Engine rebuild

[911Dreamer]

My dad's 500 Chimaera is in the process of having a new clutch. The mechanic is also fixing some oil leaks, and has found metallic debrit in the sump - suspected big end bearings. As the car also has a noisy cam, the mechanic basically says that my dad would be looking at an engine rebuild. Is this good advice and also, roughly how costly would that be?

Cheers.

911Dreamer

[pullingpower]

Suggest contact V8 developments. Generally regarded as the Don's in this area and they know how to build a good engine. Should be able to give you some good professional advice if nothing else. Contact details are on this site somewhere. They did my engine rebuild by the way and did a great job.

[tyre_tread]

pullingpower said:

Suggest contact V8 developments. Generally regarded as the Don's in this area and they know how to build a good engine. Should be able to give you some good professional advice if nothing else. Contact details are on this site somewhere. They did my engine rebuild by the way and did a great job.

I have just ordered a rebuilt 4.0 Chim engine for my Rover P5B. I did quite a lot of reserach before I plumped for V8 developments.

Call Ray Webb or Bob on 01775 750000. They're based in Spalding.

[Tobs]

Before jumping to 'it needs a rebuild conclusion'. Are you sure the 'metallic debris' are not part(s) of a rocker pad that has dropped off a rocker (seems to be quite a common occurrence)? (Could also be the reason of thinking it needs a new cam due to the tapping it would make!)

[tyre_tread]

Tobs said:

Before jumping to 'it needs a rebuild conclusion'. Are you sure the 'metallic debris' are not part(s) of a rocker pad that has dropped off a rocker (seems to be quite a common occurrence)? (Could also be the reason of thinking it needs a new cam due to the tapping it would make!)

I was going down the new cam route until I read David Hardcastle's book "The Rover V8 engine". Whilst it concentrates mainly on the history of the cars into which the RV8 was installed, it also look at some of the development work and some of the common fallacies, misconceptions about the engine and weak spots.

There is a tendency for the rocker shafts and arms to wer due to the oilways in the rocker shafts becoming blocked. The particles that wear off then circulate in the oil and embed themselves in the soft metal of the crankshaft bearings thus shortening the useful life of the bottom end. This can, of course, mean it will still last for years if you do relatively few miles and are lucky and the engine is not highly stressed.

There is some excellent information on the RPI website : www.rpiv8.com/engine.htm - having said that, after talking to them I felt that a lot of their discussion/info was steering me towards butying a nice shiny new engine at twice what I paid for V8 Developments to build one for me.

The only effective way to tell if the engine needs a rebuild is to inspect it. That, of course, would mean stripping it to a degree to look at the top end. If the rocker shafts are worn (you'll have to take a rocker arm ot two off to tell for sure, then the likelihood is you should rebuild.

RV8's also have a tendency to starve no 7 & 8 cylinders of oil and wear the cam lobes. This COULD explain the tapping. However, an exhaust manifold that is leaking also can do a good impression of a noisy tappet. It sounds bizarre and I didn't believe it until I had a tappety noise on my P5B some time ago and someone told me about this. I xhecked the Exhaust manifold bolts and lo and behold I had 2 loose. Tightened them up and all went quiet! Worth checking!

[911Dreamer]

Tobs said:

Before jumping to 'it needs a rebuild conclusion'. Are you sure the 'metallic debris' are not part(s) of a rocker pad that has dropped off a rocker (seems to be quite a common occurrence)? (Could also be the reason of thinking it needs a new cam due to the tapping it would make!)

That is very interesting!

Is there anyway (easy way) to prove / disprove this theory?

Cheers
911Dr

[900T-R]

In all fairness, by the time the engine is out and stripped to a degree that one can actually see for themselves what's what, it makes no financial sense not to rebuild the thing.

[that daddy]

pull the rocker shafts off and inspect the pads,the debri in the sump is probably the remains of a shagged cam lobes & followers,try picking up the bits with a magnet,if they dont stick to the magnetic pen its bad news and probably is bearing material,why not get the mechanic to drop the con rod caps and inspect the bearings 1st,got to be worth a try possibly saving you a bundle

[tyre_tread]

anonymous said:

[redacted]

Very cool thinking.

Wasn't really the plan, just that the engine he had to be rebuilt was out of a Chim.

I'll now have 2 chim engines and only one of them in a Chim!

[coetzeeh]

When I replaced my cam shafts at 36k miles the rocker pads had partially disintegrated.

Shudder to think where those bits are, but 10k miles later my engine is still good (touching timber).

A number of fellow RV8 TVR owners suffered exactly the same problem with the rocker pads...

[spend]

Dropping the sump enables a visual inspection of the bottom end ~ pretty quick & unobtrusive, just like the rockers. Just need a bit of sealant for the plenum & sump re-assembly (depending on the state/type of rocker gaskets).

Dave

[CHEF_GOLF]

hi had mine rebuilt at v8 developments they are very good, you need to see their set up. its now a perfect time to get all those engine upgrade goodies

[jonathant]

tyre_tread said:

RV8's also have a tendency to starve no 7 & 8 cylinders of oil and wear the cam lobes.

OOI what is the reasoning for this, poor design?