engine overhaul

i got a 1.8 gti engine (dx i think)i want to overhaul with new bearings, seals, belts and gaskets. planning to sand blast and tart it up a bit too

just after a few tips you think may need?

wheres the best place to get hard to find parts?
i got two engines so i can make a good one with parts from the two

what parts can you only get from vw?

what mods can i do whilst the engine is in bits?

cheers for any help

hi mate.

get a nice working space.
a load of clean neat cardboard. (tesco)
a tip ex pen, (tesco)
a sharpie pen. (tesco)
money bags (bank)
freezer bags (tesco)
gunk engine cleaner (Halfrauds)
hylomar blue gasket sealant (GSF/ebay)
engine build lube (ebay)
Caustic soda oven cleaner (Kleenoff spray foam) (Tesco)
A top gasket kit, bottom gasket kit (GSF / EBAY)
Bottom end bearings, Cam shell bearings, piston rings

take loads of pictures of the tinyest details then proceed to strip it keeping EVERYTHING in order, where the valves came out exactly, which valve/piston rod ect went in each cylinder

clean each bit, number with sharpie/tipex

take the block and head to an engine place and get them to skim the head and block and work the bores

put it all back together.

done.

Chriselias272 said

hi mate.

get a nice working space.
a load of clean neat cardboard. (tesco)
a tip ex pen, (tesco)
a sharpie pen. (tesco)
money bags (bank)
freezer bags (tesco)
gunk engine cleaner (Halfrauds)
hylomar blue gasket sealant (GSF/ebay)
engine build lube (ebay)
Caustic soda oven cleaner (Kleenoff spray foam) (Tesco)
A top gasket kit, bottom gasket kit (GSF / EBAY)
Bottom end bearings, Cam shell bearings, piston rings

take loads of pictures of the tinyest details then proceed to strip it keeping EVERYTHING in order, where the valves came out exactly, which valve/piston rod ect went in each cylinder

clean each bit, number with sharpie/tipex

take the block and head to an engine place and get them to skim the head and block and work the bores

put it all back together.

done.

Do you work for Tesco by any chance  

Get the haynes manual and read the engine overhaul section first.

Aquire an engine stand to mount it to, makes it so much easier to work on than slipping around on the floor and oil leaks/drips can be contained.

Follow the tips and instructions for checking the various components in the haynes.

It may be that very little actually needs to be replaced.

The pistons and bores may be fine- but you need to measure them first.
If you go for an overbore, then youre into replacing pistons and your costs are going to go up.

Skim the head only if its warped or damaged on the sealing face.

Main and big end bearings are usually worthwhile changing but you need to be scrupulously clean with putting it all back together or theyll be as bad as ever after a few miles.

Read, read and er read some more on the engine dismantling and assembly process, then work out how youre going to keep everything youve taken off and cleaned  in that state whilst other items get attended to.

The block for instance- if youve already stripped it, cleaned it and painted it,put it back on the stand and bag it with new bin liners to keep dust and crap out of it.
Re- bag it every time you leave it to go do something else so it stays clean.
Itll last longer.


Performance wise, and depending on the budget youve got, go for new plugs correctly gapped, new clean air filter ( can be a stock type), leads cap and rotor.

Get the timing and fuelling checked so its running properly.
Those things are pretty much "free" compared to the alternatives which are modifying heads, changing cams etc.

My one word of advice is don't skimp on anything.
If you dismantle the big-end or main bearings then you will need new bolts.
When I did mine (many years ago) I didn't change the bolts and then when I torqued everything up again you couldn't turn the engine over (by hand) - doesn't take a lot of 'stretch' in those bolts to make a difference!
Other than that isn't an impossible job, just keep everthing eally clean and labelled. The satisfaction you get out of rebuiliding an engine is worth it!

paceman said

My one word of advice is don't skimp on anything.
If you dismantle the big-end or main bearings then you will need new bolts.
When I did mine (many years ago) I didn't change the bolts and then when I torqued everything up again you couldn't turn the engine over (by hand) - doesn't take a lot of 'stretch' in those bolts to make a difference!
Other than that isn't an impossible job, just keep everthing eally clean and labelled. The satisfaction you get out of rebuiliding an engine is worth it!

Couldnt agree more with the statement on skimping, it nearly always comes back and bites you later on.

Yes change the big end bolts unless theyre the "rigid" type.
They can be reused, the stretch bolts cannot, theyll let go sometime in the future, so swap em out.
Note of caution when changing big end bolts- do not attempt to pull the bolt into the conrod by tightening its nut, itll expose the bolt to tensile forces that can easily stretch the material past the yield point and youre into needing new bolts again.

Correct method is to press them in from above, protecting the conrods parting face with a sheet of aluminium or copper with a hole drilled in to accomodate the bolt passing thru it.

Regarding your tight crank experience.

This is either down to misaligned, or mixed up bearing caps, or bearing clearances that are too tight, the bolts being overtorqued wouldnt create that symptom.

Procedure to prevent that ever happening again in the future is to fit the centre main cap and torque it.
Then rotate the crank.
If it wont rotate, plastiguage the journals and ascertain the bearing clearance ( you should do this anyway- i always do).
Then move on to the next bearing cap and do the same thing.
That way, if a bearing goes tight, youll know which one and can address it immediately.

Heres what a properly checked crank with correct oil/bearing clearances should spin like ( very low torque).

Photo and Video Storage | Photobucket

Overboost, thanks for that info.
I will bear that in mind when I get round to rebuilding the engine (again).
Car had been off the road for about 10 years, trying to do the bodywrok first but just never seem to have the time!