Problems (to solve) with my LT77 and >3.5l conversion

TyroleanRover

Active Member
Dear community,

After some trouble at work, the P6 had to wait for its conversion until a few weeks ago.
Because my last threads are a few months old, I give a quick sum up what is going to be installed:
  • The short block is a 4.8 (i measured with a calliper)
  • The heads are standard 4.6 with piper springs
  • Pistons seem to have a high compression. Usually, the HC pistons for the 4.6 have a 9.35:1 CR but I guess mine could be a little more because of its valve notches cut in. Anyway I use a composite gasket
  • The camshaft is a Piper 270
  • the manifold is the standard rover one for 2x SU, only the ports where the carbs sit are already ported to 2"
  • Carbs are 2" HS8. (Usually, I thought the engine is a 4.9 and I do not want it to run lean on higher revs)
  • jets are 0.100 and needles BAW (new) to have a point to start from
  • headers are standard 3500S, the exhaust is stock too (stainless), there is a chance I will remove one of the silencers this year
  • Final setup should use the standard elbows with the HS8, and the SD1 Airbox with the bigger intake snorkel and maybe less restrictive air filters hidden in the airbox
  • Gearbox is an LT77
If you want to read through my last threads, here are all that are related to the conversion:
Wanted: LT77 Gearlever
To port-match or not to port-match? ...
LDV Pilot gearbox (R380) or LT77 17A
A FEW MORE PARTS NEEDED - SU HS8 Carburettors wanted

-----------------

Actual:

The gearbox and engine are in the car and the Rover on the hydraulic lift.
Some trouble occurred:

1.) the transmission tunnel is f****** narrow.
The LT77 touches the transmission tunnel, on the driver's side is only a few mm wide gap left.
I need to widen it with a hydraulic press to ensure enough space for movement of the drivetrain.

2.) I can't fit the the speedo cable. Acutally the space is that narrow that i would have to make a hole in the tunnel for the cable. If i do so, it would bend very hard.
Is there a connector available to have it attached at a 90° angle?

3.) I need a distance-shim for the propshaft.
The autopropshaft fits, but i would feel better if i install a shim. I read anywhere they are available already. May i get a link to a offer?

But the biggest problems of all so far.

The bonnet does not close with the HS8 carbs.
when the filler caps touch the bonnet, i would need 1,5 better 2 cm to close safely and provide space for engine movement.
I already invested a lot of time and effort in this solution so i don't want to give it up. I cant go back to HIF6, i needed parts of the linkage to try working on the HS8 and the manifold is ported now.
@RoverAlex used the same carbs on his car, and he used the Series 2 bonnet without scoops.

Any ideas?

Simon
 
https://www.flatdoguk.com/25mm-prop-shaft-spacer-kit~2153
Propshaft Spacer 15mm (Britpart) DA6339 Island 4x4 - Specialists in Land Rover and Range Rover Parts and accessories for all models. UK and worldwide mail order.

I fitted an 80mm electronic programmable speedo from here Smiths Instruments for International Cars
With a bit of tape wrapped round the body it was a snug fit in the stock circuit board. Made a small chopper wheel and fitted that to the stock SD1 speedo outlet and mounted a magic eye pickup on the box to read it. Simple to set up and looks good. You could also mount a pickup to read off the propshaft if space is tight at the speedo gear area.

No problem with height with my HS8 and bonnet. Maybe HS8 come in differing height Pots ? or maybe there is a lower manifold choice ? My HS8 came from a Jaguar.

I previously sent you pics of made up throttle linkage.

KEEP GOING !!!!!!!!!!!!!!!!!!!!!!!!!!!
 
Actual:

The gearbox and engine are in the car and the Rover on the hydraulic lift.
Some trouble occurred:

1.) the transmission tunnel is f****** narrow.
The LT77 touches the transmission tunnel, on the driver's side is only a few mm wide gap left.
I need to widen it with a hydraulic press to ensure enough space for movement of the drivetrain.
I used a club hammer and belted the offending bits out of the way.

