Need help finding a rover torque plate to machine block

Started by 74MGBV8, February 01, 2014, 03:51:56 PM

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74MGBV8

Anybody out there know where I can rent a torque plate for a Rover 4.6 engine. I have contacted several machines shops in the Dallas, TX area and no one has one to machine my block. I don't want to spend several hundred dollars buying a new plate when it s going to be used once. Any leads would be greatly appreciated.


DiDueColpi

Dan,
I'm sure that this will initiate a hornets nest of controversy, but don't bother with a torque plate on the Rover block.

For several reasons.

# 1 is, look at your current bore. It's likely worn evenly with no high spots or signs of excess wear near the head bolt areas.
The factory did not use torque plates and the bores don't seem to distort under the stress of head torquing.

Which brings us to reason # 2, the steel liners tend to float in the block. Basically they are clamped between the head gasket and the relief at the bottom of the block.  That insulates them largely from the distortions that the aluminum block would impart upon them if there was a more solid mechanical connection.

# 3 is the fact that each time that the block is torqued is a unique situation. Meaning that the distortion imparted to the cylinder bores is not repeatable.

Lastly, no torque plate can replicate the clamping loads of the cylinder head, on the cylinder block, when it is at operating temp, under load.
My rule of thumb is to examine the worn cylinder bores closely.
An even wear pattern clearly indicates no bore distortion issues, and therefore no need for the use of a torque plate.
If the need for one is indicated, then to be useful, it's design needs to replicate the clamping loads of the head as nearly as possible.
Otherwise all of your effort is wasted. A flat steel plate bolted to the block just won't do it.

Cheers
Fred

tr8todd

I respectfully disagree.  Seen way too many engines built without a torque plate that have excessive blowby, and after tear down find out of round and tapered bores.  Not seen that issue even once since I started using a torque plate.  My machinist in RI made one up after I borrowed one on a stroker build.  Technically it's his, but I can see if it's available to loan out.  Tim Lanocha has a couple as well.  It may not be the be all end well, but it's better than machining the bores without one.  Most of the engines people are rebuilding now are pushing way more power they left the factory with.  If you are just going with a fairly standard rebuild, I'll agree that a torque plate probably isn't worth all that much to worry about.

DiDueColpi

The intent of a torque plate is to replicate the distortions imparted to the cylinder bores by a fully assembled engine.
This seemingly simple task is actually very hard to accomplish correctly.
Some engines respond well and some show no improvement.
The power level of the engine really has no bearing on the use of the torque plate.
The structure of the block dictates its usefulness.
Engines like the small block chevy with open bottom bolt holes and head bolts placed very close to the bores.
Will distort the bore significantly when the head is bolted down.
These engines respond well to a properly done torque plate.
In my experience the rover block doesn't distort the bore very much, if at all.
If the plate is working for you. Then by all means keep using it.
For me though, it hasn't proved necessary.
Cheers
Fred

roverman

Gentlemen, Let's complete the scenario ? Coscast block ? Re-sleeved ? Likely a near 3.5" bore, 215 block with intregral cast liners will distort minimally. Most folks using a deck plate, suggest torking an identicle gasket in place, to the final one. Using studs ? Compensate the torque readings for 7/16-20 threads ? Studs will load/distort the bores differantly, than bolts. IMHO, I like to err on the cautious side.  I have (1), to "possibly" donate to BV8. Potential rental income, to the site we cherish-Curtis ? Cheers, roverman.

quietone

I will have one for the 3.736 bore in the near future, but it is not done yet. Also helps to torque the mains before boring and honing.