TR5 engine bay refurb - (front panel removal; exhaust manifold removal) - advice please

[TRbeginner]

Good afternoon all

I'm part way through what seems to have turned into a rolling restoration/general tidy up. Currently the 'rear half' of the engine bay (ie inner wings to bulkhead is undergoing some restorative treatment with body work, accessories, ancillaries etc being tidied up, parts replaced where appropriate etc. Before I start re-assemnbly, I am thinking about extending the work and advice in a couple of areas would be appreciated please...

1. Access to the front of the engine compartment is very limited, even if the bonnet is removed. Can any one offer advice please, whether it is easy (or even possible) to remove the front panel to provide better access/limt grazed knuckles so that I can continue the engine bay work. I'm assuming the front panel is 'bolt on' without any welds. The engine and ancilliaries at the forward end are all in situ and obviously would be more easily acessed without front panel, which itself is in excellent condition, just covered with almost 40 years of road grime. I feel a better job could be done with the panel removed. Currently panel gaps are good and I dont want to open a proverbial can of worms.

2. I am also fitting a new stainless exhaust/downpipe and am anticipating having problems loosening the nuts securing the existing downpipes to the manifold in situ. It may be easier to separate the two on the bench rather when fitted to the car. The manual says that the inlet manifold must be removed in order to remove the exhaust manifold. Is this the case even when all accessories around the exhaust manifold are already removed - I'd prefer not to mess around wth the inlet side, and it looks like all exhaust manifold nuts (7?) securing it to the head are accessible currently.

Any help on both the above would be great please. I have trawled the forum on both the above topics but cant find any directly relevant guidance. 

I'm learning fast and I may no longer be a TR beginner, but every job goes into new territory! Doing my best to understand each piece of work BEFORE diving in! Thanks for any information forthcoming - all very much appreciated.

Regards

Dave

[stuart]

The front panel is welded on (Or should be if original) dont try removing it unless you know what your doing to replace it and get everything to fit again, You do need to remove the inlet manifold to remove the exhaust manifold.

Stuart.

[TRbeginner]

29 minutes ago, stuart said:

The front panel is welded on (Or should be if original) dont try removing it unless you know what your doing to replace it and get everything to fit again, You do need to remove the inlet manifold to remove the exhaust manifold.

Stuart.

Stuart

Thats all I needed to know - thanks for the confirmations. Will leave the front panel well alone, and will give the exhaust manifold some thought - was looking for an easier way to separate the downpipe given the horror stories of freeing the nuts. Have just ordered some Kano Kroil - hope it lives up to reputation! 

Earlier this year you put me on to TR Bitz for a screen frame repair. Their body guy Noel did a very good job for a very fair price. Thanks for this too.

All the best

Dave

[Waldi]

I would remove the 3 throttle bodies, and clean/inspect them.

Check for play in the spindles, and if the gaps on the disks are the same when closed (idle screws removed).

Clean the bores of the idle air.

Also replace the bearings in the linkage system (3 off) by (blue) PU items, you are missing one now.

Use a good gasket, Payen seems to be the best many say on here.

I do not like a SS exhaust manifold for the additional heat it radiates but each to his own.

Work precisely, it will pay out.

Good luck,

Waldi

[stuart]

10 minutes ago, TRbeginner said:

Stuart

Thats all I needed to know - thanks for the confirmations. Will leave the front panel well alone, and will give the exhaust manifold some thought - was looking for an easier way to separate the downpipe given the horror stories of freeing the nuts. Have just ordered some Kano Kroil - hope it lives up to reputation! 

Earlier this year you put me on to TR Bitz for a screen frame repair. Their body guy Noel did a very good job for a very fair price. Thanks for this too.

All the best

Dave

FWIW It looks as if you have bolts instead of studs in the manifold flange so they should be easier to remove anyway.

Stuart.

[TRbeginner]

1 hour ago, stuart said:

FWIW It looks as if you have bolts instead of studs in the manifold flange so they should be easier to remove anyway.

Stuart.

 

1 hour ago, stuart said:

FWIW It looks as if you have bolts instead of studs in the manifold flange so they should be easier to remove anyway.

Stuart.

Yes, they are bolts. Every cloud has a silver lining! Thanks Stuart

[TRbeginner]

1 hour ago, Waldi said:

I would remove the 3 throttle bodies, and clean/inspect them.

Check for play in the spindles, and if the gaps on the disks are the same when closed (idle screws removed).

Clean the bores of the idle air.

Also replace the bearings in the linkage system (3 off) by (blue) PU items, you are missing one now.

