Timing help

[Nick Jones]

Don't don't don't use photobucket!  They have changed their 3rd party hosting policy quite recently (you can have it restored for a very unreasonable $400/year) and broken tens of thousands of forum threads in the process.  Can't see your pic either for the same reason.

Their site is horribly slow and ad-infested anyway should be boycotted to death!  I've removed all my pictures from their servers and deleted my account.

Note to forum admins.... if you want your threads to last and keep their pictures, host the pics onsite and don't force 3rd party hosting.

Nick

[Guppy916]

Okay thanks once again Nick , photobucket will be removed 

[JohnD]

Quoted from Nick Jones-

Don't don't don't use photobucket!  They have changed their 3rd party hosting policy quite recently (you can have it restored for a very unreasonable $400/year) and broken tens of thousands of forum threads in the process.  Can't see your pic either for the same reason.

Their site is horribly slow and ad-infested anyway should be boycotted to death!  I've removed all my pictures from their servers and deleted my account.

Note to forum admins.... if you want your threads to last and keep their pictures, host the pics onsite and don't force 3rd party hosting.

Nick

Hear, hear!   Admins - do you see how your policy is making advice for a member difficult to provide?

John

[Guppy916]

Hi guys, Do we think that non paid up members will be allowed to post photos in the near future, and the web site might speed up, it is so god dam slow at the moment

[Nick Jones]

George,

Suggest you start a thread on the Sideways forum and post some pics.  There are a couple on there with experience of trouble shooting mechanical mishaps on the 6 pot, who don't come here that often and you should find posting pics easier.  PM me there if you have any issues.

Very curious to see your pics - hot spots sufficient to blister paint in the places you describe sound like bad news to me 😭

I really don't understand why it has been deemed necessary to be a paid up member to be allowed to post pics directly to the site.  It wasn't the case on the old CT forum and the TSSC have seen the light and now allow non-members to not only post, but post pictures too.

Nick

[Guppy916]

Yes Nick , I’m thinking the new oil pump has

let go I hope to have the engine out and striped

over this weekend 

[Nick Jones]

Good luck - hope the damage is not severe.  Have heard of problems with the oil pump drive shaft becoming detached from the central rotor, though that usually causes 0 pressure.

Did you have ok pressure initially, even once warm?  Bearings one size up compared to the crank can cause very low pressure when hot.

Nick

[Guppy916]

Yes pressure was okay but started to drop

after 20 / 30 odd miles , I spun the car 

round and headed for home , I made it still  with

low 20psi pressure

[Guppy916]

right engine out, gear box still in car, what a shite job. just because i didn't want to to take the tunnel out! 

with the engine striped  the cam is totally knackered, Journals 1&2 show signs of scoring, 3&4, totally buggered. I shall have to get a new cam and a set of cam bearings, 

the big ends look okay no damage but I shall fit new one's anyway, The mains are still in I haven't removed them yet, 

I also noticed the lack of oil in with the timing chain which was almost dry, The oil is being filtered so i can see what debris is in it,  I haven't checked the oil pump yet but I shall replace it anyway, any body know where I can buy a quality pump ?

I think I read on our old site that some people enlarge the oil ways to the cam, but I have no way of checking that now, Sorry I can't post photo's on this new site, 

Also the thrust washer on the crank shaft is showing a lot of wear, I know when I rebuilt the engine the end play was very tight 4 - 5 thou, but thats what the book says to set it too, now its as slack as a yak ! 

 so either the pump is fu=ked or ive suffered with blocked oil ways,

right the good news piston and bores look great, so new rings and that will do, after all the engine has only done 80 ish miles 

So where to buy a cam and bearings from ?? I don't want a Kent one, because a friends went pear shape after a few miles the lobes blue out ( is that the right blue)?

the car is a MK3 GT6 with a 2.5 lump

advice please, ta guys

[Nick Jones]

First question..... and it's a key one; does your block actually have cam bearings?  These were not standard fit on any of the 6 cylinder blocks, with the cam running direct in the cast iron. In order to fit cam bearings the block has to be line bored.  Finding places that can do this is not very easy as the block is quite long.  Do NOT believe anyone who says they can do it in two goes from either end!

If your block does have bearings (and I would be surprised if it does) then you can change them but I'd also be checking whether the oil holes in the bearings were lined up with the oil holes in the block and whether the bearings have been spinning in the block.

