Engine Strip Down

[Tatey]

I'm looking to strip down, clean up and paint my newly acquired 1.8 cvh engine, i've never seen it running, and i dont even know if it is a runner (i managed to get it for free), oh and the sump has a pickaxe shaped hole in the bottom of it.

Does anyone have any tips on how to strip it down, how far i should be stripping it down and what i should be doing to it once its stripped down?

Cheers

[mark]

Firstly i hope that hole wasnt done when it was running and it lost all its oil :eek:

There are enough engines out there to use one that you have heard running and know the history of but if you really want to use it The first thing i would do is take the plugs out and try to turn it over by hand if it turns with out any strange noises and just the sound of compression its a good sign!

Im not a mechanic by trade so i will leave the rest for them to get their teeth into :D as they have years of experience and im sure later today you will have a list as long as your arm to check ;)

[gus]

I had never heard my engine running. Bought the donor with a snapped cam belt. Why is it a non runner? Already stripped from car, or is there something else wrong with it? (Other than hole in sump).

If doing full strip down I would check the following things.

1. Head for belt valves, burnt valve seats. Replace valve stem seals anyway.
2. If the cam followers can be compressed by hand then they need replacing. (Two of mine where knackered.)
3. Check cam lobes for wear.
4. Check bores for scoring. Piston rings breaking up is a known fault with these.
5. Piston wobble. If excessive, might need rebore & oversize pistons.
6. Crank should rotate freely with head off. If notchy further strip down required. Could be main bearings gone.

I must add I am not a mechanic, a mate of mine rebuilt the engine for me. Started first time when we tried it.

See below link for youtube video. Bit blurry, taken on mobile phone.
http://www.haynes.co.uk/forums/showthread.php?t=2739

Hope this helps
Mark

[Tatey]

The engine had already been removed from the donor car, which is why its a none runner.

Cheers for the advice.

I've taken the silver bit off of the top (im new to the whole engine scene, feel free to tell me the actual names of these parts, ill happily learn them). I got a bit overwhelmed by the look of valves etc, so stopped stripping it from then. What do i do after i've taken the top part off? Which bolts allow me to remove the head?

Cheers

[flyerncle]

If the hole in the sump metal is pushed in over it may be ok, if any of it is pushed out over it may have dropped something internal and burst out of the bottom of the sump.
Hopefully some knob has just put a hole in it !

The bit you have removed is the rocker cover ,there are 8/10 bolts that hold down the head and they are evenly spaced under all the oil and crap,once you get the head off there are small dowell pins in the block don't loose them.
Put the pistons level in the block about half way down and put enough parrafin or diesel in the bores to cover the piston and leave it for a while and see how long it takes to run down,if it goes quickly its knackered and the bores/rings/pistons are worn.

[Tatey]

Andy picked up the donor parts, and i think the guy said to him that he accidentally put a pickaxe through the sump which trying to lift it up...:eek:

[gus]

Did you get the engine wiring loom or are you planning on going down the bike carb & megajolt route?

If donor car is still about, and you haven't got the loom it would be worth getting it with the ignition control unit.

[Tatey]

Cheers for the tip flyerncle. I'll try and take the head off tonight and see how things look. Although when i took off the rocker cover, it all looked pretty clean, is this a good sign?

Im afraid i dont have the engine loom. I didn't realise that this was going to cause me much of a problem. So because i dont, and because the donor car is no longer available, does this mean i need to go down the bike carb/megajolt route? If so, i dont see that as being too much of an issue for me, because i am eventually planning on upgrading to a 2l zetec engine, so i'd need them eventually.

[gus]

Being clean inside the rocker cover is always a good sign. These engines can be prone to gunging up the oil around the rockers. Thick oil / sludge in there could also be a sign of the rings being knackered, and letting exhaust gases into the oil.

Not having the loom is not a major problem if you are going to go down the bike carb route eventually. Better to do it sooner rather than later. Just for a budget build if loom was avaliable could be a bit easier & cheaper getting you on the road quicker.

Cheers

Mark

[Tatey]

Are there any recommended bike carbs for the cvh engine?

[Bonzo]

I'll second flyerncle's advice ;)

Pound to a penny that the hole in the sump was made to drain the oil :rolleyes:
Our local breakers punch a hole in the sump rather than undo the drain plug

Worth checking the exhaust ports for signs of burning oil ( Black & greasy ). CVH engine valve seals tend to leak if the engine has not been well mantained or covered high mileage .

