Sandy Gibson

It was old (but unused!) oil I used for toe initial start up as I intended draining it soon after I had done a few miles to settle everything in so. No sign of any contaminant when I put it in so don’t think that’s the problem. I did wash the engine down weeks before re-assembly but blew all the chambers out with compressed air plus it was rotated many times on the engine stand so I’m sure there was no water trapped anywhere. used a new rad cap for testing and polished the filler cap faces to try and guarantee a good seal.

They were fine. The engine was running really well. I’m guessing that pressure dropping to zero in 10 seconds is a significant leak and is more than I would get with a blown gasket.

Back from holiday and finally did a pressure test on the cooling system. First I drained the oil and used a new rad cap. Took pressure up to 7lb and it dropped back to zero in about 10 seconds. What I don’t understand is that there were no visible leaks and no water is draining from the sump. Also, and very strangely, after the pressure goes back to zero and I take off the rad. cap the water level seems to have risen! I’m thinking there might be a big air lock in the system (air compresses, water doesn’t) and that might explain the increase in water level and also air is escaping causing the pressure drop? Still no further forward in explaining my real problem of water in the oil. Really struggling with this one. Anyone got any more thoughts?

Thanks for that. A good outcome, hope I get as lucky!

Thanks Johny Is the overflow pipe not above the rubber seal on the rad cap and therefore not part of the pressurised system? Do you test with the engine running or pressurise the system by some other means? Thanks

Pete I looked at that test kit earlier but couldn’t see how it plumbed in. Would it screw into the drain cock beneath the manifold? I have seen rad caps with temp gauges but none with pressure gauge. Any idea who supplies? Thank you Sandy

Thanks guys. All suggestions welcome! I had assumed that a significant (whatever that is!) amount of water would be needed but if not, then I’m leaning back towards the gasket failing or more likely my stupidity somewhere!

I’m reluctantly coming round to the idea that it’s more than a gasket problem. I took a long time with this rebuild and I was pretty meticulous about getting everything right. Does anyone have an idea of how much water it would take to emulsify a sump full of new oil? The engine only ran for about 10 minutes from start up and I am guessing that even with a blown gasket, not a lot of water would escape. During that 10 minutes I did top up the header a couple of times but assumed it was because of air locks escaping from the system .

Thanks Pete Engine has been rebuilt after re-bore. After start up, ran for about a mile to warm up then ten minutes or so fiddling with timing. After that I checked the oil to find the horror! Have not yet taken the head off although that clearly needs to happen. The engine still runs and I am just wondering if there could be any useful checks I could carry out at this stage before the head comes off. One of my many concerns at this stage is that I take the head off and there is still no clue as to what went wrong! I bought the engine as a spare to rebuild. Only known previous issue was broken piston rings ( hence rebore). When I originally stripped it prior to the rebore, I did have a good look at the old oil and it seemed OK so I’m guessing it had no head/gasket problems. Thanks for your help Sandy

Thanks Clive. Bottom of the dipstick shows the problem!

Thanks Doug but definitely no tag on the gasket! Wondering if anyone can suggest any more tests I could run while the engine is still running and before the head comes off? Sandy

I’ll run it again tomorrow and see what develops. Good thought that the colour of the oil could be fine bubbles but it looks like emulsified oil to me! Sandy

Thanks for that Nick I sealed the timing chain studs and also a water pump one which went straight through but I didn’t know that the rocker cover studs could go through. I had the engine running with the cover off but didn’t see any water coming up. The bubbling in the header tank was more of a foam on the surface followed by some large bubbles. Might be air trapped in the system being released. I’ll run it a bit longer tomorrow and see what happens. Used mini spares flanged nuts on original studs but don’t think thread length was an issue. Sandy

It’s definitely a Mk3 engine and I can’t see any tags at the rear of the head. Attached a couple of pics of block and head prior to assembly. If the gasket has failed should it be obvious when the head is off?

Used a Payen gasket without any dressing. I bought the engine for repair. It had broken piston rings caused by a lip on the top of cylinder bores but no head problems as far as I know. Block has been rebored to +040 Other than a good de carbon and polish the ports, didn’t touch the head

Just fired up my mk3 engine after rebore. All went well, good compression, water circulating but when I checked the oil it’s very milky. Also bubbling through the rad with the cap off. Thinking of taking the head off, getting it skimmed and trying again with a new gasket. Does anyone think this should be the way ahead? Alternative is to pull the engine and I haven’t really got the time (or the enthusiasm at the moment!!) to do that. Any advice would be much appreciated. Thanks

“Borrow” the wife’s nail polish remover! Works a treat!

Perhaps the low compression version was for US market only?

Thanks Doug. Interesting but not sure about that one. I thought all Mk3 engines were FD prefix? My existing engine is FD and ending HE as well. Can’t believe two ex US engines have found their way to me!

Hi Folks I bought the above engine and am presently re-building it as a spare. Don’t know anything about the history of the engine or the reg. no. of the car it was in. Was wondering if there was any way more information could be traced using the engine number on its own? As I bought it it had already been bored out to +030” and the crank to +010”. Thanks for any thoughts Sandy Gibson

Colin. Many thanks for that. I’ll send them dimensions to be on the safe side but that appears to be the part I need. Don’t know either of those companies. Good find Thanks again Sandy

Does anyone know where the above might be available. Have tried all the main Triumph suppliers but all list the seat as NLA. Previous owner must have lost the seat and just put the head together without one. Presumably it ran OK but it would worry me knowing it wasn’t there! I’ve made one up out of two washers welded together but would prefer to get the correct part if possible. Thanks Sandy

Thanks all. Think on balance I’ll just replace the pins as well. Budget went out the window long time ago so might as well err on the side of caution!

Hi folks I’m going from +030 to +040” pistons on my engine rebuild. Got a good deal on new pistons but without gudgeon pins. Old pins are good. Anyone know of a reason why they shouldn’t be interchangeable with new pistons? Thank for all help.

Thanks Mathew but I’ve completed the body off part and in the middle of a spare engine rebuild just now. Wish I had seen your section last year. It would have saved me a lot of work. Might contact you again in the future if I have the body off again though. many thanks