If your block has no bearings then the big worry is the state of the bores that the cam runs in and I fear they'll be shot - meaning you have no choice but to get the block line bored if you want to save it.

Will be interesting to see the state of the oil pump......it may well be chewed up now having had to swallow whatever debris was falling into the sump, but as it gave good pressure initially it may not be the original problem.  Cam bearings as an initial failure point is odd, especially if the crank bearings are still fine.  What cam are you running and what valve springs - is there any possibility that the valve springs are excessively strong or were becoming coil-bound?  This can overload the cam journals and cause them to fail and the resulting wide open tolerances then cause a drop in oil pressure.  

Have no theory on the thrust washers - presumably it's the one on the flywheel side that taken the brunt?  Were they fitted the right way round?  (awful easy to get wrong.....)

Any engine rebuild, and especially this one, needs total cleaning of all of the oil ways.  This means an empty block, all gallery plugs out and the distributor drive bush out (as it sits in the main oil gallery).  Then it's out with the carb cleaner, rifle brushes and elbow grease until you are certain they are all squeaky clean.

You might find this helpful

http://sideways-technologies.co.uk/forums/index.php?/topic/5712-competition-oiling-draft/  (oilway mods and external feeds not necessary on road engines)

Nick

[JohnD]

May I add to Nicks Words of Wisdom?

Fitting the cam bearings isn't easy.  Best done with the right tool, so suggest you ask the machine shop that does your line bore to do it, as they will have the tool.  Rimmers sell cam bearings.

Most of the oil that is on the chain drive has escaped from the rocker shaft, but only from the front of it, dripping through the hole in the front engine plate, onto the chain and cam sprocket.     The front rockers notoriously get little oil if all the rockers, or the shaft, are worn, or the shaft is blocked with gunge, so suspect you need at least a new shaft.    And of course new  followers for a new cam shaft.

Is the crankshaft  still in place?  measure the end float - push the shaft to and fro longitudinally, with a dial gauge on the nose.  That'll tell you if an oversized thrust bearing will fix it.     There was a guy in the US making XXX oversized bearings to order, to avoid having to get the rear main welded up and recut - I forget his name, I regret.

I have a number of used cam shafts.   Tell me what you want and I'll see what I have.

JOhn

[Guppy916]

Ta guys, more measuring this week I haven't checked the rockers for clearance yet

Nick thanks for the link it was most interesting, no cam bearings fitted 

[Guppy916]

Guys can any body tell me if the TR6 and 2.5 blocks are the same thanks 

[Guppy916]

Right the block is in the engineering shop along with the crank, the crank is only having a check over to make sure it's okay, this has already been lightened  and balanced, the block is having it's internals cleaned, then the cam is being lined bored with new cam bearings fitted, a Newman fast road cam has been ordered, I just have to wait now, might as well go on holiday. hopefully this web site will be much improved by the time I return 

just a quick note 12:00 lunch time On Wednesday and THREE of us on line 

[Guppy916]

holy shite Five of us on line this must be a new record for the new forum

[Blanking Out]

Could someone advise me a bit re: timing sequence please? I always thought that it was 1,3,4,2 for a Spitfire (I've got a '79 1500), but I think mine might be set up for 1,2,4,3. Does this mean that someone's fiddled with it at some point and changed the sequence? Also, I'm not quite sure where the '1' starts on the distributor. I've been experimenting with the order and at one point thought I had it cracked - it started up and drove great with so much vigour (though I had just changed the ht leads and added N12YC plugs as opposed to N9YC). I started it up recently and that immediacy and vigour had disappeared. 

I think it's running rich, though, as well, because it takes no time at all for the plugs to become totally black and sooty.

Cheers,

Rob

[RobPearce]

Firing order is 1-3-4-2 on all Triumph 4-cylinder. Note that the distributor shaft rotates anti-clockwise. It's pretty hard to change the firing order as it's determined by the camshaft - if you just swap the plug leads on 2 & 3 you get an engine that may possibly run but only on two cylinders.

There is an officially correct place for the No1 plug lead on the distributor but it depends very much on how the oil pump / distributor drive gear has been installed. If that's ever been out then it could have been put back in the wrong orientation. So the best option is to set the engine to TDC No 1 firing (identify this by the valves on No 4 being "on the rock") and look see where the rotor arm points.

If it's running rich - and you need to have driven it up to properly warm before the plug colour is a good indication of that - then the plugs are probably fouling and your poor running may be down to that.