Need help with my Spit/GT6 conversion.

[Yakooza2]

Hello people

I am a newbe to the this site, but not new to triumph Spitfires and GT6s.

 

I am now faced with a number of baffling issues with my recent project.

 

Just to give a background, I bought a Spitfire 4 1500 at about 5 years ago. Since then I bought a so called Reconditioned GT6 engine and gearbox from an old enthusiast. The engine came to me as complete unit and assembled, but I had to source H6 SUs, new radiator for a GT6, and a few other bits.

Had a couple of issues with the original torque settings, but finally got the whole thing fired up a few times for a short while and found the system over heating and water shooting out from the outlet to the bottle.

 

I have since removed the thermostat for better water flow, fitted a new 13LB rad cap, reset the timing as per workshop manual, checked and reset all the valve clearances and done the best I can do to tune my carbs with help from airflow meter and new set of plugs too to good measure.

I also have an electronic fan fitted, which I have switched to run permanently from the start for the purpose of checking the outcome.

 

Having restarted the engine from cold, after carrying out all of the above, I seem to have made little  or no difference to the situation.

 

There is no water leaks and the engine starts fine and runs for say 10 minutes at 1000 revs, then it is noticeably hot and the engine begins to slow down a bit and struggles to keep steady revs. If i start to press the gas pedal, the carbs spit back and and engine begins to die down. very hot by then.

 

The temperature gauge just registers on 1/4 mark throughout, but that maybe another fault (electrical) possibly. But trust me the engine is very hot for that short period of time with the fan blasting from the start.

 

Before I started to write this, I read a lot of comments here on this site with regards to head gasket or head being a problem.

 

I am now wondering, if the engine was a real reconditioned one, or was it it just washed and painted? The seller was a real genuine sort (at least that is how he appeared) or was he just sloppy with his work and something else is wrong with my engine settings. 

 

I will do a compression test and will check for the bubbles on the radiator before taking the head off.

 

Is there anything I have missed or overlooked here?

Your help will be most appreciated.

 

Nader 

[John Bonnett]

Hello Nader,

 

Just a couple of thoughts. I don't think it is ever a good idea to run without a thermostat. That will not help the cause. I think it might be possible that there is an airlock if the gauge is showing a very low coolant temperature. It does appear that you don't have any circulation. Is the radiator blocked? The engine must have been close to seizing through over heating so it is possible that damage could have been done to the head and the gasket as a result rather than being the primary problem..

[Clive]

Which needles are in the HS6 carbs?

What is the engine number (or at least the prefix, the 2 letters at the start)

The radiator you say is new, so should be fine?

Have you checked the engine is not clogged?

 

 

I know I am asking questions, but "we" need to know where we are starting from.

 

I was there, spoke to you briefly before I had to dash off. (I was the chap who pointed out the Admin chap from he other Triumph Club)

 

I seem to remember you have a T2000 distributer fitted? That should be fine, but check the mechanical advance is working OK as you rev it.

[Pete Lewis]

And can you get a compression check , all plugs out and throttles opened

 

pete

[Dick Twitchen]

Nader,

This sound like clogged-up waterways in the cylinder block for it to react this way whilst stationary.  Try the simple test of opening the block drain tap, if nothing then remove it or the plug; if still nothing then a prod around with some brazing wire may clear something.  If still nothing 'search' the forum as I seem to recall a thread on this or a similar problem.

Dick

[KevinR]

Not withstanding any over heating problems etc, have you uprated the braking system to use GT6 front and rear brakes ?

[dougbgt6]

If you've "reset the timing as per the workshop manual" it will be at 13 degrees BTDC, which is too much. This was for old fashioned 5 star fuel which is long gone. This won't be the root cause of your problems but will add to them.

[Yakooza2]

Thank you all for your quick responses. Had a sleepless night just thinking about all possibilities.

 

Radiator is reconditioned and tested before fitting.

Thermostat was removed just to eliminate that as the possible cause, it will have a new one fitted, once I get to solve the problem.

The engine came with the distributor fitted, so I have no idea it was not the original, so I will be checking that too.

The needles on the carbs, I am not sure, the carbs were purchased on ebay, from a triumph 2000 I think.

Compression test will be done today, if I can get the right plug adapter (bought a cheap test kit on line with odd fittings) probably Chinees import.

 

This has been a long and slow rebuild with lots of parts from similar triumph parts over the last 5 years.

 

The reason I suspect the quality of the engine build now, is that on starting the engine for the first few times with the car still in the garage and in a shell state, the engine slowly developed a knocking sound after a few hours around the distributor area.

Since the distributor was the last thing I fiddled with (setting the timing on cyl 1) before the noise started to increase, I stopped and at that point taking the distributor completely out to check where I had gone wrong, that is when completely by coincidence, I could see the end cap of the con rod no 3 showing a gap of 1/4 inch. The bolts where coming off.

 

So I pulled the engine out again and checked the bolts on all con rods and main bearings to find that they had not been torqued up to specification !!