2.) I can't fit the the speedo cable. Acutally the space is that narrow that i would have to make a hole in the tunnel for the cable. If i do so, it would bend very hard.
Is there a connector available to have it attached at a 90° angle?
There is a 90 degree adapter available.
3.) I need a distance-shim for the propshaft.
The autopropshaft fits, but i would feel better if i install a shim. I read anywhere they are available already. May i get a link to a offer?
Mine is bolted straight to the flange, and it never gave any trouble.
But the biggest problems of all so far.

The bonnet does not close with the HS8 carbs.
when the filler caps touch the bonnet, i would need 1,5 better 2 cm to close safely and provide space for engine movement.
I already invested a lot of time and effort in this solution so i don't want to give it up. I cant go back to HIF6, i needed parts of the linkage to try working on the HS8 and the manifold is ported now.
@RoverAlex used the same carbs on his car, and he used the Series 2 bonnet without scoops.

Any ideas?
Maybe you could space the back of the bonnet up at the hinges to get the required clearance?
Simon
 
Thanks, @cobraboy for the links to the prop shaft spacer.
The speedo looks nice, but it is not the way I want to go.

When I tried the 3.5 manifold on my new block and heads (i used a composite gasket to lower compression) I noticed it could "sit" a little lower.
But I managed to screw it down. Maybe this has more effect on the height than I thought.

To explain better I add a drawing.
When I installed the manifold I noticed that the "holes" (I don't know the right word) where the screws hold down the manifold to the heads are not "deep" enough to mount the manifold. If you look from the manifold down to the holes in the heads it looks like the picture A.
But it should look like picture B.
To lower the manifold I should mill the green coloured faces. Also, the inlet channels don't meet perfectly, so I could cure this problem either.
Is there a chance to damage the water jackets?
What do you guys think?

lowering_manifold.jpg

In your "4.6 get's green light" thread you wrote you measured the height of the HS8 compared to the HIF6.
Hey Barten
I have carefully measured the height of the dashpot caps up from the valley gasket on both engines and the HS8 are only about a 1/2" higher, so I think they will clear the uncut bonnet area anyway.
1/2" are 12,7mm which isn't that much. I guess I need about 15 - 20 mm lower to my actual height to close the bonnet safely and ensure some space for engine movement.
There must be something else wrong, I can't remember the original HIF6 setup to have that less space above.

it is also possible to use the choke. Not the full movement, but it wasn't needed to create "bowls" from thimbles like @cobraboy did.
space_under_jets.jpg

Also the throttle linkage has an angle upwards when connected to the manifold.
linkage_angle.jpg

You also wrote:
The inlet manifold I used seems to have a taller centre section than the HIF6 one, the tower height is the same, but the distance between the casting around the tower and the top of the tower is shorter, so looking through the opened up carb mount holes it looked quite big inside. I don't know what it came from.

I made some photos today in the workshop.
Tower height is approximately 85mm = 3,35"
tower_height.jpg

Height from the valve covers to the filler caps is approximately 200mm = 7,87"
height_valve_covers_filler_caps.jpg
I will write an email to Burlen regarding the height of the vacuum pots, but just from comparing my pictures with cobra's I think they are the same height.
Pot height is 95mm = 3,74"
pot_height.jpg

BTW, your pics from the throttle linkage helped me a lot. As you wrote, it has an effect on almost everything.

I really want to keep this layout with twin HS8, I also think the 4.8 really needs it, although I want to keep the revs down.
Going for a US-Carb and a pan like air filer is not really what I wanted.

Simon
 
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@unstable load
Thank's for your hints.

I used a club hammer and belted the offending bits out of the way.

I had a look at some pictures from other threads. Unfortunately Photobucket has some troubles showing the pictures.
I really need to save and download some of the pictures i need.
I will try with a hydraulic lift.

There is a 90 degree adapter available.
As i saw on some pictures the speedo cable isn't entering at 90°. It is swept forward.
I will lower the box when welding the mounts and have a look at that.
Do you have any idea where I could get those adapters?

Mine is bolted straight to the flange, and it never gave any trouble.
I measured today and I will order the 25mm spacer. @cobraboy also installed it as I read in one of his threads.
it works, but if the rear deflects, the movement is on its limit.

