Club 80-90 Forums

Hi,

Nightmare!! Have just taken our engine out to give it a well needed refit and have discovered 5 cracks in the cylinder head!! [I guess that would explain the 1Litre per 60km coolant loss!!] Has anyone heard of 5 cracks in the head before?

I do have access to a head from a mk2 golf though, so hear lies my question, does anyone know if it is possible to put a Mk2 cylinder head on a jx block in a Frankenstein kind of way?

I can see only one difference in the size of the oil drain hole on one side but as the engine is on a greater angle in the t3 i guess this wouldn't matter that much..
Has anyone done this? are there any Frankengolfs out there?

The van is a t25 1.6td 1989 and her name is jelly.

thanks

Is the M2 golf diesel or petrol & JX engines use shims for tappet setting.But M2 diesel golf engines are hydro tappet self setting this uses oil filled buckets.The head gasket diffrences need to be compared against the JX block but from memory there is a additional oil gallery on the M2 engine block proberly to facilitate the hydro tappet arrangement.Carnt help you to much on this but if the cracks are between the inlet&exhaust valves this does not mean that they extend into the coolent cuircut.Ive worked on a few VW 1.6/td & 1.9 heads and cracks like that are common & provided the cylinder head is flat on refiiting with a new gasket cause no problems.I suggest you get the head pressure tested by a engine repair shop .

The mk2 is a diesel and from what I can see the tappets and buckets for both are self setting hydro type and look exactly the same.

Will check the aditional oil gallery tomorrow when back in the workshop. Is this for drainage of oil from the cylinder head down to the block? If so the 50 degree tilt of the engine will arrow the oil to drain from the opposite side just like the old jx head. I'm very interested to see if anyone has done it and it worked?

Suprised the JX cylinder head has hydro buckets there may be shims .I carnt answer your question will it be okay i no about the diffrences in head gaskets ref extra oil gallery .Others on here will advice.

camper wrote:Is the M2 golf diesel or petrol & JX engines use shims for tappet setting.But M2 diesel golf engines are hydro tappet self setting this uses oil filled buckets.The head gasket diffrences need to be compared against the JX block but from memory there is a additional oil gallery on the M2 engine block proberly to facilitate the hydro tappet arrangement.Carnt help you to much on this but if the cracks are between the inlet&exhaust valves this does not mean that they extend into the coolent cuircut.Ive worked on a few VW 1.6/td & 1.9 heads and cracks like that are common & provided the cylinder head is flat on refiiting with a new gasket cause no problems.I suggest you get the head pressure tested by a engine repair shop .

Yes part of the reason I got my T25 WBX cheap was because the owner had discovered cracks between the valve seats. I replaced them with the reconditioned heads he gave me but it still lost water and boiled. after scratching head through to the bone I pressure tested the system and found the presure release cap (little blue darlek gismo) leaking under pressure. These particular cracks although not exactly confidence building are mentioned in the manual but I can't remember the acceptable measurement.
Cheers
Wolfi

http://s742.photobucket.com/albums/xx62 ... g&newest=1


Me thinks this baby is going to be a lamp holder in the livingroom.

Cracks extending to the swirl chambers i have not see that before.Whats the price of scrap aluminium?

so anyone done the jx block and mk2 head?

[quote="camper"]Cracks extending to the swirl chambers i have not see that before...quote]
Mine had the same cracks.

I believe the evidence as on the image i wonder what causes those cracks.On the 1.6/1.9 deisel heads cracks between the valves seem common and dont mean problems with loosing coolent

camper wrote:I believe the evidence as on the image i wonder what causes those cracks.On the 1.6/1.9 deisel heads cracks between the valves seem common and dont mean problems with loosing coolent

I guess it is to do with how the castings are stress relieved after the moulding/casting process and how the particular form responds to that process. Stress relieving - sometimes called normalising - is mostly done by heat treatment in the form of controlled cooling rate or some kind of thermal cycling. Ideally the casting will be free from internal stresses prior to machining but as we live in an imperfect world some will inevitably remain. Then as metal is removed during the machining process these stresses end up on the surface and congregate like yobs with asbo's along thin unsupported edges and in corners. The thin metaal between the valves is an ideal example. Once the crack has released the stress all is fine unless there is a leak or the mechanical integrity of the casting is violated.
Cheers
Wolfie

the difference between the mk2 and jx cylinder head is one oil drain extra on the mk2 head as the engine is almost vertical as opposed to the jx only has 3. The jx only needs one on the lower side due to the tilt. When I marry a jx block up to mk2 head the extra oil drain lines up with a coolant chanel. What does anyone think about the posiblity of plugging the extra oil drain (as it's not needed) and installing a mk2 head on a jx body? It won't hamper coolant flow around the block in doing this. has anyone thought of this or done it? We have the possibility of doing a propper weld to seal this extra chanel and so this is a real practical possibility. Do you think there may be a hot spot on the block in operation? Will this be the only one like this in history if we go ahead?

If this is a no go it will have to be a new jx cylinder head, so if that's the case has anyone got a used one that's in good nick and only needing a skim?!

if its fooked chuck the whole thing out and fit a aaz

loads of them in older passats etc.......

scrap it and get a fireblade