6cyl SWB?

[Bigj66]

1 hour ago, lo-fi said:

Just build a nicely webbed piece to pick up the existing holes on the block and extend back to the mounts on the chassis. 6mm plate with strengthening webs will do the job. Drilling new holes in the block isn't likely to end well where there isn't extra meat cast in for bosses.

One other thought.... If the oil filter arrangement is the same as the 2.6, will that not foul the left hand mount in that position? 

Also, before you get making anything, are you 100% sure you've got enough room to move it forwards that much without causing a major radiator headache, and you're definitely happy there's room to work on various maintenance chores once it's in?

Fingers crossed for the flywheel by the way. 

Ample clearance between the LHS engine mount and the oil filter. The idea was to drill and tap the 12mm plate not the block 😳 I can always tack weld a nut on to the rear of the plate so no big dramas there.

As for the radiator, although the measurements I took at the beginning suggest that it will be tight but doable, the only way I’m really going to know is when I get the engine bolted up to the box and refit the radiator panel. If needs be I can trim the rad panel to move the rad forward an inch or so but my aim is to not have to do that.

My gearbox and transfer box could do with a rebuild anyway so at the same time I’ll get the 6 pot bell housing fitted to it and do a trial run before I even contemplate getting the engine rebuilt.

Workshop is nearly finished now so hopefully I can make a start on the project in the next month or so although I also need to learn how to weld.....

[Gazzar]

The diesel fly wheel may suit better than the petrol, as it should be a lot heavier.

 

The extra weight gives it more momentum, and thus should reduce any lumpiness from the engine. Mind you, I always thought 6 pots were sweeter. I've had a couple, a Jag and a Datsun and they were smooth.

The heavier wheel reduces the pickup of the engine, but reduces the risk of stalling in compensation.

[Bigj66]

11 minutes ago, Gazzar said:

The diesel fly wheel may suit better than the petrol, as it should be a lot heavier.

 

The extra weight gives it more momentum, and thus should reduce any lumpiness from the engine. Mind you, I always thought 6 pots were sweeter. I've had a couple, a Jag and a Datsun and they were smooth.

The heavier wheel reduces the pickup of the engine, but reduces the risk of stalling in compensation.

Interesting point and as the original Rover flywheel was bigger to start with, things may just balance themselves out.

[Bigj66]

It would have been rude not to given the weather....

[Soren Frimodt]

Looking smart! No better way to enjoy the weather than an open top Landy!

[Bigj66]

What a drama this is turning into!

Diesel flywheel arrived this morning so straight out to the workshop to compare it with the 6 cylinder flywheel and 3.0 engine.

Diesel flywheel is larger and thicker and also has a protruding central boss which holds the spigot bush.

Had to remove one of the two dowels off the end of the crank just to do a trial fit.

Offered it up to the crank but the protruding boss meant that I couldn’t get it to sit flush against the crank and I also noticed that the remaining dowel position on the crank was slightly different to the diesel flywheel hole. Using the flywheel spacer I was able to see how much it was out but more importantly, that the bolt hole spacing was correct.

You can just see the slight overlap between the spacer and flywheel dowel holes.

With the 2.6 flywheel housing fitted the diesel flywheel will not fit but with the Rover flywheel housing fitted the diesel flywheel fits okay. I’m not sure if the petrol flywheel is the same diameter as the diesel one and closer to that of the 6 pot LR but don’t have one to hand to check. I’m also not sure yet to what extent the petrol flywheel has a central boss as the diesel one does or what the impact of machining the boss down flush with the face would have on the functionality of the spigot bush itself?

It seems that I just need to experiment with different flywheel and flywheel housing combinations to arrive at the solution although it might end up that there is no solution. One possibility if I need it would be to reposition the bellhousing studs to match up to a suitable gearbox but there’s still some investigating to be done before get to that stage.

 

[Bigj66]

I’m wondering if the four cylinder bellhousing is larger than the six cylinder and if so would it fit to the original Rover flywheel housing?

[Bigj66]

3 hours ago, Bigj66 said:

I’m wondering if the four cylinder bellhousing is larger than the six cylinder and if so would it fit to the original Rover flywheel housing?

Scrub that, I’ve realised that I need to have a matched set of flywheel housing and bell housing due to differences in the starter position. 😞

Edit: Just found out that the petrol flywheel is the same diameter as the 2.6 but with the 8 bolt pattern which is good news as it means I should be able to use the 2.6 housing, starter etc. And the 2.25 petrol clutch.

Only thing I can see is that the spigot bearing hole is proud of the face of the flywheel by 5mm. Looking at photos of the 2.25 petrol flywheel, it seems to have a similar raised area.

The total depth of the spigot bush is 20mm so would it be okay to have both the bush and the flywheel machined so that the 5mm is removed and the flywheel will sit flush with the crank? Is the end of the input shaft that sits in the spigot the same length as the bush itself and if so would I also need to trim 5mm off that or is it the case that the input shaft is longer than the bush and needs to fit in the crank hole?

