Author Topic: Converting a 1.9 head to instal on a 1.6 mech. block (Read 50613 times)

saurkraut · « **on:** August 19, 2008, 01:48:31 pm »

Finally got a gap in the car mantenance action, I decided to resurect the 1.9 mechanical head project.

The 1.9 head is a direct bolt on for the 1.6 hydro motors. On mechanical motors, the extra oil drain hole needs to be plugged. As far as hydro vrs mechanical cam/lifters, the hydo set up is easier, and should work on a mechanical block after thera drain hole is plugged. I prefere mecanical lifters, so that will be my focus.

Its going to go on my '79 Rabbit, wich only gets driven in the summer.

The first thing I've done is plug the extra oil drain hole.

A 3/8" aluminum pipe plug is a very good fit:

In goes the 3/8 NPT tap:

Athough i started the process on the kitchen table, the tenacity of the head material lead me to move the program to the shop.

"Tap Magic" does not work on aluminum. It smokes and stinks to high heck and turns to a black goo. Fortunatly, I had some Aluminum Tap Magic and things went better. WD40 is also a good substitute.

As the tap approached full insertion, it took several cycles of getting a turn on the tap, backing it out, cleaning the shavings off the tap and out of the hole, then re-inserting the tap for another turn.

I had to judge the tap depth, vrs the plug thread in/snugness as the plug is tapered. 1 turn below the surface was the ticket.

Here's were the plug got tight:

I bought the plug from McMaster Carr because they delivered to my business address. What I didn't check was the size of the square socket in the back of the plug. Much to my amazemant, it was nither 1/4", 5/16", or even 3/8". I went back to the McMaster web page to pull up the drawing, and low and behold, the drive socket in the back of the plug is 0.31" WTH?

I got a piece of 5/16" key stock and carefully reduced it on my grinder untill it fit:

And here it is all snug and happy:

I just have to debur the hole, and decide what to use for a sealant. I'm thinking locktite, or that hardening gasket shelack.

Next step is the aluminum shims to change the valve spring seat to the right height for the mechanical cam followers.

Here's my super wiz bang drawing for the shims:

The valve seat difference between a mech head and a hydro head is 0.294". Its handy to have a CMM for this measurement. :wink:

All I have to do is push the guides out of the head, put the shims in, press in the new guides, and I'm ready for all the mechanical valve stuff.

While I'm waiting for the shims, I'll do a little port work. I have copies of an old article written by Dave Vizard on do it yourself porting for VW heads. i'll post it if anyone is interested.

riddleyo · « **Reply #1 on:** August 19, 2008, 02:23:31 pm »

Wow, nice project. Yea, go ahead and post up the David Vizard article, it would be a nice read.

saurkraut · « **Reply #2 on:** August 19, 2008, 03:01:03 pm »

The David Vizard porting article:

http://www.vwdiesel.net/forum/index.php?topic=15782.0

gigaz2 · « **Reply #3 on:** August 19, 2008, 03:21:18 pm »

nice work!

I'm interested on the article

really interesting setup, mechanical should be more efficient

EDIT: already printed

now I have something to read on the %&$%

saurkraut · « **Reply #4 on:** August 23, 2008, 12:39:31 pm »

Here is a finished valve spring seat shim, with a guide and spring seat for reference.

Its going to be a couple weeks yet till I get it running. I have to send my exhaust manifold out to get replaned flat.

I think I'll wip out the porting instructions and my Dremel and carve on the head for a while.

RabbitJockey · « **Reply #5 on:** August 23, 2008, 01:06:24 pm »

this is cool, post pictures of it ported

saurkraut · « **Reply #6 on:** September 05, 2008, 01:19:12 pm »

Here's some pictures of my "porting" work. I cleaned out all the casting flaws, and now I'm loosly following the David Vizard article.

I'm using a Dremel tool with a carbide bit that is specifically for aluminum to remove metal. I use the electric drill with a rod and a strip of emery cloth wrapped beyond the end of the rod for smoothing and polishing.

The 3M emery cloth assortment is really handy. Start with the coarsest stuff, and work down to fine.

I remember from my 2 stroke porting days that a satin finnish is better than a mirror finish for max airflow, so don't go nutz. Just smooth it up.

I'll try to get better pictures, but my illumination options in my basement are somewhat limited.

Hopefully, I'll be pressing in new guides with my valve seat shims this week end.

gigaz2 · « **Reply #7 on:** September 09, 2008, 08:43:49 pm »

does the mech cam clear the head?

saurkraut · « **Reply #8 on:** September 16, 2008, 10:00:55 am »

I measured the stuff on the top of the head with a vernier caliper when I first received the head. Best of my recolection, all the dimensions on top are the same, except the spring seat height.