Use a good gasket, Payen seems to be the best many say on here.

I do not like a SS exhaust manifold for the additional heat it radiates but each to his own.

Work precisely, it will pay out.

Good luck,

Waldi

Waldi, thanks for the tips above. Throttle bodies/gaps/boresetc are new territory to me - on any car! Very wary about stripping down further, but will take a close look - may as well while stuff is accessible. I'm not replacing the manifold, just fitting a stainless downpipe - when I read up on pros/cons of a stainless manifold there was enough concern expressed from folk much more knowledgable than me (heat, routing etc) to put me off! 

May get back to you about the detail around your suggestions if thats OK.

Thanks again.

Dave

[Waldi]

Hi Dave,

I’m glad to be of help (like many others).

If you use the “Brown Bible” and follow the steps in there, and off course ask on here if in doubt, the results will come. The Moss catalogue is a valuable source too. You will have to remove the throttle bodies anyway to replace the gasket. Take lots of pictures and make notes during dismantling.

Waldi

[TRbeginner]

18 hours ago, Waldi said:

Hi Dave,

I’m glad to be of help (like many others).

If you use the “Brown Bible” and follow the steps in there, and off course ask on here if in doubt, the results will come. The Moss catalogue is a valuable source too. You will have to remove the throttle bodies anyway to replace the gasket. Take lots of pictures and make notes during dismantling.

Waldi

Hi Waldi

Thank you. - the people on this forum are indeed amazingly helpful and friendly. 

The 'brown bible' being the workshop manual I presume, or am I missing something.....? 

Thanks

Dave

[stuart]

22 minutes ago, TRbeginner said:

Hi Waldi

Thank you. - the people on this forum are indeed amazingly helpful and friendly. 

The 'brown bible' being the workshop manual I presume, or am I missing something.....? 

Thanks

Dave

Strictly speaking thats the TR6 manual, though it pretty much covers all of the mechanical aspects of the 5, you really need a proper TR5 workshop supplement to the TR4a manual to cover it properly.

Stuart.

[TRbeginner]

On 11/15/2021 at 4:07 PM, stuart said:

Strictly speaking thats the TR6 manual, though it pretty much covers all of the mechanical aspects of the 5, you really need a proper TR5 workshop supplement to the TR4a manual to cover it properly.

Stuart.

Thanks for the clarification Stuart. I'll read up before I proceed.

[kpgarage]

Dave, good morning. Let me point out one thing which may be of help. Looking at your exhaust manifold picture, it appears that the factory studs have been removed in favor of four through and through bolts. That may ease the removal of the head pipe in the car. I’d soak those four bolts in PB blaster penetrant and then try to remove. Unless you just want to remove the exhaust manifold for clean up you could leave in place. The Triumph exhaust manifolds are really quite good and I’d be reluctant to change it to header or SS model, whatever it’s called over there.

[TRbeginner]

Apologies KP, I missed this message. Ive been soaking the bolts in Aerokroil lubricant every few days since Xmas (domestic stuff prevented further progress before Xmas), and only one has loosened. And Im not keen on the idea of using a gas torch at various precarious angles. The only other option appears to be to remove the exhaust manifold/downpipe combined and then split on the bench. I intend retaining the cast manifold, but already have a stainless down pipe. 

Can the exhaust manifold be removed without removing/upsetting the throttle bodies/manifolds etc?

 

[TRbeginner]

On 11/28/2021 at 11:29 AM, kpgarage said:

Dave, good morning. Let me point out one thing which may be of help. Looking at your exhaust manifold picture, it appears that the factory studs have been removed in favor of four through and through bolts. That may ease the removal of the head pipe in the car. I’d soak those four bolts in PB blaster penetrant and then try to remove. Unless you just want to remove the exhaust manifold for clean up you could leave in place. The Triumph exhaust manifolds are really quite good and I’d be reluctant to change it to header or SS model, whatever it’s called over there.

Apologies KP, I missed this message. Ive been soaking the bolts in Aerokroil lubricant every few days since Xmas (domestic stuff prevented further progress before Xmas), and only one has loosened. And Im not keen on the idea of using a gas torch at various precarious angles. The only other option appears to be to remove the exhaust manifold/downpipe combined and then split on the bench. I intend retaining the cast manifold, but already have a stainless down pipe. 

Can the exhaust manifold be removed without removing/upsetting the throttle bodies/manifolds etc?

[stuart]

You would have to strip the throttle bodies out as well Im afraid.

