First time rebuild - big picture heavy.

AntC · Post by **AntC** » Tue Sep 15, 2015 10:41 am

I'm back! With lots of shiny reconditioned and new parts and an empty wallet!

First job is to replace the piston rings with new ones. I haven't made a start yet because I have only just googled how to check the piston ring gap.

I am rather dreading this as I would not feel to comfortable filing the end of a ring to get the correct gap. Any hints anyone can give?

SimpleSimon · Post by **SimpleSimon** » Tue Sep 15, 2015 10:54 am

AntC wrote:I'm back! With lots of shiny reconditioned and new parts and an empty wallet!

First job is to replace the piston rings with new ones. I haven't made a start yet because I have only just googled how to check the piston ring gap.

I am rather dreading this as I would not feel to comfortable filing the end of a ring to get the correct gap. Any hints anyone can give?

I doubt you will be needing to file fit standard size piston rings on used bores

AntC · Post by **AntC** » Tue Sep 15, 2015 11:52 am

You are right. It was just something in the manual that scared me a bit, as you say, quite needlessly.

However, getting the lower rings in place is a bit tricky. By that I mean the thin rings.

SimpleSimon · Post by **SimpleSimon** » Tue Sep 15, 2015 12:07 pm

AntC wrote:You are right. It was just something in the manual that scared me a bit, as you say, quite needlessly.

However, getting the lower rings in place is a bit tricky. By that I mean the thin rings.

If you mean the thin oil control ring (2 on each piston) that secures the serrated insert they are easy just wind them down the piston they are not brittle so no fear or breaking them just dont bend em, also make sure that the serrated ring does not get over lapped at its ends while your in the process

AntC · Post by **AntC** » Tue Sep 15, 2015 12:33 pm

Thanks for the advice - I am a bit scared of breaking them!

The top two rings came in two conjoined plastic bags and both sets of rings look identical. Is there a difference? I thought one ring was supposed to be chromed, but that's not the case here.

AntC · Post by **AntC** » Tue Sep 15, 2015 6:53 pm

Why are there these red and green bits on this ring insert?

Should I prize them off after fitting?

AntC · Post by **AntC** » Wed Sep 16, 2015 4:28 pm

The coloured fittings are to show where the join is in the insert so that you can align the rings accordingly around the piston, and they do not come off.

Never seen anything like that before.

AntC · Post by **AntC** » Thu Sep 17, 2015 5:50 pm

seem to be talking to myself here.

Can someone tell me what thread the bolts are that hold the engine mounts on? I need longer ones and it's a fairly coarse thread and there are two on each side.

Thanks

DaveEFI · Post by **DaveEFI** » Fri Sep 18, 2015 8:37 am

Pretty well all the threads into ally on the RV8 are UNC. If you measure the thread diameter and Google thread dimensions for UNC, you'll get the size.

AntC · Post by **AntC** » Fri Sep 18, 2015 8:40 am

DaveEFI wrote:Pretty well all the threads into ally on the RV8 are UNC. If you measure the thread diameter and Google thread dimensions for UNC, you'll get the size.

Thanks Dave - I thought that might be the answer, but just wanted to check. I used to have a thread measurer, but can I find it?

DaveEFI · Post by **DaveEFI** » Fri Sep 18, 2015 10:15 am

AntC wrote:
DaveEFI wrote:Pretty well all the threads into ally on the RV8 are UNC. If you measure the thread diameter and Google thread dimensions for UNC, you'll get the size.
Thanks Dave - I thought that might be the answer, but just wanted to check. I used to have a thread measurer, but can I find it?

Other way if you have a bolt or nut is to measure the head across the flats (AF) in inches. Ie, 5/16ths or whatever, or take it from an AF spanner. You'll find tables which give you the thread size from that. Although there is the odd bolt with the 'wrong' sized head for special use. But not in this case, IIRC.

AntC · Post by **AntC** » Thu Oct 01, 2015 2:12 pm

The new 3.9 camshaft is like this - all the lobes seem to be covered in a black paint (?). Should this be removed?

Also, the orange paint on the end, does this have a significance?

bigaldart · Post by **bigaldart** » Thu Oct 01, 2015 3:09 pm

Hi,

The camshaft coating helps with break in and should not be removed, just clean the bearing surfaces if there is any residue on there, sometimes they use a greasy preservative, a pit of petrol as a solvent usually gets rid of it. Use plenty of clean oil on the journals when installing in the block. The orange paint will just be for the manufacturer and stockists to identify the cam quickly. There is no need to remove it. Make sure you use a good assembly lube on the can and followers, Crane is very good, if you can get it the old assembly paste that came in a black pot is excellent, the current red liquid that comes in a bottle works just as well though, I also use this on the mains and big ends together with piston pins if they are fully floating. It clings well and as we often have the engine sat for a month or two before running it gives good peace of mind. Whatever you do, do NOT use assembly lube on the bores or piston rings. ATF is best but clean engine oil is ok.

Alan

AntC · Post by **AntC** » Thu Oct 01, 2015 5:36 pm

bigaldart wrote:Hi,

The camshaft coating helps with break in and should not be removed, just clean the bearing surfaces if there is any residue on there, sometimes they use a greasy preservative, a pit of petrol as a solvent usually gets rid of it. Use plenty of clean oil on the journals when installing in the block. The orange paint will just be for the manufacturer and stockists to identify the cam quickly. There is no need to remove it. Make sure you use a good assembly lube on the can and followers, Crane is very good, if you can get it the old assembly paste that came in a black pot is excellent, the current red liquid that comes in a bottle works just as well though, I also use this on the mains and big ends together with piston pins if they are fully floating. It clings well and as we often have the engine sat for a month or two before running it gives good peace of mind. Whatever you do, do NOT use assembly lube on the bores or piston rings. ATF is best but clean engine oil is ok.

Alan

Thanks Alan - very informative. I haven't used assembly lube on the mains and big ends, just lots of oil. I plan to rebuild the engine and fill the sump to the correct level and occasionally pump the oil round using a tool on the oil pump drive off an electric drill. It will be some time before I start the engine and although I have heard that priming the oil pump can be done with vasalene I would like to see some oil pressure on the gauge before starting it up and I need to run in the camshaft. However, using it on the cam and followers sounds good advice.

bigaldart · Post by **bigaldart** » Fri Oct 02, 2015 5:35 pm

You should still prime the pump with vaseline, the Rover pump really is poor at self priming, any time the sump is off so the pick up is exposed it will need priming again. Believe me when I say we have tried every possible method to avoid taking the pump cover off as we drop the sump and check bearings after every meeting on the race car. Most methods work sometimes but not reliably and we then ended up losing track time, now we just pack the pump every time.

Alan