As always, any info appreciated.

[Bigj66]

2 hours ago, Bigj66 said:

Scrub that, I’ve realised that I need to have a matched set of flywheel housing and bell housing due to differences in the starter position. 😞

Edit: Just found out that the petrol flywheel is the same diameter as the 2.6 but with the 8 bolt pattern which is good news as it means I should be able to use the 2.6 housing, starter etc. And the 2.25 petrol clutch.

Only thing I can see is that the spigot bearing hole is proud of the face of the flywheel by 5mm.

The total depth of the spigot bush is 20mm so would it be okay to have both the bush and the flywheel machined so that the 5mm is removed and the flywheel will sit flush with the crank? Is the end of the input shaft that sits in the spigot the same length as the bush itself and if so would I also need to trim 5mm off that or is it the case that the input shaft is longer than the bush and needs to fit in the crank hole?

As always, any info appreciated.

Sorry, one further question about fitting a 4 cylinder flywheel to a 6 cylinder engine....timing marks, will I be unable to use the timing marks on the four cylinder flywheel and if so will I just revert to using the crank pulley to set things like TDC or to time the engine?

[secondjeremy]

The 2.6 S3 6 cylinder I worked on the other day seemed to have a full set of timing marks including the EP mark on the front pulley/damper.

 

Otherwise you'll have to compare the available marks on the 4 cylinder flywheel with what's required for the 6, assuming it fits in such a position that the marks are true.

 

With regard to the spiggot the issue will be does it prevent the nose of the first motion shaft from goung far enough forward towards the crank when fitted.  Some measuring may solve your problem.

[Bigj66]

42 minutes ago, secondjeremy said:

The 2.6 S3 6 cylinder I worked on the other day seemed to have a full set of timing marks including the EP mark on the front pulley/damper.

 

Otherwise you'll have to compare the available marks on the 4 cylinder flywheel with what's required for the 6, assuming it fits in such a position that the marks are true.

 

With regard to the spiggot the issue will be does it prevent the nose of the first motion shaft from goung far enough forward towards the crank when fitted.  Some measuring may solve your problem.

Thanks for the info 👍.

 Thinking this through a bit more, if I trim the raised part of the spigot bush off the flywheel centre then in effect I will be moving the flywheel 5mm away from the gearbox and so the FMS, being attached to the gearbox, will remain in its position but will sit 5mm rearwards of the flywheel and the clutch will sit 5mm further away from the box on its splines.

The position of the FMS is fixed by the bell housing and the flywheel housing depths which are standard sizes so the question now is, will moving the flywheel and clutch plate 5mm away from the gearbox have any detrimental effect?

One other thing that may affect the outcome would be if there is any difference in the depth of the 4&6 cylinder bellhousings or the thickness of the 4 cylinder petrol flywheel compared to the 6 cylinder one as that could increase, decrease or have no effect at all on the position of the FMS.

Only other option would be to open up the hole in the crank to accept the boss on the flywheel but the outcome would be the same.

I could really do with a big pile of parts to mix and match and experiment with 😐

[Bigj66]

I’ve decided not to remove that raised area on the flywheel as it helps to centre the flywheel correctly on the crank. What I need to do is have the crank centre hole opened up to accept the boss on the flywheel instead.

 I just need the 2.25 flywheel to be about 5mm thicker than the 2.6 one now. 2.6 is 35mm.

[Bigj66]

Turns out the 2.25 petrol flywheel is the same thickness as the 2.6 so I’d still be left with it further towards the engine than it would usually be. Could this have an effect on clutch operation?

[lo-fi]

Why not have a 5mm spacer made up to pick up the boss on the flywheel and locate on the crank without modification? 

[Bigj66]

15 minutes ago, lo-fi said:

Why not have a 5mm spacer made up to pick up the boss on the flywheel and locate on the crank without modification? 

I did initially think of ‘filling in’ the recess in the back of the flywheel with a spacer to make it flush with the crank face but realised that the raised spigot boss is needed to sit in the crank and locate the flywheel. In addition to the central spigot boss the recess on the back of the flywheel also needs to sit over the end of the crank for the same reason.

If you were thinking about a ‘top hat’ style spacer I’m not sure how that would work with the crank hole being 18mm diameter and the flywheel boss 35mm diameter. Wouldn’t the thickness of the material required to make the boss push the flywheel further from the engine than the 5mm I need or have I misunderstood what you were referring to? 

[Bigj66]

Last chance saloon - I’m going to see if the crank off the P5 manual is directly interchangeable with that of the auto.

If not then the Softdash gets the restoration and the Series stays as is.

[Soren Frimodt]

Turning into quite the job it seems, would it be impossible to drill out 5 new holes in the flywheel you got from me? Are they not on a different PCD?