Maybe you could space the back of the bonnet up at the hinges to get the required clearance?
Thanks for that. I will have a look at this.

Simon
 
The angle of the horizontal throttle rod, the fact that you can't get the carbs to clear the bonnet, you are very tight in the tunnel, you need a prop spacer, would all make me think that the rear end of the gearbox is too high. When I did mine (in the small 3500S tunnel) I never had any of those problems, and I didn't have any problems with the speedo cable either.
 
Thanks, @cobraboy for the links to the prop shaft spacer.
The speedo looks nice, but it is not the way I want to go.

When I tried the 3.5 manifold on my new block and heads (i used a composite gasket to lower compression) I noticed it could "sit" a little lower.
But I managed to screw it down. Maybe this has more effect on the height than I thought.

To explain better I add a drawing.
When I installed the manifold I noticed that the "holes" (I don't know the right word) where the screws hold down the manifold to the heads are not "deep" enough to mount the manifold. If you look from the manifold down to the holes in the heads it looks like the picture A.
But it should look like picture B.
To lower the manifold I should mill the green coloured faces. Also, the inlet channels don't meet perfectly, so I could cure this problem either.
Is there a chance to damage the water jackets?
What do you guys think?

View attachment 12629
I worked out that the inlet manifold sat high on mine, looking at yours the inlet casting is high as the top of the inlet casting is up against the rocker cover, my bolts would not go in. I had skimmed my heads 0.040" to get 10.0 : 1 CR
I skimmed the green faces 0.030" on the inlet to line up the ports, you have to work this figure out on yours.


In your "4.6 get's green light" thread you wrote you measured the height of the HS8 compared to the HIF6.

1/2" are 12,7mm which isn't that much. I guess I need about 15 - 20 mm lower to my actual height to close the bonnet safely and ensure some space for engine movement.
There must be something else wrong, I can't remember the original HIF6 setup to have that less space above.

it is also possible to use the choke. Not the full movement, but it wasn't needed to create "bowls" from thimbles like @cobraboy did.
View attachment 12631
I gave up on the choke, I inject fuel into the inlet from the fuel return pipe using a fuel shut off solenoid.
Also the throttle linkage has an angle upwards when connected to the manifold.
View attachment 12634

You also wrote:


I made some photos today in the workshop.
Tower height is approximately 85mm = 3,35"
View attachment 12630
Mine is 50mm at that point, mine has a higher centre plenum.
Tower to top of pots is 123mm


Height from the valve covers to the filler caps is approximately 200mm = 7,87"
View attachment 12632
Mine is 170mm
I will write an email to Burlen regarding the height of the vacuum pots, but just from comparing my pictures with cobra's I think they are the same height.
Pot height is 95mm = 3,74
View attachment 12633
Mine is 95mm
I put a steel rule across the pots and out over the side of the engine. I measured down from the underside of the rule ( pot height ) past the exhaust manifold to the pinch weld that is near where the manifold goes 4 into 1. The height from the top of pots to the pinch weld is 487mm


BTW, your pics from the throttle linkage helped me a lot. As you wrote, it has an effect on almost everything.

I really want to keep this layout with twin HS8, I also think the 4.8 really needs it, although I want to keep the revs down.
Going for a US-Carb and a pan like air filer is not really what I wanted.

This winter I am going to try an Autolite 4100 4 barrel with Offenhauser intake :D

Simon
 
@harveyp6
Thanks, I have'nt thought about that!
The gearbox mount is not made yet, i just lift the whole engine/gearbox in and screwed a plate at the end of the gearbox to prevent it falling out. But that is too high, for sure.
I had a look and it needs to get lower.

The tunnel narrows in upwards direction, so you are right, there is more space available if the gearbox get's lower.
When I read through cobra's threads, I noticed he had measured the distance from the tunnel to the gearbox bottom to ensure the same height. I forgot to do that.
Maybe someone with a LT77 in his car could provide this information to me.

@cobraboy
... looking at yours the inlet casting is high as the top of the inlet casting is up against the rocker cover, my bolts would not go in. ...you have to work this figure out on yours.
So, skimming is the right word ;-)
That work is needed for sure. I will have a look on it. I managed to screw the bolts, but... yes... it was a tight fit.
0,030" is not much, even in case i need to skimm more, it would gain a few mm in heigth. But in combination with lowering the gearbox...

