1.9 head on a 1.6 mech. block

[RabbitJockey]

that's what i thought, and i would definetly suggest upgrading the oil pump, especially for how easy it is to do an oil pump on these cars, whats it take like half an hour if you take a coffee break in the middle of it

[saurkraut]

I did a gound up rebuild on the engine about 4 years ago.  I used the biggest pump I could find at the time, so the pump is probably OK.   I suppose I'll just drop the pan when I have the head off and take a peak at the rod bearings and piston rings.  I can check the pump then.

Where does the oil enter the lifter bore on the hydo heads? If it comes in perpindicular to the bore, perhaps there wn't be a big issue.

[mk1TD]

It is possible to successfully put the 1.9 IDI head on the early 1.6 blocks, however the 1.9 head was engineered for a bottom end that was 300 cc  larger, so what I have found out is that the prechambers are larger in the 1.9 head to accomidate larger displacement.  Being that there is more volume in the 1.9 head, installing it on a 1.6 bottom end would result in lower compression.  I havn't ran the C.R. numbers but I too had this same set up with bad luck!
No doubt, the 1.9 head was far superior to the 1.6 head with the larger intake valves, 7mm stems, and the "D" shaped intake ports were awesome, but the lack of compression made it difficult to start when cold.  I ended up having to advance the timing to 1.15mm to help compinsate for the low compression(advancing timing to allow it more time for fuel to burn), but even with that it still was not nice.  When the engine was warm or tempuratures were warm it ran awesome!  I wouldn't recomend it to anyone.

[RabbitJockey]

if you're going to have it all apart you might as well do rings/rod bearings too. if you've got the time, i did rings and rod bearings headgasket new air filter oil filter and all the goods for like 140

[saurkraut]

I'm not to worried about cold starts.  "Cold start" for this engine will be 60 fahrenheit.  Its my summer rabbit.  I did some comp ratio figuring with the displacement difference and got 19.somthing to 1.  Its on my computer at work.

My main interest is is lower compression to put less stress on the rods, bigger ports and valves, and metal head gasket.

I suspect my rings are OK, but its worth a check.  I run Delvac 1 and drain every 3K miles.  Last time I did a cold compression check, about 40K ago, all cylinders were in the mid 400s.  I didn't measure my piston projection when I put it togather.  i went with the tree notch gasket head gasket.  So I'm probably spotting myself a couple compression points there too

I'll have to compaire the lifter bores on the 1.9 head to one of the other mech heads I have laying around and see what the difference is when it shows up.

[itzdshtz]

I don't think mechanical lifters in a hydraulic head will work, the mechanical valves are about 11 mm longer than the hydraulic valves.( the mechanical valve lifter is way thinner than the hydraulic one that has a piston inside it)

If you bore the block to a 3rd piston oversize or get some 80mm pistons from a 1.7 diesel may help with your compression ratio if you want to use the 1.9 cyl head.
Another option might be if you convert to 8mm valve guides and put some longer valves in from an Audi 2.0 TD or Volvo 2.4 TD.  This would be the significant fussing Andrew is talking about.

[RabbitJockey]

do what you want, but for the little bit of money and little bit of time it takes to do bearings and rings while ur in there i highly suggest it, but it's ur car and stuff

[saurkraut]

I want the lower compression ratio.  Its a summer only diesel.  I think the VW SAE paper said that the 23:1 compression ratio was chosen for cold weater start per formance.  Its not going to run in cold weather, so i don't need 23:1

Appearently, the hydaulic lifters are fed through the bottm of the bore.  Solid lifters would probably stay in contact with the cam constantly.  so i'm going hydro...

Yes, I'll pull the pistons when i take it down.  Yup, i know bearings and rings are cheap, I've bought enough of them.  Fear not.

I'm really dying to see if running 24 lbs of booste and a modified governor has scuffed any thing.

[saurkraut]

I'm discussing ceramic coating the swirl chambers with Swain Technology.
They haven't done any work on pre-chambers yet so I 'borrowed' pictures from posts on this sight and I think they have the idea now.

There is still somewhat of an issue with the coating process.  The cover and recess in the head must be coated sepperatly.  The injectors, heat shields and cut off glow plug will need to be in the head during the process to keep it from going into those areas.

The deposit is about .001" thick.  I don't want the coating in the area were the OD of the cup sits in the head.  Their solution is to mask it, and then hand dress the seam so it doesn't have a lip.

Thats the latest.

[saurkraut]

Here's the Swain Tech. Quote:


Thanks for getting me the information and photo's.  Now I have a pretty good idea as to what you have and what you are looking for.  Here are the estimates:
 
Thermal Barrier Coat Prechamber in the head: $170 for all 4 prechambers.  We would need you to send along glow plugs and injectors that we could use to mask those threaded holes and protect those surfaces.  We should have injectors and nozzles to fill each of the openings because we would process all 4 prechambers at one time.
Thermal Barrier Coat open end of cup: $24.50 each.
Thermal Barrier Coat exhaust port: $28.00 each.  We would not need the valves for the type of head you have.  We typically would not coat the exhaust port only but based on the images you sent we can probably coat them without too much difficulty.  It may cost a bit more than $28 depending on how much time they take to process but I think we can do it at or pretty close to the $28 each.
Turn time would be about 2 weeks in our shop.
 
Please let me know if you need anything else.
 
Richard