnetic? There looks to be what appears to be the electrode from a spark plug stuck in there. The valve sticking could be unrelated to this damage. Perhaps in this Rover's lifetime someone did this and you only found it now because a chunk of carbon broke loose (which is not uncommon) or normal deposits on the valve have made it stick. Had this valve been open for a while, it would be burned or possibly flame cut.

[albersj51]

I agree with Apis...the cost of the reman engines is pretty steep. Tear it down and see what the machine shop says. A major overhaul will likely be a lot cheaper than the remans.

I think there is a "recently rebuilt" 2.25l on landroverexchange.com right now.

[achtung]

I had a motor lose a couple valve seats and break a piston 2 years ago. I sent the heads out and had them rebuilt, then I used a ridge reamer and cut the ridge off of the block and removed all the pistons by way of taking off the oil pan and sliding them out the top of the motor. I honed out the cylinder walls and replaced all the rings and the one broken piston. Then I reassembled the motor without ever having taken it out or the car. I drove the car like that for another year until I got the money together for a proper rebulid. This was not a daily driver and it still consumed some oil but if your looking to buy yourself some time you could try going that route.

[Moat Creek]

I saw the rebuilt motor for sale on LR Exchange. Seems like a good option since he has a TDI to install. I guess only defect is rear seal leaks some (about 1 qt per 1500 miles). Do you have to pull crankshaft to replace?
According to the green bible it looks like a <4hr job and can maybe be performed my a hack like myself. Price seems reasonable & less then 1/5 of the cost of a reman engine.

I am in the process of selling my house and not sure if where I am going is going will have a lot of garage space so having someone do the work or buying a used engine is best option for my situation. Down the road I want to get a diesel engine when I have time to tear up rover again.

[bmohan55]

the PDF looks famliar.....

Mine was a broken ring from #1 cylinder that migrated to #4 and chewed it up. Head wasn't damaged as I shut it down as soon as the racket started. Pulled engine and bored out to .03 over with new pistons, bearings, ect. Almost back together, parts & shop work were about $1,100 and I paid a friend $500 to do it with me watching/helping/pestering.

thought about just going with a different engine but now I know mine is correct with no issues on the horizon.

Good luck!

[smukai]

I think I would hit the ESC key.

(photo courtesy of Anthony Sloan)

(and yes, I know I bring nothing to this conversation)