I gave up on the choke, I inject fuel into the inlet from the fuel return pipe using a fuel shut off solenoid.
I read this a few times in you thread, but I don't really understand how you realized it. Is it just a few drops of fuel "dripping" into the inlet or a sort of nozzle "spraying" it in.

Mine is 50mm at that point, mine has a higher centre plenum.
I had a closer look at your pics in the "HS8"-Thread. I see the difference. I have not measured between the distance tower-top of pots.
HS8

I found a picture of a 3500S NADA with the same manifold
LanceLaCerte-EC.jpg


Height from the valve covers to the filler caps ... Mine is 170mm
That number would make no problem for me. But 30mm difference isn't that less. :confused:

I put a steel rule across the pots and out over the side of the engine. I measured down from the underside of the rule ( pot height ) past the exhaust manifold to the pinch weld that is near where the manifold goes 4 into 1. The height from the top of pots to the pinch weld is 487mm
I have to figure out that, car is around 500km away from me now, but I will visit the old lady on tuesday next week ;)

This winter I am going to try an Autolite 4100 4 barrel with Offenhauser intake :D
I could interpret you would like to offer me your "special" manifold which proved to work :p:D:D:D

As i wrote in a earlier post, it is not just because of the US-carb, it is because of the looks. If - to the untrained (uniformed ;)) eye - it looks like twin SU and a snorkel in between as on every rover that's exactly what i wan't to achieve :p

Simon

PS: I found another 4.6 with HS8 carbs. Not a P6, but a Rover: Chris Cowdery Global Presence
 
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I found some more information on the manifolds.
BTW: RoverAlex used the same manifold as I did in his P6 race car.
Here you can clearly see the difference in tower heights:
10105965846_f094edb090.jpg
10106006703_b0ee6c8581.jpg

Source is a thread in the V8 forum: Machining a Rover V8 Inlet Manifold for a Holley 390 - The V8 Owners Forum -

A user called harvey wrote:
I think your right about the dirty one being SD1, but the other one is early P5B/P6B (HS6 carbs) because it has the blanking plug on the front of the tower which is where the AED was fitted.

Seem's to be right: Classic Rover P5B V8 3.5litre Inlet Manifold | eBay
But this particular one in the offer has quite a thick layer of remanufactureness :D
 
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Regarding the choke.
The HS8 have large brass stubs on the top where the old AED pipes attached, I made jets to go in these stubs and squirt fuel in from the fuel return pipe, the fuel is controlled by a fuel cut off solenoid and a small switch on the dashboard. A small amount of fuel will start the car but I have to keep the car running with the throttle pedal as there is no fast idle cam on the carbs.
IMG_0669 (1).JPG IMG_1391.JPG
The two fuel pipes at the top come off the brass stubs which have reducing jets in them, join at a T piece, then head off to a fuel cut off valve on the inner wing. A pipe from the feed side of the cut off valve Tee's into the return pipe to the tank.
I could not get the original method of lowering the jets to start the car to work, the jets need to be lowered a lot to provide the necessary enrichment and the rocker cover was in the way.
Sorry the interpretation of a 'sale' of this set up is not accurate at this time, I have to make up the 4 barrel set up and go back to the rolling road to see if it is any better.
At least we now know what manifold this is, so now you can obtain one. However if you do you will then have all the problems I had with the main jets not clearing the rocker covers.

Remember - if it was easy they'd all be doing it ;)

Checking your gearbox mounting height as Harvey says will maybe prove worthwhile.
 
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Thanks for taking the photos.
Now I understand.
Amazing solution.
Don't you use some pressure (pump) to inject the fuel, or is it working because of the sucktion?
Have you thought of constantly keeping a small fuel flow into to carbs via your jets to sort of enrich the mixture?

BTW, i found a sandblasted inlet manifold (same as your's) in south germany via internet. The offer is almost 1,5 years old but it's still for sale.
Price is okay, so let's give both measures (lowering gearbox, new manifold) a try.
 
