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Crank / Cam Housing Bore Diameters

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Old 07-30-2016, 03:21 PM
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Default Crank / Cam Housing Bore Diameters

I'm considering having a local engine machine shop work on my 4.6L. They have a Rottler machine, but mostly work on American engines. Does anyone know what the crankshaft and camshaft housing bores are for the 4.6L?

A big part of the pricing will be based upon whether or not they can fit my block into their Rottler using adapters they already have in the bin versus having to make adapters for the Rover.

Also wondering if the specs from the Buick V8 would be the same? Looking for the true engine pros on this forum.... who can step up?

 
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Old 07-31-2016, 10:31 AM
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So, I found this discussion from August of last year about Connecting Rod Big End Bore Size:

https://landroverforums.com/forum/di...re-size-75200/

Thanks to a lot of user input, searching and what seems to be reliable data ultimately delivered from Turner Engineering the specification for Connecting Rods seems to be 2.313 +/- .0005. This is the big end bore measurement (and tolerance), obviously without the bearing shells installed.

What we don't seem to know is:

Camshaft Housing Bore Size = ?
Main (Crankshaft) Housing Bore Size = ?

Any machine shop that plans to bore or align hone a block needs these Main and Cam housing dimensions in order to fit the block into the machinery.

It blows my mind that these figures don't seem to be published anywhere.
 
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Old 07-31-2016, 12:56 PM
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This is it for the crankshaft - yes? Pulled from the overhaul manual. The only data on camshaft is the end float and max run-out.

What's the best tool to use to measure this ourselves? Trying to limit shop work... since I have no reason to believe anything is wrong with my block.

 
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Old 07-31-2016, 04:22 PM
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If you look again at the link the 2.313 (58.75mm) is 'Connecting Rod Housing Bore size' according to Turner Engineering. I have taken some measurements from my 4.6L con rods + bearing shells and I agree with this figure.

More Information: This is the size of the circular opening of the big end of the connecting rod with the bearing cap installed, but without the bearing shells installed. The reason someone would need to know this, primarily, is to check for an out-of-round or 'ovality' condition on the con rod big ends. If found to be slightly out of round they can be machined and fitted with non-std bearings, or if really damaged they would need replacement.

Now, what my machine shop needs is:

1. The size of the circular opening of the camshaft journals without a cam bearing installed. This is Camshaft Housing Bore Diameter.
2. The size of the circular opening of the crankshaft journals with the main bearing cap installed but without the main bearing shells installed. This is Crankshaft Housing Bore Diameter.

This is critical data for fitting the block to the Rottler machine in order to align bore the block to accept Darton top hat sleeves.

I have done some minimally scientific calculations to arrive at the measurements and this is what I have come up with:

NON-OFFICIAL - Camshaft Housing Bore Diameter = 1.895" (48.14mm)
NON-OFFICIAL - Crankshaft Housing Bore Diameter = 2.635" (66.93mm)

DISCLAIMER - I am not an engineer, and this is no place for guesswork. The above figures, while probably close, need to be authenticated and trued-up by a reliable source.

 
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Old 07-31-2016, 04:32 PM
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No idea then - but I'm subscribed to this thread as I'll probably need the same data. Weird that the overhaul manual wouldn't have it.
 
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Old 07-31-2016, 04:36 PM
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Even more weird that the machine shop wouldn't have any reference for it. And these guys are big-time - you should see some of the engines they are working on in that place. Looks like some amped-up version of an Engine Power TV episode. No joke.
 
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Old 07-31-2016, 06:14 PM
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Now, what my machine shop needs is:

1. The size of the circular opening of the camshaft journals without a cam bearing installed. This is Camshaft Housing Bore Diameter.
2. The size of the circular opening of the crankshaft journals with the main bearing cap installed but without the main bearing shells installed. This is Crankshaft Housing Bore Diameter.

This is critical data for fitting the block to the Rottler machine in order to align bore the block to accept Darton top hat sleeves.
Those dimensions would usually only be found on engineering drawings for the block since not needed for normal maintenance or overhaul. Have you reached out to any of the other known RV8 rebuilders? Anecdotal reports by some who have taken the measurements may be out there if you search enough.
......
 
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Old 07-31-2016, 06:48 PM
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Originally Posted by number9
Those dimensions would usually only be found on engineering drawings for the block since not needed for normal maintenance or overhaul. Have you reached out to any of the other known RV8 rebuilders? Anecdotal reports by some who have taken the measurements may be out there if you search enough.
......
Sure, I just don't want to be the d-bag calling Vance at Q&E for the information so I can bring my block to another machine shop here in Pennsylvania to have the work done. Seems like a cheesy thing to do, but he might be the type of guy to cooperate for the sake of the community. Don't know.

Maybe someone over at RPi would be willing to divulge this data? Considering their experience with the coscast blocks I would think they have to know.
 

Last edited by Fast951; 07-31-2016 at 06:55 PM.
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Old 08-03-2016, 08:29 AM
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Update from Turner Engineering (Richard Turner):

'The main bearing housing size is 2.666” -.0005”. We do not have specific dimensions for Rover V8 cam bearings. The bearings we use and sell are pre finished and it can be reasonably assumed that the fitted bore size of an original land rover V8 cam bearing bore will have a clearance in the region of .0015” to .0025” over that of the camshaft journal diameters.'

I have measured an original Land Rover V8 camshaft bearing at 1.914". Subtracting .0020" gives a final measurement of 1.912" (48.56mm).

So, with some authority this time:

Main Bearing Housing Bore Diameter = 2.666" (67.71mm)
Cam Bearing Housing Bore Diameter = 1.912" (48.56mm)

 
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