New valve seals will be included with a head gasket set :)

Parts wise, Head gasket set, bottom end set, timing belt ( renew timing belt tensioner if unsure of condition )
Inspect the water pump ( renew if in doubt )
New spark plugs, leads, rotor arm & dizzy cap if required
Oil & filter

[Tatey]

I took a picture of the valves etc last night:

http://i292.photobucket.com/albums/mm22/Simon_Tate/DSC01201.jpg

Does this mean that my engine could be all right?

[dogwood]

OH MY GOD ...NOOOOOO...:eek: :eek: :eek:

The zurgon disintegrator reflector shield has gone



Only kidding.:D
You need to go further, before you know if it's a goodun.
Might be worth taking the sump off, see if there is any nastys lurking.


David

[spud69]

Hello Tatey,

In my experience with the CVH i would remove the sump and head and remove each piston and check for any play or signs of wear on the big and little end. Both sets of shells are quite easy and cheap to replace and also the piston rings while you're at it. With mine the cvh was running sweet in the donor car but as soon as it started getting pushed the big end went to the extent that a crank regrind just wasn't worth it (well thats what i told the good lady to upgrade to a new zetec).
Also check the hydraulic lifters, these can fail or oil ways block after high mileage and again are not too expensive to replace. Also when modifying the sump retain as much volume of oil as you can with the pick up pipe in the correct position, its also worth adding an oil pressure gauge on the dash just for peace of mind.
Just from my experience but that is my plan with my next cvh.

Enjoy.....AndyH

[AshG]

on my pinto i removed the head and sump replaced all the gaskets and seals cleand up painted it and put it all back together. total spend £40 ish. these old engines are 10 a penny is it seems pointless throwing loads of money at them when you can buy another whole engine for less than a set of big end bearings.

i dont expect loads of people to agree with the above but in my opinion its much easier/cheeper to replace an engine of this type age than it is to repair.

im plan is to run the 1.6 pinto until it pops then change it for something with a bit more poke :D

[semtexsteve]

hi mate i am just finishing my cvh rebuild and got a big tip for you replace everything when i took my rocker cover off everthing inside was covered i thick black slime so the first thing you need is a parts washer i got mine from screwfix for £50 best £50 i ever spent then i striped and cleaned the gunk off then i was super brave and when the wife was out i put it all in the dishwasher ( see my preveus threads ) . I got all my new parts from ebay

fuel pump £9
gaskit set £22
piston rings £27
theromstat £3
bearing shells £29

for that kind of money you cant afford not to and as it is all apart now now is the time to do it . as a pint of refarence i have just had to put a new fuel pump in my mondeo £200 just for the part

[Tatey]

Well as a reward for doing a fair bit of uni work yesterday i decided to have another go at stripping down my engine, with a bit of common sense with a spanner and a breaker bar i managed to get the crank pulley off and got the head off, here are some pics. From the pics could someone tell me if my engine could be a runner?:

http://i292.photobucket.com/albums/mm22/Simon_Tate/DSC01212.jpg

http://i292.photobucket.com/albums/mm22/Simon_Tate/DSC01220.jpg

Oh and flyernycle i did the tip you said, i put a small amount of petrol in each cylinder when they were all at the same level, after 5 minutes the amount didnt seem to have changed at all.

Also could anyone tell me if my clutch is any good?

http://i292.photobucket.com/albums/mm22/Simon_Tate/DSC01214.jpg

http://i292.photobucket.com/albums/mm22/Simon_Tate/DSC01215.jpg

Also does anyone know why there is a Bosch spray can lid on my engine? Any idea what its there for?

Also could someone give me a quick list of all of the engine parts i need to get my roadster running e.g. engine, carbs, alternator, fuel pump, starter motor, battery, loom.

Cheers

[Land Locked]

Looks like no1 cylinder had some water in it. This could have damaged the cylinder wall and or rings.

The head from what can be seen looks quite good.

The clutch is near impossible to check without having it in hand. The friction surface looks okayish, but there is so much more to it than that.


I would finish stripping the block, check the bores for wear or have them checked. If they're good hone them throw in a new set of rings and bearings. The head would also benefit from a strip and at the very least a set of valve stem seals and grind/lap the valves.

That of course is just my opinion from what can be seen in the photo's, the bores and pistons would need proper checking.

