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Engine Specific Info and Questions => IDI Engine => Topic started by: saurkraut on December 02, 2006, 07:22:41 am

Title: 1.9 head on a 1.6 mech. block
Post by: saurkraut on December 02, 2006, 07:22:41 am
Just scored a new 1.9 IDI head.  I intend to put in on my 1.6 mech. block.

Anyone have a good solution for the extra oil return/coolant passage issue?

Also, as long as its brand new, I think I'll do the ceramic coating in the prechambers, head, and exhaust ports.  Any body had this done befor. and who did it?

Its going to be a winter project while my '79 hibernates.
Title: 1.9 head on a 1.6 mech. block
Post by: RabbitJockey on December 02, 2006, 07:38:48 am
just plug the extra hole and then it's basically a bolt on.  the aftermarket heads are designed to fit both mechanical and hydro engines, although it is a mechanical one, it has like a dummy extra oil drain with no hole in it.  just plug the oil drain then the head is basically bolt on just like a normal solid lifter head,
Title: 1.9 head on a 1.6 mech. block
Post by: RabbitJockey on December 02, 2006, 07:39:14 am
also, how does the 1.5td run compared to the 1.6td
Title: 1.9 head on a 1.6 mech. block
Post by: saurkraut on December 02, 2006, 08:11:57 am
The head is a NOS 1.9 head.

The extra oil drain hole is open.  i also want to run the metal HG.  I supose i'll go with BSP threaded plugs unles someone has a better suggestion.

just looking for someone that has done it successfully.

The 1.5 is still in work, its my winter rabbit.  just a month or so behind schedule.  Still collecting the turbo plumbing.  Manifolds and turbo are on.;  Airbox, turbodrain and what IP to use are the remaing issues.
Title: 1.9 head on a 1.6 mech. block
Post by: Audi80 on December 02, 2006, 09:14:56 am
For metal HG, you will have to block the second return hole from gasket also. I used 2mm rubber for it.
Title: 1.9 head on a 1.6 mech. block
Post by: RabbitJockey on December 02, 2006, 10:11:25 am
run the 1.5 pump, unless you want an lda, but the 1.5 pump will give me revs than a 1.6 pump, should help give it more ass, they are supposedly a little better.
Title: 1.9 head on a 1.6 mech. block
Post by: saurkraut on December 02, 2006, 01:04:01 pm
Yup, going to use a 1.5 pump.  I'd like to put the LDA top on the 1.5 pump, but I haven't gotten around to putting the two pumps side by side and see if it possible to swap the tops.

i emailed Giles but haven't heard back yet.  I guess he is really busy now.  If the tops aren't intercangeable, maybe some of the guts are intercangeable.

Probably have to do a rebuild as every used pump I've put on other diesels has leaked eventually.

I'm really interested to see the results.  I even saved a crank and rods from a 1.5 to put in my 1.6 if things work out.
Title: 1.9 head on a 1.6 mech. block
Post by: 935racer on December 02, 2006, 04:01:50 pm
Maybe I am missing something but you can't mount a hydro head on a mechanical block, what is going to give the lifters pressure?
Title: 1.9 head on a 1.6 mech. block
Post by: burn_your_money on December 02, 2006, 04:11:41 pm
Quote from: "935racer"
Maybe I am missing something but you can't mount a hydro head on a mechanical block, what is going to give the lifters pressure?


Yeah now that you mention it I seem to recall reading that you can use a mech head on a hydro block but not vise-versa
Title: 1.9 head on a 1.6 mech. block
Post by: 935racer on December 02, 2006, 05:20:14 pm
I know you can't, unless these reman heads come with mechanical cam followers, which I highly doubt they do, than its just like a factory head. Hydro heads only go on hydro blocks, Mechanical heads will fit on either.
Title: 1.9 head on a 1.6 mech. block
Post by: RabbitJockey on December 02, 2006, 07:55:12 pm
he doesn't have aftermarket... but the aftermarket one i have will go on either.  i've read here several times that you can put a hydro head on a mechanical block but blocking the drain hole
Title: 1.9 head on a 1.6 mech. block
Post by: 935racer on December 02, 2006, 08:06:07 pm
Quote from: Trev0rbr
he doesn't have aftermarket... but the aftermarket one i have will go on either.  i've read here several times that you can put a hydro head on a mechanical block but blocking the drain hole


How do the lifters get oil pressure and how does it drain back into the block?
Title: 1.9 head on a 1.6 mech. block
Post by: saurkraut on December 02, 2006, 08:19:39 pm
Its a NOS bare head, guides only. I was planning on running solid lifters. Will they fit in the Hydro head?
Title: 1.9 head on a 1.6 mech. block
Post by: RabbitJockey on December 02, 2006, 08:21:27 pm
just so you know i am not arguing in any way or anything, but the drain holes are the same right. theres 3 of them 2 in the back and 1 in the front, then a hydro head has an extra one in the front, thats the one you plug right.  and wouldn't they just get oil through the normal passages?
Title: 1.9 head on a 1.6 mech. block
Post by: saurkraut on December 03, 2006, 05:59:54 am
A lot of stuff flying around here.

Finish this statement:

"It is IMPOSSIBLE to put a hydro head on a mechanical block because....."
Title: 1.9 head on a 1.6 mech. block
Post by: RabbitJockey on December 03, 2006, 07:24:09 am
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
Title: 1.9 head on a 1.6 mech. block
Post by: saurkraut on December 03, 2006, 07:48:25 am
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.
Title: 1.9 head on a 1.6 mech. block
Post by: mk1TD on December 03, 2006, 09:16:27 am
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.
Title: 1.9 head on a 1.6 mech. block
Post by: RabbitJockey on December 03, 2006, 10:45:31 am
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
Title: 1.9 head on a 1.6 mech. block
Post by: saurkraut on December 03, 2006, 12:48:47 pm
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.
Title: 1.9 head on a 1.6 mech. block
Post by: itzdshtz on December 03, 2006, 01:42:21 pm
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.
Title: 1.9 head on a 1.6 mech. block
Post by: RabbitJockey on December 03, 2006, 02:10:46 pm
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
Title: 1.9 head on a 1.6 mech. block
Post by: saurkraut on December 03, 2006, 09:04:44 pm
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.
Title: 1.9 head on a 1.6 mech. block
Post by: saurkraut on December 05, 2006, 08:49:06 am
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.
Title: 1.9 head on a 1.6 mech. block
Post by: saurkraut on December 05, 2006, 02:14:29 pm
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