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About to rebuild my engine

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I'm about to pull the engine on my 84 mk2 breadvan and I'm going to fully rebuild with some gt parts and porting work for fun. Is it worth doing the bottom end too? I was thinking of leaving it.

 

Is there anything engine/not engine related that you guys would recommend I take a look at and replace whilst its out that I might not know about?

I can see theres a bunch of full engine gasket sets on ebay... is there a particular one I should go for or will any do.

 

I'd like to work on the gearbox too, again is there anything I can replace in there? which oil does it need and how much?

 

Cheers

Edited by Bevlesskeg

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What level of experience do you have as a rebuild requires a level of skill and patience

If you have the engine apart it is worth checking the condition of the crankshaft, the condition of the main bearings, the end float of the crankshaft, crankshaft oil seals and cleanliness of the oil galleries. If the engine is high mileage, then this is all worth doing especially if you are considering performance upgrades. If you are concerned that there is a history of corrosion in the block it is worth pulling out frost plugs to see if there is a build up of corrosion in the block compromising block cooling. New frost plugs are easily available on line. A well known German manufacturer of gasket set is fine. The cam cover gasket is one that has got to be good. Your engine may be the mechanical head so it may have a different seal. It will be annoying if that leaks as well as the bolt seals on the cam cover. All the bearings and seals can be replaced in the gearboxes; the 5 speeds easier than the 4 speeds because the bearings are taper roller bearings instead. The seal at the front of the gearbox that seals the primary shaft is not a standard size. You have to have the correct one or oil ends up on the clutch. Replace the clutch if you have the gearbox off. Check that the engine breather is clear or pressure builds up in the engine and forces oil out. I use the synthetic oil grade recommended by VW. I can't remember the grade. That will be found in the owners manual. Change the water pump because you will get good access to it. A silicon grease around the water pump seal will prevent it seizing and allow it to move easily so the cam belt can be tightened. A common fault is the oil leak from the oil gallery at the front offside of the engine that leaks on to to the alternator. The quality of the head gasket and the flatness of the head and block minimises this oil leak. I put some sealant around here as well to stop this leak if possible. All my experience is with the hydraulic head. If you have a mechanical head, then there will be differences.

Rubber engine mounts?

 

I'd replace the alternator and starter cabling and earth straps. Maybe change from Lucas plug to 8mm stud connection style alternator.. 

There are 2 sump bolts at flywheel end which I guarantee will drive you nuts. Later flywheels have a recess to let a tool reach them and Vw suggest different bolts (inner hex bit I think) 

 

If you are going to port a mechy head you could get bigger inlet valves fitted (Ford Pinto or Transit exhaust valves 8mm stem 36.2mm head, ~110.6mm long) to make it worthwhile.

 

 

 

 

research what its going to cost then add a bit , i lightly refreshed my abd , it cost way more than i thought and there was lots of could have done that i didnt , plus you need the tools /measuring equipment etc

 

you could get a low miles great runner much cheaper than a proper rebuild

If there are no problems with the gearbox, my advice would be to leave it alone unless you have the measuring equipment, a dial test indicator (DTI)  and a means of measuring pre-load being the minimum.

If you do decide to change bearings, be sure to change both the cup and the cone on taper roller bearings, as it is tempting to re-use the old cups but is VERY bad practice.

 

With regards to the engine, it would be as well to at least check the crankshaft and bearings, especially as you are looking to increase the performance.

You will find information in most manuals with regards to measuring the crank pins and journals, but what you are looking for is general wear, taper and ovality.

Check the cam noses are free from flaking. Measure the lift of the cams and compare with data.

Any unusual wear on any one cylinder could be an indicator of a bent or twisted con-rod.

 

Regards

  • Author
On 14/08/2019 at 18:14, kiran_182 said:

What level of experience do you have as a rebuild requires a level of skill and patience

 

The closest I’ve got to rebuilding an engine with a car is replacing the cyclinder head etc. I’ve fully rebuilt motorcycle engines with porting work etc. I’m pretty knowledgable and a quick learner and that’s what this is about really, I’m loving my car but it’s dieing for an engine refresh and it really interests me to try it. I have a gt cam and the pump needed, also a gt 421 exhaust. I honestly just want to rebuild and have a tinker and whatever results I get is great, I’ll be happy with a peppy healthy engine. 

 

 

Edited by Bevlesskeg

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Thank you everyone who replied this is all great.

  • Author

How can I tell if I have the mechanical or hydraulic head? I’m not too familiar with the difference.

1984 could be either mechanical or hydro head I believe.

Anyway the quickest way to tell is from the cam cover. If it is held in place with 3 bolts on top then it is a hydraulic head. 

If it has ten small bolts around the outside then it is a mechanical head.

it's a good buzz when rebuilding for the first time especially when it works at the end.

its alot of effort and you wanna be doing it in a garage, get cheapy engine stand and crane from ebay.

 

yeah it costs more but its about if you wanna learn more about engines. you said you was a quick learner and i presume you think alot about what your doing so i think aslong as the environment is right you to build your engine i.e plenty of time and somewhere good to store and money not an issue , then i say go for it.

 

I would like to say one thing though. When i went through the whole effort i made sure i built a really good performance engine. not just a standard engine so that it was worth my effort. each to their own.

take plenty of pictures and do a write up if you want. ive done a write up, going to get someone to check it through before putting it out on here.

  • Author
3 hours ago, damunk said:

it's a good buzz when rebuilding for the first time especially when it works at the end.

its alot of effort and you wanna be doing it in a garage, get cheapy engine stand and crane from ebay.

 

yeah it costs more but its about if you wanna learn more about engines. you said you was a quick learner and i presume you think alot about what your doing so i think aslong as the environment is right you to build your engine i.e plenty of time and somewhere good to store and money not an issue , then i say go for it.

 

I would like to say one thing though. When i went through the whole effort i made sure i built a really good performance engine. not just a standard engine so that it was worth my effort. each to their own.

take plenty of pictures and do a write up if you want. ive done a write up, going to get someone to check it through before putting it out on here.

 

Ok I have a mechanical head.

 

yep, I have a very equipped workshop as I’m an engineer and metal sculptor by trade. I have a 3 tonne engine lift that I’ve been using to move a massive cnc lathe about so that should do!

 

i am self employed and have a lot of time off starting in September. In an ideal world I’d have it out for a couple of weeks and just attack it all at once and have it ready before winter

try ebay germany for the parts...got alot of mine there , quality brand names for ok prices 

You could consisder fitting a longer duration camshaft:

 

BGA used to do one (CS5394 from memory).

or 

Ajusa 93010700
for (229 degrees at 1mm)
for example
 
Good luck finding new solid lifters though.
 
 
maybe these ---- never heard of this vendor though
 

Edited by dvderlm

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