Club 80-90 Forums

Hi and welcome to another rebuild thread. I have decided to get my self a few more horses under the engine lid by building an MV engine and had the good fortune to be able to get hold of some of the parts from another member of 80-90. I have just finished cleaning everything up and am at the stage of measuring to see what needs to be replaced. So far the crank looks very good all journals appear to be round and still at original sizes, 60,55 and 40 mm. The pistons look great also needing new rings only. I have checked the rods out for ovality and they seem ok although there is some play in the small ends which may require replacing. So far I have fitted new non-stretch bolts to the rods and new valve guides to the only head I have looked at yet. The valves were all trash so I have used some spare inlets I had but have ordered 2 exhaust valves. I am going to replace all the studs for exhaust, waterpump, oil pump, water outlet, oil filler etc with stainless studs and nuts etc. I have put an old piston ring in one of the liners and the gap measures 0.6 so I am hoping that the liners will be ok with a hone and new rings with which the gap should be smaller!!
The big issue is going to be the early DG case (DG004572) which will require early main bearings and single thrust cam bearings. It will also need carefully looking at with the crank in place to see if a small amount of clearancing will be required on the back of where the head studs screw in (as the case will be slightly smaller than the MV case which was broken)
Any hints and tips as to any of the operations I need to do will be gratefully received especially with references to the clearancing. (I know Go-westy have used these cases for 2.1 builds)
Here are some pics of my messy workshop.(shed)
http://s1275.photobucket.com/user/123-j ... %20REBUILD" onclick="window.open(this.href);return false;

I think you will find that the double thrust cam bearing set will fit, they did on my buggy engine and that's a DG case with early main bearings. enjoy the build

If your after more power is there really a lot of point to build it as MV spec? Surely if you going to go to all that effort of building the thing isn't now the time to spend a few £££ more and get a set of DJ pistons in there?

Ideally a set of DJ pistons would increase the power more but The MV spec will give just enough extra I hope and in the future could be lightly blown with a turbo without issues whereas the DJ cannot be blown. It would be nice to use gas injection with 4-6 lbs of boost which may make towing my light caravan an option. A set of DJ pistons is around 350-400 pounds but would not leave the turbo option open.

There's a set of DJ pistons on ebay at the moment for a good price. I can't tell whether the third picture shows a bit of a ding on the edge of one of them, but for £30 they might be worth a look.

http://www.ebay.co.uk/itm/VW-T25-Transp ... 1902903477" onclick="window.open(this.href);return false;

123-jn wrote:The big issue is going to be the early DG case (DG004572) which will require early main bearings and single thrust cam bearings.

If you need some mains with that flanged bearing, rather than the later ones with separate thrusts... I am sure the one with the flanges is just from a type 1 or type 4 Aircooled motor, so you may just have to buy two sets of mains, and mix and match to get what you need.

Thanks CJH i'm not sure if they will be any good but they are winging their way to me which will give another option maybe!!! I have just been attending to the cylinder heads. The first head had 4 sloppy guides so I replaced them and re used two good inlet valves. The exhausts were no good so I ordered 2 but I'm not entirely happy with them as although the play in the guide is now acceptable it is not perfect. I had them from TES and they are made by Gieffe? Any one know of this make? Anyway I'll look into that. The second head had good inlet guides but the valves were starting to break up on the edges see picture!! On this head I changed the exhaust valve guides and re-used some good exhaust valves that I had in my spares box. Used but in excellent condition and VW!! This time I ordered my inlets from brickwerks, Jolly nice they are too.
In the pics you will see how I removed and replaced the guides. I am certainly not saying that this is the right way but it works for me!!! I tap the old ones with M10 and use a bolt and deep socket to pull them out. I use a copper nut underneath the socket to protect the casting. I then clean the bore and oil the new guide, then tap it in with a small hammer or if in a workshop I would use an air hammer. Measure the height so it is as the old ones were. (6mm proud)
Next its lapping time!! (I may need to recut the seats in which case I'll have to borrow some three angle stones from a mate!!!)
http://s1275.photobucket.com/user/123-j ... ead%20work" onclick="window.open(this.href);return false;

123-jn wrote:I tap the old ones with M10 and use a bolt and deep socket to pull them out.

I do something similar, I tap them, screw a bolt in, but then slip a long drift down inside from the other end and knock them out.

It seems that you can still get the early 1 piece thick walled bearings so thats good!! I just need to recheck the journals on the crank to make sure all is good for standard sizes. Next I need to trial fit the crank and a piston and see how much clearancing is required and where in order to fit the 76mm crank. hopefully it won't be too much of a job. I'm still waiting for an m16 tap to tap the oil gallery for the second pressure sender below the water pump. I can the fit it with a sump sensor adaptor to take it down to 1/8 npt. I am also trying to replace the studs for the w/pump, oil pump and water outlets with stainless studs but some of the old ones just don't want to unscrew!!

123-jn wrote:I'm still waiting for an m16 tap to tap the oil gallery for the second pressure sender below the water pump. I can the fit it with a sump sensor adaptor to take it down to 1/8 npt.

Why the need to change it from the normal M10 sender hole?

If you want a 5-bar output for a oil pressure gauge the way I find the nicest is to use one of those VDO dual output senders, but isn't enough room to screw them directly into a WB... so you have to make up a length of steel tube or braided hose with the relevant M10 ends on to remotely mount it where there is space.

I am also trying to replace the studs for the w/pump, oil pump and water outlets with stainless studs but some of the old ones just don't want to unscrew!!

I never have a lot of luck using stainless with stainless... like using stainless nuts on stainless bolts, I find it just tends to bind up when you go to undo them next time.

I will sometimes use stainless nuts on mild steel studs, or stainless bolts into captive threads in steel... but personally I think stainless nuts on stainless studs is a recipe for disaster.

I have to tap a thread as the early engines did not have a sender in this position so I removed a core plug to the oil gallery and am tapping the hole with M16 which is the best match for the core size and also luckily a size in which they do adaptors to m10x1 or 1/8npt. As for the stainless I was not aware of this problem with nuts and threads binding? What causes that then? I'm glad I haven't really started that yet!!!!

Use a dab of copper grease and you shouldn't have a problem.

123-jn wrote:What causes that then? I'm glad I haven't really started that yet!!!!

Just stick something like 'stainless thread galling' into your search engine of choice, should be plenty of stuff about it.

Meta flux is the product of choice when dealing with stainless fittings - not cheap though.

Thanks Enzo79 I've just read up on stainless galling, I never knew that!!! It looks like I would be better to use brass nuts where that is possible to avoid the problem and lots of antiseize elsewhere. Thanks for your advice which has saved me some issues!!