[Bigj66]

3 hours ago, Soren Frimodt said:

Turning into quite the job it seems, would it be impossible to drill out 5 new holes in the flywheel you got from me? Are they not on a different PCD?

Hej Soren.

The 2.25 petrol flywheel should bolt straight on and fit within your flywheel housing if I was to open out the hole in the crank flange to 35mm. Problem is that this would then move the flywheel 5mm further towards the engine and I’m just not sure what if any, effect that would have on the operation of the clutch push rod. Would pedal travel be affected or would there still be enough spline length left on the first motion shaft to allow the clutch to engage and disengage correctly given the flywheel would be sat further away from the gearbox 

Without having a pile of parts to experiment with its hard to judge. I’m told a manual crankshaft may be interchangeable with the auto one so I’m still investigating that option at the moment.

I was also wondering if the 3.0 Westlake head would fit the LR 2.6 block as a lot of the power seems to come from that (in addition to the additional cc)? Possibly the camshaft too if it’s a bit more pokey?

[Bowie69]

A 5mm spacer would be cheap to get made.

[Bigj66]

20 minutes ago, Bowie69 said:

A 5mm spacer would be cheap to get made.

The problem is that if I space the flywheel off the crank by 5mm I will lose the centralising function of the spigot boss to the crank.

[steve b]

How deep is the spigot boss on the flywheel ? How about a spacer with a spigot crank side and an appropriate counterbore flywheel side ?

What are the respective diameters?

cheers

Steve b  

[Bigj66]

8 minutes ago, steve b said:

How deep is the spigot boss on the flywheel ? How about a spacer with a spigot crank side and an appropriate counterbore flywheel side ?

What are the respective diameters?

cheers

Steve b  

Flywheel boss is 35mm diameter by 5mm deep. Existing crank recess is 18mm diameter by approximately 20mm deep. If I open the crank boss out to accept the flywheel boss the flywheel will move towards the engine by that 5mm overall due to the thinner 2.25 petrol flywheel compared to the original thicker 3.0 auto flywheel ring gear/TC with the smaller diameter boss.

This may well be ok if it doesn’t affect clutch function hence the original request for more experienced input.

 I don’t think the top hat solution would work in this scenario but happy to be corrected.

[Bigj66]

I’m not sure I’ve explained myself very clearly about what is concerning me about having the end of the crankshaft opened up to accept the larger spigot bush boss off the 2.25 petrol flywheel so I found a good YT clip from Paddocks and screenshot some bits that might help explain things better.

This is my crank where the flywheel attaches. This is from the auto 3.0 and has an 18mm diameter hole in it which is about 20mm deep.

This is a picture of the 2.25 petrol flywheel, same diameter as the 2.6 so should fit within the 2.6 flywheel housing.

The boss in the centre on the crank side has a 5mm raised boss within which the spigot bush is fitted. 

As I understand it the purpose of the raised boss is to centrally locate the flywheel against the crankshaft by sitting inside a matching recess on the crankshaft, in this case the 18mm one.

General overview of the flywheel and clutch arrangement.

My concern (which may be unfounded) is that by opening up the crank hole to accept the larger diameter flywheel boss, the flywheel and the clutch assembly that is bolted to it, will in effect move 5mm closer to the engine and may cause problems for the operation of the clutch. For instance the clutch friction plate moves along the splined section of the gearbox input shaft and one worry is that once the flywheel is fitted to the modified crank, the splined section of the input shaft will be 5mm too short and this may cause problems for the smooth movement of the friction plate on the spline.

Will things such as the operation of the release arm or the clutch push rod be affected and if so could I just use a longer push rod like one off a Disco to compensate?

Hope these photos help explain the concerns better and as always would appreciated any input or advice.

A manual crankshaft off a Rover may be a straight swap for the auto but I’m still trying to get confirmation of that. One other option is to fit the Westlake head to the standard 2.6 engine if it can be done.

[Gazzar]

I think you can just fit the head.

The 5mm spacer would work, though: if you trim the spigot on the flywheel to 2mm, have 2mm hole to match on the spacer, but turn the spacer from 10mm, so it has a spigot, 18mm, that fits the crank.

The spacer should then centralise on the crank, and centralise the flywheel.

 

Accuracy, of course, being essential.

[Bigj66]

1 hour ago, Gazzar said:

I think you can just fit the head.

The 5mm spacer would work, though: if you trim the spigot on the flywheel to 2mm, have 2mm hole to match on the spacer, but turn the spacer from 10mm, so it has a spigot, 18mm, that fits the crank.

The spacer should then centralise on the crank, and centralise the flywheel.

 

Accuracy, of course, being essential.

Cheers. Yeah I could see how that could work and I probably have an engineering company that could do that. If using a spacer I will then need to source flywheel bolts that are 5mm longer than standard. Does anyone know what thread size the flywheel bolts are? The 2.6 and 3.0 ones are the same length.