PROGRESS: I pushed out the guides, put in my .294" shims, and pressed in new guides.

One thing I've noticed, that I didn't notice befor; the valve pocket area of the port is 'lower' in the Hydro head. The giudes are the same, the valve seat area is lower, so the valve pocket has to be lower, by .294" i would imagin.

This makes porting easier, as the guide used to protrude, but now is up slightly into the head. So now I can take out a large part of the valve stem hump with out having to dodge the valve guide.

I think after I finish porting, I'll send the head out to be plained. This will make sure the pipe plug is flush to the head. I might even fill the socket with devcon befor send it out to be plained.

I'll try to post some pictures of this soon.

VW Smokr · « **Reply #9 on:** September 16, 2008, 12:49:06 pm »

saurkraut, that's a bunch of conversion work. Hate to sound stupid, but is your project goal to produce gains in horsepower, torque, fuel economy, lower emissions, or what? (I know; sounds like a newb.)

Don't the 1.6L mechanical heads have a water passage right where you put the aluminum pipe plug? Seems like all coolant flow is critical on our VW diesels, but maybe I'm just missing something basic here.(?)

Won't you also have to use a 1.9L intake manifold, or modify the 1.6L unit?

Interesting work, and nicely done.

J.R.

zukgod1 · « **Reply #10 on:** September 16, 2008, 01:20:15 pm »

That hole he blocked off is just a extra oil drain. Not needed.

saurkraut · « **Reply #11 on:** September 16, 2008, 02:51:37 pm »

Quote from: VW Smokr

saurkraut, that's a bunch of conversion work. Hate to sound stupid, but is your project goal to produce gains in horsepower, torque, fuel economy, lower emissions, or what? (I know; sounds like a newb.)

Don't the 1.6L mechanical heads have a water passage right where you put the aluminum pipe plug? Seems like all coolant flow is critical on our VW diesels, but maybe I'm just missing something basic here.(?)

Won't you also have to use a 1.9L intake manifold, or modify the 1.6L unit?

Interesting work, and nicely done.

J.R.

The 1.9 head has bigger ports, and bigger swirl chambers which should lower my CR to 19:1 or somthing around there. I have an Excel spread sheet that has CRs for different heads on different motors somewhere, but 19:1 is in the ball park.

I don't like hydralic lifters.

I should be able to pack more air in each stroke.

The lower compression should reduce stress on the rods.

Therefore, I should be able to run a more stupid booste level with more fuel and have less chance of busting anything in the engine.

I suspect I'll lunch another trany next though.

I have been running a K24 at 25 - 30 PSI with some smoke. Crapped a piece of a turbine blade out the tail pipe once. I have a k-26 that I plan on grafting its kompressor on to the k24 and get even more air in there.

Yes, I have the 1.9 intake manifold too.

After I finish this monkey business, its back to the 1.5TD program.

I'm just a shareing kind of person....

saurkraut · « **Reply #12 on:** September 22, 2008, 01:52:44 pm »

Pictures!

Here is the new guides and the .394" shims installed.

On the port side, the guide is now slightly into the head. Which means the hump for the valve guide can be wittled down quite a bit.

Here is a port after roughing. It looks much rougher than it really is. The wonders of photography. Nice big hole.

Its really neat how this worked out in the valve pocket. The valve hump is almost gone. I kept the 'bias' of the original port, as advised in the Vizard article. It didn't take alot of work either. The port almost maintaines it's full diameter through the valve guide area. This may be even a better reason to turn a Hydro head mechanical.

Smoothing is next, then a head shave, then valves/cam, and on to the 1.6.

kane66 · « **Reply #13 on:** September 22, 2008, 09:34:52 pm »

How hard do you think the start will be with the lower compression. Also I heard that reducing the compression increases MPG's, do you know if thats true.

saurkraut · « **Reply #14 on:** September 23, 2008, 09:24:31 am »

Someone already did put a 1.9 hydro head on a fresh hydro block and had OK starts, even in cold weather.

There was someone else that put one on a bagged out block, and the starts were butt ugly. But it ran good with more power when it was warm.

It may not be the hot set up for below zero starts, or hipermileing.

I'm not really concerned with the fuel milage. I'll make sure I get the right head gasket thickness so the squish and swirl are good, which should make a good burn off boost, and should make OK milage. This more of a quest for more power with out bending rods.