Hence my earlier comment, that I think it was a wash over job on the engine and not a proper rebuilt.

 

I am now beginning to think along the lines of damaged head /gasket or cylinder liners being cracked, now that I know they made a mistake on the crank assembly, what else is done wrong. I just took the man's word, when he said it is all done and reconditioned, when I was buying the engine from him. silly me.

 

But I will do the compression test first and do the engine flush before taking the head off.

For now, I am hoping it is only a head gasket job.

 

Thanks again for all your help, but watch this space, and I will update you with some photos of what I find.

 

Nader

[Yakooza2]

If you've "reset the timing as per the workshop manual" it will be at 13 degrees BTDC, which is too much. This was for old fashioned 5 star fuel which is long gone. This won't be the root cause of your problems but will add to them.

 

​A very interesting point, I did not think of that. but I took the information with regards to the timing and so on, from a similar forum and the information was;

Idle 700-900

Static 6BTDC

At Idle 4ATDC

Gap points 0.015

My engine number is: KE971HER

[Yakooza2]

incidentally, given the engine number KE971HER, does anyone know which head gasket I must buy?

There are a few with varying prices about and some mention (recess). I am not sure what to look for.

 

If I have to get the head off, I like to make sure I have the correct head gasket to hand to replace, in case what was fitted was the wrong type and the cause of all my problems.

 

Nader

[Clive]

the R at the end means it has been reconditioned (possibly factory??)

 

KE means GT6 mk3, and low number means an early one that is non-recessed (recessed gaskets have a tab sticking out at the back)

 

Best is a payen gasket, worth the extra £ or 2, they are about the best you can buy.

 

Dick made a good point about water flow through the engine, worth flushing out (but as your rad is new, take the hoses off so you don't get crud in the rad!) The engine drain blck is under the exhaust manifold near the back of the block. Take off the thermostat housing, heater hoses etc and put a hose pipe to each in turn. The block drain just press the hose to it firmly, it should get muck out, but often needs prodding to get things started.

 

Check the needle numbers, std 2000 ones may be OK, depends if the original fitment had the very thin (restrictive) airbox or not. If it did, they will be too weak above idle (but should be OK up to 2000 rpm ish) Timing too retarded will cause excess heat too. Set to 10 degrees BTDC with a strobe (vac line disconnected) as a rough start point, and tune by ear. ie drive, if it pinks retard the timing a little, if it doesn't, advance it until it does, then back a smidge!

[dougbgt6]

Yes, what Clive says, an early mk3 engine, here is a good site to check details.

 

http://triumphspitfire.com/historyG3.html

[Steve P]

Not much help now but if you had it apart to re- torque the bearing caps you could have checked for a crank regrind and new shells.Did the pistons and bores look newish?

Steve

[Yakooza2]

Hi Steve

Yes you are right, a bit too late now, but I was so excited to have found the cause of the problem at the time, I did not bother to look further. But with the head off (after all other tests) I should be able to have a better idea. The shell bearing did not look new, but I put that down to it being loose for a while and being knocked about, until I saw it.

If it's any help, I did fit an oil pressure gauge and it reads around 60 at start and goes down to 40 when hot at idle. that is good I think!

 

Thank you Clive, some really good points, I now remember the same advice given from my instructor in Waltham Forrest Technical College back in 1975 when I used to buy and tinker with all sorts of Triumph cars, whilst studying Mechanical Engineering.

 

and a big thanks for clarifying the head gasket identification and engine numbers for me.

 

Had a big breakfast now and waited for the rain to stop, so off I go to do the checks and report back later this evening.

[Yakooza2]

All test done, nothing changed. So off came the head and I found something that I like to share with you all and ask your opinion, but I seem to be unable to upload photos, possibly because I am still a newbe.

 

Please have a look at this link for photos of GT6 cylinder head on line and let me know why there are two different size oval holes at each end of the head?

 

https://www.google.co.uk/search?q=triumph+gt6+cylinder+head&espv=2&biw=1366&bih=643&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjSqpWG7aLNAhXHUBQKHSZICzMQ_AUIBygC#imgrc=ZU6bM8v6xbnxPM%3A

[Pete Lewis]

From memory these two kidney shapes are just coolant flow

 

I expect you may be using new shells following the rattling good fit rebuild.?

and take great care and double checks when setting the cam gear timing, the 4 gear holes are indexed to give 1/4 tooth increments, use a dial indicator to get exact lobe tdc , measure lobe lift at equal point btdc and atdc of the lobe and half it to be dead centre

becase there a lot of cam rotation with no lift when cam lobe it tdc

Pete

[Yakooza2]

Hi Pete

 

You are right, they are kidney shaped water ways. But the strange thing was, that the head had one end kidney shaped and the other end just a single 1/2 inch hole.

Checking with the pictures on google, they seem to show both but no explanation why or what is the reason for the two possible option.

 

So I took my drill and enlarged the 1/2" hole at the rear of the head nearest to no 6 cylinder, to as close to kidney shape as I could. It can only be a good move as far as I can see it, it should allow more water flowing, Right?