Stuart.

[TRbeginner]

Just now, stuart said:

You would have to strip the throttle bodies out as well Im afraid.

Stuart.

Thanks as ever Stuart, I was afraid this would be the case. The gas torch approach in those confined spaces and upside down scares the wotsit out of me - 40 years ago I probably would have not given the possible consequences a second thought! Self prervation seems to be an age thing! 

[TRbeginner]

Success!! After liberal quantities of Aerokroil, patience, a little bit of heat and unimaginable torque on a quarter drive extension I have successfully loosened the nuts and separated the downtubes from the manifold. As mentioned previously the original studs had been replaced by bolts. These were 5/16 unf, however the holes in the flanges will take 3/8 unf bolts for the re-assembly.

Interestingly there was no gasket present at the joint, and the exhaust wasnt blowing prior to dismantling! 

Accessibility is good at the moment, with various accessories removed, so I need to get the re-assembly right first time (no leakage at the joint etc) with the new stainless downpipes. So a bit of advice would be welcome please. In particular - would brass nuts be recommended over steel ones - research indicates that steel nuts on manifolds are prone to loosening. Also, do I need to use a jointing compound such as Holts Firegum? Any recommendations about re-assembly welcome please.

Many thanks

[Waldi]

I used brass nuts and just the gasket, no sealants. Carefully tighten all 4 bolts using copper slip or similar so the gasket is compressed evenly around the perifery.

I used the sealing paste for the pipe-in-pipe joints, with mikalor clamps. I do not like the U-bolt types as these deform the pipe.

Avoid mounting the sections under stress and be aware the SS exhaust will elongate quite a bit rear wards as it get’s hot. I gave the mounting points a bit of pre-set where possible.

Waldi

[TRbeginner]

Thanks Waldi, brass nuts and dry gasket sound effective and straightforward. The mid section of the exhaust is suspended on a fixed mount at the rear of the gearbox, so I was thinking about adding some flexible pipe between the downpipe and this section, to provide some 'give' in the system. The rear section, including silencer is mounted on a rubber hanger. Hopefully these together will overcome any possibility of expansion/vibration stress.

Thanks again and best regards

Dave

[ntc]

You have not good advice the inlet/exhaust gasket should be as follows head side smear with copperslip exhaust side smear with exhaust jointing compound or it will dry out and leak.

[PodOne]

1 hour ago, ntc said:

You have not good advice the inlet/exhaust gasket should be as follows head side smear with copperslip exhaust side smear with exhaust jointing compound or it will dry out and leak.

Hi Neal 

Hopefully I only want to assemble this the once. In the past I've always fitted the inlet and exhaust gaskets dry but then on the MX5 they were on opposite sides so the heat was not a big issue on the inlet side and had no issues.

Is your advice based on long term TR6 ownership? and is the exhaust paste applied to both the exhaust and inlet ports? Or just the exhaust ports.

Thanks

Andy

[TRbeginner]

3 hours ago, ntc said:

You have not good advice the inlet/exhaust gasket should be as follows head side smear with copperslip exhaust side smear with exhaust jointing compound or it will dry out and leak.

Hi Neal....just to clarify....are you talking about the exhaust manifold to cylinder head gasket or the exhaust manifold to downpipe gasket? I havent removed the exhaust manifold from the head. Thanks

Dave

[ntc]

38 minutes ago, TRbeginner said:

Hi Neal....just to clarify....are you talking about the exhaust manifold to cylinder head gasket 

Yes I thought that was clear and as for the other post only 40 years plus 

Regards

Neil

Edited February 10, 2022 by ntc

[YankeeTR5]

Can't say I disagree with Neil.   Its what we (my son and I) did on his car - a 74 US spec that we put a PI head on to bump up performance a bit.

I would also add, if you have the exhaust header separated from the downpipe, it is worthwhile to have the surface of the header facing the cylinder head skimmed by a machine shop.   On my son's 74 we chased an exhaust leak over multiple iterations of solutions and it was after finally having a completely smooth (with no pitting at all) and flat surface after having it skimmed that the exhaust leak went away.   

[Waldi]

11 hours ago, ntc said:

You have not good advice the inlet/exhaust gasket should be as follows head side smear with copperslip exhaust side smear with exhaust jointing compound or it will dry out and leak.

Hi Neil,
it works fine on my car, but I bow for your long term experience.

I forgot to mention I also flattened both mating flanges. When I dry-fitted them (without a gasket) I could slip feeler gages in the gap. If left like that, it would probably have leaked.

Waldi