Top end rebuild

SydneyRoverP6B said:
Hello Stan,



It is my understanding that a new camshaft can be all too easily ruined if the engine does not fire within the first few turns,..as the camshaft prelube will be wiped off and the lobes will then begin to scuff.



Ron.
Click to expand...

This leaves me at a bit of a loss :? I have rebuilt many engines over the years and have never struck problems of this nature, surely if the this is a problem why not coat the moving / wearing parts with Moly Paste? not moly grease but paste (60 to 70% molybdenum disulphide solids) this will remove any possibility of galling for quite some time.

Graeme
 
Hi Graeme,

As far as I know proprietary cam lubes do contain moly disulphide, but I'm sure a straight paste like you suggest would also work OK. I know Harvey swears by Graphogen (Colloidal Graphite paste) and is recommended by people such as Burton.

I've smothered my camshaft and lifters with Kent Cam Lube, but I may well get some Graphogen on the lobes as well before I fit the inlet manifold.

What have you used when building up engines?
 
Hello Graeme,

I have attached two links from Piper Cams along with Crane Cams covering their camshaft running in procedures. This information applicable for any camshaft that may be fitted to a Rover V8.

In my mind, when minimal cranking is recommended, that to me suggests no more than say 6 turns of the crankshaft, which is 12 turns of the camshaft. I also recall reading an article which stated that cranking over more than the aforementioned number of turns can result in the new camshaft being ruined, even if moly paste is used as is covered in the Crane Cams article.

http://www.v8engines.com/Acrobat/cam-installation.PDF

http://cranecams.com/pdf/214e.pdf

Ron.
 
SU HIF6 jet height...

OK..needle valves sorted and floats set. Depending on which tuning manual you read, the jet should be levelled with the bridge then the mixture screw richened up by 2 or 3 full turns, which puts the jet 8 to 12 thou below the bridge. Des Hammil's book recommends a starting point for 1.3/4" carbs at 50 thou below to ensure starting. Basic Startup Settings

What are people's view on this? Is this assuming you don't use the choke on initial startup?
 
Hi Stan,

When I rebuilt my SU carbs and refitted them to my original 3.5 only days before the engine came out to make way for the 4.6, I set the jet heights to approx 1.5mm below the top of the bridge. This is a tad more than Des Hammill recommends, but I did it largely by inspection, and the engine started straight away after filling the float bowls via the electronic fuel pump.

The chock must be used in order to start the engine, when cold at the maximum setting.

Ron.
 
SydneyRoverP6B said:
In my mind, when minimal cranking is recommended, that to me suggests no more than say 6 turns of the crankshaft, which is 12 turns of the camshaft.
Ron.
Click to expand...

Camshafts run at HALF crankshaft speed not DOUBLE, so for 6 crank rotations, the camshaft will only turn 3 times.
 
Hello Harvey,

Ooops,...thanks for correcting me. I never mind admitting when I am wrong, had been a long day, and I was very tired....yes indeed, 6 crankshaft rotations equates to 3 camshaft rotations.

The 6 crankshaft rotations remains the objective not to exceed.

Ron.
 
SydneyRoverP6B said:
Hello Graeme,

I have attached two links from Piper Cams along with Crane Cams covering their camshaft running in procedures. This information applicable for any camshaft that may be fitted to a Rover V8.

In my mind, when minimal cranking is recommended, that to me suggests no more than say 6 turns of the crankshaft, which is 12 turns of the camshaft. I also recall reading an article which stated that cranking over more than the aforementioned number of turns can result in the new camshaft being ruined, even if moly paste is used as is covered in the Crane Cams article.

http://www.v8engines.com/Acrobat/cam-installation.PDF

http://cranecams.com/pdf/214e.pdf

Ron.
Click to expand...

Oh well if they say so who am I to dispute it, though as was mentioned in one that the removal of zinc in recent years will make a significant difference. Thanks for those links which I have now read and saved to my Rover file. :D

Graeme
 
arthuy said:
Stan

last week I started the engine for the first time since I did the top end rebuild, sounds awesome but I only ran it for a few seconds whilst setting up the distributor.

Colin
Click to expand...

Hi Colin,

Do you have a mechanical fuel pump on your P5B? And HIF carbs by any chance? Just wondering if & how you primed the fuel system before your first start up.

=================================================================================================

Anyway, carbs sorted & replacement inlet manifold built up...getting there slowly! :)



 
The only way I could see would be to disconnect the pump from the timing cover and waggle the lever for a bit to push fuel through the float bowls.

When I rebuilt my AC pump a few weeks ago though the car started the same as normal so maybe it doesn't take long for the petrol to flow through?
 
You talking about the mechanical pump on the engine? Is the v8 one not like the ones on the 4 pots, these have little levers under the body allowing you to prim it without needing to turn the engine over.
 
The AC mechanical pump has no built in provision to move fuel in order to fill the float bowls without running the engine.

In the case when the carburettors have been rebuilt and the float bowls are empty, filling them before hand without waiting for the pump to supply is most necessary. Each carburettor has a vent pipe coming off each float bowl, both for expelling vapours and for discharging fuel onto the road in the case of float failure.

By pouring fuel directly using a suitable piece of hose or tiny funnel into each float bowl chamber via the brass vent pipe, the bowl will be filled. Any excess fuel will overflow, but once the engine starts the level will immediately fall as the fuel is drawn in and in such time the AC mechanical pump will be supplying a fresh supply.

Ron.
 
Thanks Ron...now I know there's a tiny funnel lurking somewhere in the house...

If not..it's on the list for Wilko's. :)

Cheers,
 
Well..in between Easter visiting & looking after my gorgeous granddaughter....



....not managed to make a lot of progress!

Inlet manifold's on though...





Got to sort the throttle countershaft & coupling rod out...can't see Halfrauds having tiny split pins...never know though! :D

 
Hi all,

What should the bolted-up clearance be between the oil pump gears and the cover? Haynes talks about .0018" to .0058" between the gears and the cover, and with a .006" gasket (uncompressed) this gives a final clearance of .0002" to .0042".

Sound about right, do you reckon?
 
Hmm...wasn't happy with this 2 tenths of a thou figure...bit of heat and differential expansion, slight contamination in the oil...before you know it the gears'll pick up on the cover and I'll have lost a tooth or three on the cam/dizzy gear. So I nipped to the local LR dealer at lunchtime and bought an OEM gasket for the grand sum of 56p. Which mics up at .012"...twice the thickness of the one in the upgrade kit!

So the .0002" to .0042" would become .0062" to .0102", or more likely .003" to .007" after the gasket compresses!

I'm happier with this, I know wear will increase it over time, but the taller gears with this sort of end float will still deliver much better volume than the the P6 gears. So the spacer plate's now licked up on the surface grinder, burrs stoned off the gears, and all bolted up. Feels right at about 4 to 5 thou. :)
 
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