Edit: It would be a really good idea to get a Haynes manual that covers the CVH motor, the manuals generally have really good engine sections.

[car.mad]

dosnt 'look' too bad but you can never tell by just looking at it

would probably benefit from a good clean up make sure all the gunk is out

then like someone else has said finish stripping it down, get the bores checked hone them new rings beatings e.c.t

so parts your probably looking at for the block...

Big end shells/journals
main shells/journals
piston rings
crankshaft oil seals
headgasket
timing belt kit
water pump
?? oil pump ??

with regards to the head id say strip it and new seals possibly new valves is there buggered... maybe a good idea to send the head to a machine shop and get it all checked there and the head skimmed but its up to you and how much you want to spend.

the clutch 'looks' ok but i personaly would put a new one in whilst its out, you can never be too sure

that 'paint can lid' is the oil filter that should be replaced.

[Tatey]

that 'paint can lid' is the oil filter that should be replaced.

Thats not at all embarrassing :D :p. Can you tell i havent spent much time around car engines :D

Im plan at the moment is to completely strip down the engine clean it all up and replace:

fuel pump £9
gasket set £22
piston rings £27
thermostat £3
bearing shells £29
+ lots of other bits

I dont mind if it takes me a while and costs me around £100, one of the main reasons for starting this project was to learn more about cars, engines in particular, so if i can take a dirty old engine and make it nice and clean again, and work at the end of it ill be more than happy :D

[Tatey]

I've now taken the pistons out of the block. And i'm just wondering what the locost way of cleaning all of the parts are? I've thought about buying a parts washer, but that could be a fair few months away due to lack of finances until i find another just. I'd like to clean up all of the parts and put the engine back together for storage for a while, until i get the funds to buy a new engine, it should give me some good practise as well.

Also i am having problems taking the exhaust manifold off of the head, it just doesnt seem to want to budge, is this common on a 20 year old engine? If so whats the normal method of getting it off? If its not common, does that mean i've missed a bolt? :D

[car.mad]

I've now taken the pistons out of the block. And i'm just wondering what the locost way of cleaning all of the parts are? I've thought about buying a parts washer, but that could be a fair few months away due to lack of finances until i find another just. I'd like to clean up all of the parts and put the engine back together for storage for a while, until i get the funds to buy a new engine, it should give me some good practise as well.

Also i am having problems taking the exhaust manifold off of the head, it just doesnt seem to want to budge, is this common on a 20 year old engine? If so whats the normal method of getting it off? If its not common, does that mean i've missed a bolt? :D

i would use wire brushes of different sizes to get the thick of 'it' the wheels for drills are quite good too

brake or carb cleaner is good at getting under the 'it' and just keep at it, did a old mini gearbox with wire brushes and a bit of thinners, got a good finish out if it

some light sandpaper works on aluminium bits aslong as you can get into the little nooks and crannys.

with regards to the manifold if its never been off before and exhausts get quite hot its not uncommon for them to be a little bit stubborn, first i would make sure you got all the nuts/bolts off then double check again, then give it a clout with a rubber mallet, thats what we do at work on old morris minor engines and it seems to work.

someone else might have a better idea though

Jake

[Tatey]

Cheers for the tips Jake!

How do you go about cleaning the pistons and valves etc to get all of the oil and gunk off of them? I've had a quick look on google and people have recommended petrol/white spirit to clean them, i can't see that solution doing much harm, but i could be wrong and you seem much more knowledgeable about the subject. Also what kind of oil would you recommend to use when putting it all back together to prevent rust?

Cheers

[car.mad]

no problem

yep petrol works aswell

for the pistons im not too sure but i would say again some sort of cleaner and an old tooth brush

if you are replacing the rings for the groves some fine sandpaper (1000 grit) folded over would be your best bet.

the oil that should be put in the engine is '5w 30 fully synthetic' according to a website but im not too sure probably best to check elsewhere and be sure. I would probably use the same oil the engine takes when putting it back together but any oil is better than no oil

not sure about the valves but somthing like the above should work. the valve stems themselves should just be clean i would avoid sandpaper here.

when you put the main and big end bearings back in only oil the crankshaft face... the other face on the cap needs to be as tight a fit as possible to the bearing

Jake

[Bonzo]

Personaly, I would avoid using petrol as an engine cleaner.
It poses a significant health & safety risk, Exposive, toxic & harmfull to the skin to name a few. :eek:

I have used Jizer as a cleaner for many years, water soluable & will air dry with the use of a blow gun. ;)

There are engine assembly oils out there, I tend to use plain ole Magnatex, does what it says on the tin.