 

Thanks for the tip about the cam.

 

By the way, do you know how I can share my photos here with you guys?

 

Nader

[Pete Lewis]

select other posting options   at base of post 

 

scroll to browse file    click box.

 

pick photo from your file  and click  open

 

click attach this file    done 

 

 

 

and it should work ok  there is no file or photo size restriction 

 

 

Pete

[Yakooza2]

Hi Pete

Thanks for that

 

here is the photo of the head and gasket.

 

I think the head is a little warped in the middle, so its off to be pressure tested and skimmed.

 

Hope this will solve the over heating problems.

 

Nader

[Yakooza2]

The head is back from the shop, passing the pressure test and skimmed by 9 thou. apparently it was warped.

New gaskets all around, new stat, all flushed water system and timing / all adjustment set to specification.

two extra holes made to the other side where there was only one, for better water flow.

If all this does not solve my over heating, I don,t know what will.

 

Any hints and tips for a smooth assembly will be appreciated.

 

Nader

[Clive]

All very straightforwrad (he said!) head gasket dry, except a TINY smear of sealant around the oilway that feeds the rockers both sides of the gasket. The feed is at the rear, on the passenger side of the block.

Male sure you reuse the correct hardened head nuts and matching hardened washers. Normal washers will slowly deform and not hold the head down tight enough.

[Yakooza2]

Fitted the head and done all adjustments. 

Ran the engine for 2 minutes, then disaster. Water was leaking from the side of the head along the gasket line. so re tighten the head bolts and it slowed to a trickle. water found its way down the push rods too. over heating still the main issue.

 

Have I over looked anything? should have used gasket seal on both faces of the gasket !! 

Head is back from the shop and skimmed, so that should be good. But what about the block face? could that have been warped too?

 

Really scratching my head now.

Head got to come off now, oil will have to be drained and a new filter with new oil to go back in not to mention new head gasket.

 

Any ideas any one? I was looking forward to take the car out this weekend, but frustrating as it is, I am not ready to give up yet.

 

I need all the help and advice I can get, so come on guys put your technical caps on and lets get this old girl back on the road.

[Yakooza2]

Well, the head went on and torqued down to specification and all adjustment done again to start the engine, but this time it was worse, the water was visibly leaking from the gasket area between the head and the block just behind the exhaust manifold at cylinder 3&4.

 

I went a bit OTT with the torquing of the nuts and it slowed to a trickle. but still over heating.

Frustrated with outcome, I took the head off again and I think its partly the gasket to blame.

I got hold of a straight rule long enough to cover all 6 cylinders and proceeded to pass filler gauge under the straight edge and each cylinder tops to see if the block face can be at fault too, and it was.

 

At cylinder 2 to cylinder 5, I could pass a 5 thou filler gauge at ease.

so I had to rub the face of the block with a hard flat  block and emery cloth of various gauges, to get a near even finish across all the cylinders. still a gap, but less than 2 thou.

 

Now my question is, how do I know to buy the right head gasket and the right quality if not from Rimmer?  Rimmer Brothers show two types for the same engine, GT6 MK III

with marginal cost difference. so I am a bit weary now of making the same mistake again with the choice of gasket.

 

I do hope now that I have had the head worked on and the block sorted with all the new gaskets (head gasket yet to be obtained) and thermostat, the over heating would be a thing of the past, otherwise    ,,,,,,,,,,,,,,,,,,,   I have to start all over again.

[Last_Vitesse]

Hi I have used a milton keynes firm

GASKETS for CLASSICS 01908 - 366435 (Mon-Fri - 8.30am - 5.30pm) they have an ebay store, they only make gaskets and are very helpful.

Give them a try, good luck.

Regards Mike

[Yakooza2]

Thanks Mike

 

I bought the correct gasket from Moss and the engine went all back together and the situation improved a tiny bit, but I am beginning to think I am barking up the wrong tree (so to speak).

 

A quick recap,

The block face and the head face have been skimmed, all water ways are flushed and tested running clear, pump works ok, engine starts and runs sweet from cold and revs up ok, but after a short run at a steady speed, it heats up. about 5 miles or so, then the water pushes passed the new radiator cap and into the bottle and out all over the place.

I have an electronic fan fitted that I have bypassed the thermostatic control part, so it runs all the time from cold start.

 

My oil pressure gauge reads in high 70LB, even when the engine is getting red hot. so I am thinking around the fact that a re worked engine and the tolerances are still too tight and I should be using a thinner oil than that of 20 w 50 that is in there.

 

I am also beginning to suspect the radiator efficiency, even though it is a reconditioned GT6 radiator. and the all stainless big bore exhaust also contributes to hotter engine running.

 

Has anyone changed the radiator to an all Aluminium alternative for better cooling? and if so to what type and size.

I think I will go down this route first before giving the whole thing to an engineering place to sort it out.

 

Any help will be most appreciated.

Nader