Knocking RV8

kstrutt1 · Post by **kstrutt1** » Wed Feb 13, 2008 9:06 am

I am looking for some advice from those more experinced in the RV8 than I am. I have more or less finished installing a RV8 in my TR7, it is basicallly a standard carbed SD1 unit. I purchased the engine second hand and partilly stripped it before installation, I thought I had struck gold as it was very clean inside and virtuallly everthing looked like new (it is also painted the blue which is usually used by re-conditioners), I didn't remove the crank or pistons but did check a couple of bearings.

I now have it all back together and on on start up it sounds great, the problem is when it gets hot, after a long idle where it has beeen cycling on the electric cooling fan (90deg C cut in) a heavy knocking starts, it can be stopped by pulling the plug lead off on cyl 2 on the LH side and it goes away when the engine speed is raised above idle. I have also removed the sump and checked the big ends which look fine, removing the plug lead on the other cylinder which shares the crank journal has no effect.
My thoughts are it must be a piston / con rod issue possibly the piston is upside down or damaged, my plan is to finish the rest of the installation (mainly modifying the bonnet to clear the carbs), fit an oil pressure gauge and drive it to see if the issue is evident under load.

Has anyone any other ideas / thoughts?

Kevin

Post by **katanaman** » Wed Feb 13, 2008 9:45 am

what grade oil are you using and what is your oil pressure? If your not using 20/50 then change it.

kstrutt1 · Post by **kstrutt1** » Wed Feb 13, 2008 10:50 am

It currently has 15w40 in it, I have used this on all my older engines with no problems before, but if 20/50 is worth a try I will give it a go.
I haven't been able to connect the oil pressure gauge yet as I am awaiting an adaptor, hopefully it will be here tomorrow.

Kevin

ian.stewart · Post by **ian.stewart** » Wed Feb 13, 2008 11:26 am

Pre serp engines do not like anything less than Real 20/50.
You say when you take no2 lead off the plug the knocking goes away, I wonder if you have a plug or lead breaking down whan hot.

chodjinn · Post by **chodjinn** » Wed Feb 13, 2008 12:49 pm

This may sound like a wierd request, but can you post a pic of the block?

The reason is I would like to know if the blue colour you are talking about is 'Lund Blue' . . .

I hope for your sake it isn't lol

kiwicar · Post by **kiwicar** » Wed Feb 13, 2008 1:00 pm

20/50 oil and Lund engines in one post.... is this a record!!!

Mike

chodjinn · Post by **chodjinn** » Wed Feb 13, 2008 1:33 pm

kstrutt1 · Post by **kstrutt1** » Wed Feb 13, 2008 3:58 pm

I will try to take a picture tonight, there is't much of it left though as I cleaned most of it off. It was a dark blue which covered heads, block, front cover and sump.

Iv'e got to ask the obvious, what is the significance of Lund Blue.....

Kevin s

chodjinn · Post by **chodjinn** » Wed Feb 13, 2008 4:52 pm

You might eb alright actually, as the 'Lund Blue' is a light blue (quite distinctive).

Without opening a massive can of worms or typing for hours, Lund was an engine builder way down south, who went out of business a yr or so ago. He is (or was to be more accurate), by some reports possibly one of the best Rover V8 engine builders in the country - if you got him on a good day. Myself, Badger and others, however, seemed to have had their engines built on a 'bad' day. On those bad days, some would argue, a trained chimp would have done a better job

That mistake cost me £2.5k.

He was known for spraying blocks/heads/rockers in a particular blue colour so you knew it had been built by him.

kstrutt1 · Post by **kstrutt1** » Thu Feb 14, 2008 11:11 am

I had a look last night but the only bits of paint left are buried behind the FEAD, it was a very dark blue commonly used by engine rebuilders around here in Essex. I did find one error when I took it appart which was a wrongly assembled rocker shaft, so it obviously was not the best quality re-build in the world, on the other hand it doesn't smoke and runs very smoothly until it gets hot, For piece of mind if nothing else I think i will pull the sump and head off and remove the piston for a thorough check before any damage is done to the bore.

Kevin s

chodjinn · Post by **chodjinn** » Thu Feb 14, 2008 12:25 pm

a wise precaution!

jefferybond · Post by **jefferybond** » Tue Feb 19, 2008 1:40 pm

Maybe it's a blowing exhaust gasket on one cylinder (the one you pulled the plug lead off)? Sometimes exhaust leaks can sound like a tapping/knocking.

Jeff