Looking at that cylinder head of yours & at a quick glance it would certainly look as if it has blown the head gasket.
I would investigate if this is the case & then investigate why !!??

[Tatey]

How would i go about investigating if the head gasket had blown?

[flyerncle]

Bring the head and gasket down on thursday ! I hope you marked the pistons 1234 and which way they pointed Mr Tate !
Engine oil,back to the days of 20/50 maybe ?
You didnt did you ?:eek:

[Tatey]

Bring the head and gasket down on thursday ! I hope you marked the pistons 1234 and which way they pointed Mr Tate !
Engine oil,back to the days of 20/50 maybe ?
You didnt did you ?

I'll load it into the car and hopefully this time i can reverse into your garage without having to drive down the road, turn around and attempt it a second time :D

Is it much issue if i didnt mark them? :eek: :rolleyes: I have a rough idea what cylinder each piston came out of, as i have the pics and i havent cleaned the crap off them yet....

And i didnt do what.....? :confused:

Edit: I've just been out and had a look at the pistons and i now know which piston came out of which cylinder and which way round. May i ask why it is important to know? When i took them out, i thought to myself 'i bet i'll find out i need to mark these up'. Sods law eh....

[AshG]

sorry i have got some more bad news for you. looking at the clutch housing one of the 3 pressure plate springs is cracked (the one at between 7-8 o-clock on the picture)

http://www.haynesroadster.pwp.blueyonder.co.uk/clutch.JPG

[Tatey]

I've just been out to have a look and it appears to be just a section of dirt has been removed, making it look like a crack. I've taken pictures of all 3 springs and they all seem to be fine.

Cheers

[flyerncle]

You didn't mark them !
The piston and conrod fit a certain way in the block facing the front and thats what I meant so mark them front and 1 2 3 4, find out what size they are and get new rings and shells plus the center thrust's. To clean out the grooves break one piston ring from each of the three grooves and use the good end to remove the carbon. Check the top of the bore and see if there is a lip on it (black carbonised ring at the top)if this is large the block may need reboring. If not a glazebuster will do the trick ( yes I have one)!
Pop down on Wednesday and practice your reversing, I have reveresd artic's in to smaller spaces !!!!

[Tatey]

I've just been out and taken a couple of pics of the bores, im not sure how large the lip needs to be to be large:

http://i292.photobucket.com/albums/mm22/Simon_Tate/DSC01234.jpg

http://i292.photobucket.com/albums/mm22/Simon_Tate/DSC01232.jpg

Oh and i got this engine chucked in for free with my donor parts, so if it turns out to be a dud, then its not too much of a worry to me, as long as i can get some use or knowledge out of it im happy :D

[HandyAndy]

"Chucked" is the word, then again "Slid" is another one that springs to mind when we got it out of my van :eek: :D

shorty:eek:

[AshG]

the bores look good. if you can take pictures as good as those of all the shells journals bearings etc we should be able to give some advice although its never as good as inspecting the engine first hand.

it may be worth getting a sierra book that covers the cvh as it tells you what size all the parts should be to fractions of a mm. all you have to do then is look for damage and measure everything to check wear.

[Tatey]

I'll take a pic of all of the other little bits either tonight, or most likely tomorrow afternoon. Cheers for all of your help, i've learnt quite a lot already :D

Oh and i've got a digital copy of the sierra book which covers the cvh, so ill have a look at the measurements and see if i find any problems.

[flyerncle]

I agree with Ash it's looking good,bring a piston with you and a main and big end shell and we will see what they are like.

[Tatey]

Just to make sure i bring the right stuff tomorrow. The big end bearing is the two halves from the con rod and the main bearing is the one which acts against the crank shaft?

Oh and flyerncle we need to retrieve one of my lost sockets from when i tried to take out the spark plugs :D :p :rolleyes:

And....i haven't managed to remove the camshaft sprocket from the head and the plastic hit which goes behind that. Lets just say engines aren't my strong point at the moment :rolleyes:

[Tatey]

I'd just like the thank Paul for his help again on Thurs.