The fuel in the return pipe is under pressure from the main fuel pump as the return pipe has a restrictor in it at the tank end. All I have to do is open the fuel cut off valve and fuel is squirted under pressure into the carb runner.

I used the smallest drill I had for the size in the jet, I cannot remember what is was, it was around 20 - 25 thou. There is no need to permanently enrich the motor if the carb jetting is right. Anyway its far too much to put in that way.
BTW why do you want to keep the revs down ? A 4.6 wailing above 5000 rpm in a P6 is just the dogs bo**ocks !!!
 
Hi, You could use a 0.6 MIG tip which is 25 thou, (more or less for Harvey's sensibilities).

Colin
 
It was maybe a little less.
You wrote:
I made some brass jets to fit in the AED stubs on the carbs, they need to be around 0.010" - 0.015" holes to work good.
in a earlier thread HS8 Choke Question

This is the desired object:
$_57.JPG


I had a look at my carbs, only one of my carbs has a similar connection. But no problem to drill and insert a jet there.

With keeping the revs down I meant the torqe curve should be in the lower/middle rev range, because that's my way of driving.
I like the idea of taking small roundabouts or turns on twisty alpine roads in third and having this smooth, effortless "build up" of speed that a natural aspirated big capacity V8 delivers (served with delicious sound).
I do not plan to restrict the ability to rev by any measures, if it pulls nicely up to 6000, ... let's grab the dog's bo**ocks :D ... (hm... if i got that phrase right?)

Isn't the redline beginning at 5000?

I could not find a satisfying answer about the Piper270 camshaft which came with the block. Piper announces it as a "fast road cam" on their website Camshaft From Piper Cams
Some customers in other forums wrote this is more a "smooth idle" cam and the rev range is rather low for a road cam.

As I wrote earlier it was not a specific choosen engine, it was sort of using the components that were available.
To be honest, I am really a little worried about the brute torque this 4.8l could deliver if I let it... o_O

BTW, it's allways great to learn new things :rolleyes:
'Dog's bollocks' - the meaning and origin of this phrase
 
I did say I could not remember the size, anyway what's 10 thou between friends.
Thanks Colin for inputting Harvey's sensibilities, first time I knew he was sensible.

Tyrol
If you hang about long enough we can teach you much more about bollocks.

Cannot post any more, have to keep an eye on the amount of red wine going into the bolognaise.
 
I could not find a satisfying answer about the Piper270 camshaft which came with the block. Piper announces it as a "fast road cam" on their website Camshaft From Piper Cams
Some customers in other forums wrote this is more a "smooth idle" cam and the rev range is rather low for a road cam.

Hi, The capacity changes the 'wildness' of a cam. I learnt from my youth with Ford Kent engines that what is fast road in a 1500cc becomes full race in 1000cc. So it depends what Piper's recommended engine size the cam is for. A phone call to them may clarify.

Colin
 
Thanks, i will have a call there.

BTW:

If i want to use a Oil cooler on the P6 like this one:
V8 Oil Cooler Kit - RB7260 | Rimmer Bros
90873-Large.jpg

The space for the oil filter is even less than now.
If i get it right this would require a remote oil filter too.
Is it possible to combine both adapters?

or should I use a new oil pump cover (like this for the mgb gt v8)
Oil Pump Cover With Take Off - BHH998 | Rimmer Bros

I am a little confused. https://www.v8tuner.co.uk/product.php?id=147

This kits are either for a remote oil filter or a cooler. But how is it possible to combine this, or is it not needed?

Simon
 
4.6 gets the green light !
Post #25 page 2.
Worked for me, I would not go less than 19 rows on the cooler. You must use a thermostat somewhere, either as a sandwich plate or inline. BTW I have an SD1 front cover, the filter thread is smaller than the P6 at 3/4 " x 16 TPI.
Think Automotive should be able to supply a threaded adaptor to work with the P6 thread or you may already have moved to an SD1 front cover ?
 
I knew I read about someone installing a oilcooler but i couldn't find the thread yesterday.
Know I remember it was you.
I have used the P6 Front cover.
 
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