Paul said he thinks the engine had blown its head gasket, so the head will need to be skimmed, so thats another thing on the list of things to do :eek: :rolleyes:.

I've now managed to take off the flywheel, exhaust manifold (i found other eight bolts holding it on :D), rockers + cam followers (i think) and take out the crank shaft.

Im now just struggling with taking the crank pulley off of the crank, getting the camshaft pulley off and i need to buy myself a valve spring removal tool, but that will be once i get myself a new job.

So i've now started derusting the disk brakes and i think ill be doing some more work on my chassis over the weekend. Then once i can afford it i'll be buying some gunk and other cleaning products to start cleaning up the engine.

I would take some more pics but i've had to send my phone off for repair, and thats also my camera so it'll be a week or 2 before i get it back :(

[Land Locked]

I'll try n get a photo of the tool I made to compress the springs on a CVH head. Basically a fork that fit over the valve spring and rocker stud. Turning a nut onto the rocker stud compresses the spring.

Edit: When I say try n get a photo, I need to find the tool(not used it in years) and hope the crappy phone camera does the job. I really miss my camera that drowned.

[flyerncle]

Getting the valves out is no problem just use the plug socket over the valve cap and a sensible tap with a hammer will pop the collets out just make sure you dont lose them.
Like I said it's no problem and I will give you a hand with reversing if you like !

Spacial awareness Tatey !!!!!!!:D
Put a piece of wood inside the block against the crank and use it to stop it turnng and loosen the pulley bolt.

[Tatey]

I was about to reverse into the garage when a van pulled right up my arse and a car was coming the other way, so i thought wat the hell and i decided to drive on and turn around instead of having to sit there for ages waiting for the van driver to reverse and wait for the other car to then get passed, so technically i've only failed to pull into your garage once out of the 3 times due to my crappy driving :D

I've managed to remove the bolt from the crank shaft pulley, its just trying to get it off of the shaft is what im having difficulties with, the oil seal obviously still on the crank shaft so i cant get my trust hammer in position to give it a small tap :D :p In the haynes guide it says to use a puller, but i dont have one, has anyone got any ideas?

When you say plug socket im guessing you mean the spark plug socket?

Oh also, im having issues removing the spark plugs as my spark plug socket wont fit in the hole for the spark plug...go figure. Only my 17mm socket would fit, am i being really stupid here? (im guessing i am)

[flyerncle]

Yes spark plug socket,you need a 15/16 in socket (spark plug socket)

[flyerncle]

"so technically i've only failed to pull into your garage once out of the 3 times due to my crappy driving "

Poor excuse !:p

[Tatey]

Right im confused now :p. Isnt a 15/16 in socket, 24mm in metric? The spark plug socket i have is a 21mm socket and says spark plug on it, but it doesnt fit in the hole, do you get different sizes of spark plug? If so what size does the cvh engine use?

[flyerncle]

You are right,I was thinking (wrongly ) of a pinto. 16mm or 5/8 is the size.

[Tatey]

Ah cheers for that. Another thing on the list of things i need to buy :eek:. No one told me this kit car business would be expensive :D :p

[Bonzo]

Another thing on the list of things i need to buy. No one told me this kit car business would be expensive

Welcome to the joys of engine stripping :D :D

Buy the time you have finished spending on the engine rebuild........ £600 for a brand new Zetec engine will seem like a bargain :eek: :D

[Tatey]

Haha yeah.

I've been looking into nitrous oxide to give the cvh a bit more ooommphh when i get used to the power. It would appear that you can actually use nitrous without destroying your engine, as long as you dont go overboard and only have a 25-40% increase in power and it can be done for a reasonable price, e.g. under £200 if you buy the parts separately instead of in kit form. I'll still need to do lots of research as i've only just started researching it. But atleast its something to aspire to before i buy myself a zetec :p

[Bonzo]

At least you are geting a first hand insight into the workings of an engine during the CVH overhaul :cool: :)

That is one thing money cant buy ;)

[Tatey]

Yeah thats defiantly one thing i've really enjoyed doing, not many of my friends know how an engine goes together, atleast now i can say i kind of do :D

[HandyAndy]

all credit to you Tatey, when i need help on my cvh i know where to call :eek: :D

glad you are enjoying yourself:cool:

shorty

[Tatey]

all credit to you Tatey, when i need help on my cvh i know where to call
glad you are enjoying yourself:cool:

shorty

Atleast i'll finally be able to offer my 'skill' set to you, instead of the other way around :D :p

[Tatey]

Well i decided that i might as well continue stripping down the head today, all thats needed doing was to take the camshaft pulley off, remove the camshaft and take the valves out. I managed to get the camshaft pulley off by making a tool to stop the pulley from rotating and a bit of force from mr breaker bar.

I've taken out the little plate which stops the camshaft from coming out, but now I'm at a loss as to how to remove the camshaft oil seal. I don't want to destroy anything when trying to remove it in order to get the camshaft out.

So does anyone have an idea as to how to remove it?

Cheers
Simon

[Bonzo]

Personally, I normally prise oil seals out with a large flat bladed screwdriver ( Gently !! )

It'll FUBAR the seal but should not be a problem as a new seal will come with the headgasket set, in any event, should be replaced as a matter of course ;)

If you don't feel that confident !!, gently tap the camshaft forward a little & the oil seal should come out with it .

The CVH cam can be a little bit of a devil to get out once the cam is clear of the bearing journals.
Just be patient, keep the cam level & square to ensure it will pass through the next set of journals without snagging, ( Probaly need to rotate the cam a little too ) . ;)

One last thing, never tap or hit the cam with anything solid, use a copper or plastic mallett.
If you don't have one, a small piece of hardwood used as a drift will do no damage :)

[Tatey]

Cheers for the tips bonzo. I managed to get it out using a flat headed screwdriver and the camshaft came out with no issues, its now stored in a carboard box with my crankshaft and pistons. The only jobs i've got to do now are:

Remove the crankshaft pulley so i can remove the oil seal
Remove the valves (im planning on buying a g-clamp and modifying it to be used as a valve removal tool)

Then once all of that is done i can start cleaning up all of the parts and then wait until i have the funds to buy the following parts:

Piston rings
Headgasket set
Big end bearings (i dont think ill be buying main bearings at the moment as flyerncle said they looked fine, where as the big end bearings are through to the copper)
Get the head skimmed
Paint the block
Oil filter
Spark plugs
Thermostat

Im just trying to find the best price for the big end bearings now, any ideas? I've tried ebay but there dont seem to be many, enginestuff.co.uk seems to be the cheaspest, but i recon i might be able to find a better price.

[flyerncle]

Best advice is take crank with bearings to engine specialist like Engine services at Dunston (john) and get him to measure it and they can supply the bearings etc,it may be a good bet at this time to overhaul it completely even though it may cost a fair bit its good policy at this stage,last time I asked him all the bits and pieces were about £200.
As Bonzo says its not worth messing about with oil seals as they come in the head set and dont forget the valve seals.

[Tatey]

Is that £200 for the overhall of the camshaft with piston rings, big end bearings etc? As at the moment im looking at around £150 for everything to recondition the engine.

[flyerncle]

It was for the parts only,full set of shells,thrusts,and rings and gaskets,I personally will replace the core plugs as they will be dry and possibly rotten on the inside and for the hassle they will cause if leaking it's not worth it.
What I meant was if you got to see an engine specialist they can measure the crank etc and advise if it is ok or in need of a regrind and like I said previously John does all our engine stuff,maybe not the cheapest but never had any probs with him.:)

[Tatey]

Cheers for that Paul. How much do they normally charge for just checking the crankshaft and camshaft?

I think i'll get it all checked over before i start buying components in case it turns out its a dud and ends up being a money pit.

[Tatey]

Well i decided to shove my pistons in the 'parts washer' earlier on, they got rid of all of the grime, but the majority of the carbon on the top still remained, but a bit of scotch bright has sorted it out, i've still got 1 more to do, but the other 3 are looking like new. If i manage to get hold of a camera i'll take a picture of them.

Does anyone know how long the pistons might remain in this condition once i manage to get the engine fired up for the first time?

[Bonzo]

The piston crowns will take a fair few miles before they become encrusted with carbon once more :) ( Assuming ideal engine operating conditions are met )

Longer if you polish them ;) ..............Don't polish the direction arrows from the top of the crowns though :eek:

[flyerncle]

John I think would not charge you and if you are buying from him he is going to advise what is needed ie regrind or what ever,it is possible to put oversize rings in but not a diy for the fainthearted.He is the one I would trust to check it and supply bits. There is also Northern Rebore (Ronnie) in Elswick Road Ncle.