Engine rebuild, The reassembly started ! Options

[Valy]

Oil Pressure Regulator

I had a different thread on this topic on the 914club site. Thanks to Chris and the Dr for helping out.

My case has a single oil pressure relieve and I used a higher volume oil pump. The pump is capable to create higher oil pressure if not properly regulated and since my case only has one regulator I had to pay special attention to this issue. I wanted to make sure I don't blow away the oil filter, galley plugs or gaskets.

The dilemma was to find the right spring for the job. I had 2 springs from 2 different cores with different and noticeable compression constants.

So here we go:
The sump groove starts 14.5mm below the valve top position.
The springs are pre-compressed inside the cylinder by about 15mm.
The groove depth is 5mm so when the valve piston is 5mm below the grove start, the maximal bypass opening is achieved. Total spring compression for maximum opening is about 35mm.
Max desired oil pressure 80-100PSI before the gaskets or cooler will blow off.
Valve diameter is 16mm. That makes its area 0.31 Sq. inch so the force on the valve at 80PSI will be 25lb.

I need a spring with a compression constant of below 35mm/25lb=1.4[mm/lb] (yes I know that I'm mixing measuring systems but I'm still OK (IMG:style_emoticons/default/smile.gif) )

So I grab the spring in my caliper and sit the caliper on it head on the table. I stand on the same old bathroom scale I used for the torque wrench calibration and compress the spring in the caliper using my weight. I note the compression and the weight applied delta for different weights for both springs.

Compression constants (k):
Spring #1: 1.32 mm/lb
Spring #2: 2.07 mm/lb

The max pressure regulated by those springs:
(max travel/k)/valve area

Spring #1: 35/1.32/0.31=85.5 PSI
Spring #2: 35/2.07/0.31=54.5 PSI - this is too low.

I'll use spring #1.

[Valy]

Half Case Assembly

Mounted the distributor gear with the special oiling washer and the dizzy into the case.
Installed the six through bolts with their plastic centering spacers.
Then cleaned, installed and lubed the split bearing.
I cleaned, lubed and installed the other bearings on the crankshaft and installed the crank into the case.
The bearings aligned quite easy. The smaller one was more stubborn but finality went in.

Similar process for the camshaft:
Cleaned and installed the camshaft bearings, lubed them with assembly grease, lubed the cam lobes with the very thick grease supplied with it and then installed it into the case.

[0396]

Sub... keep it coming., Great write up

[Valy]

Windage/Baffle Plate

My core engine came without a windage plate so I sourced a good used one with its own oil pickup tube. It turned out to be very nice after a good cleaning.


I replaced the o-ring on the tube, oiled it a bit and tried to fit it into the case. No matter how hard I tried, the tube didn't go in all the way. I started to suspect that something is wrong and pulled it out to take a look.

Turns out that there are 2 different dimensions of pickup tubes, fitting different cases.
The tube that came in the case is above and the tube that came with the windage plate is below (note the hole in the cup for the bolt holding the plate)


After I noticed this, I drilled a hole in my old pickup tube to use it with the windage plate and fitted the tube in the case.
One more problem solved. (IMG:style_emoticons/default/piratenanner.gif)

[Valy]

Closing the Case

With the windage plate, cam bearings and main bearing installed, I finally got to the stage where I can reunite the to case halfs!
I used sealer on the matting surfaces and around the big 6 bolts. I made sure all the passages to the bolt holes are sealed and also used sealant on the washers.

Then I closed the case and torqued all the bolts. There are 26 bolts: 6 big M10 ones, 18 M8 and 2 M6 at the oil breather.

[Valy]

Type 1 Oil Pump Installation

I've been through the modifications I made to the Type 1 oil pump in a previous post.

The Type 1 oil pump is a bit thicker than the original type 4 pump. Therefore, the M8 studs that hold it in the case are a bit too short.
I almost replaced them but then I measured them and realized that I can just unscrew them a bit from the case and they will fit. The remaining length inside the case is sufficient to hold the pump (needs to be over 7 threads or 8.125mm since it's an aluminum case)

I fitted the pump case with the thick gasket I made and sealant, then I installed the driving gear and the idle gear and finally the cover with more sealant.

[Valy]

Oil Temp Sensor

I didn't like the oil temp sensor that this motor was fitted with. It was too much exposed to the air so the reading would be inaccurate.

I sourced a proper taco plate and sensor but I was missing the rubber gourmet and new ones are NLA.

I made my own out of a 3/8" rubber gourmet and a 3/8" green screw cap glued together (the glue is just an overkill).
I like that the cap color matches the wire color (IMG:style_emoticons/default/smile.gif)

I also added some sealant between the 2 plates around the holes to help the gasket. That place looks like prone to leak.

[Valy]

Deck Height

I set-up my dial meter to find TDC and to measure deck height.
After finding the TDC, I calibrated the dial meter on the piston and measured the cylinder height.

The picture shows my deck height of 0.048".

I also measured the valves recession into the piston --> 2.1cc (sorry, no picture)

[Valy]

Thermostat

Slow progress this weekend as I was busy driving (IMG:style_emoticons/default/driving.gif)

I got good used thermostat but everything looked like hell. Bracket was rusted all over.
I cleaned and repainted the thermostat bracket and wheel.

[Valy]

Fixing Broken a Tin Screw Hole

Some PO of this engine broke a tin screw in the block. I had been drilled out but I was left with a big hole and no screw to fit in it. I was able to tap the hole to M8x1.0 (fine thread) but being a bit too anal I had to go the extra mile and repair the original thread.

I took an 5/16 aluminum tube and threaded the outside to M8x1.0 and the inside to M6x1.0. After few tries, I got the threads synchronized for maximum strength.



Then I used my high-tech insertion tool (bolt and nut) to insert the insert with some thread lock into its hole.



And the result: that M8x1.0 turned into M6x1.0 (IMG:style_emoticons/default/piratenanner.gif)

[Dave_Darling]

That looks like it's near where the M8 hole is anyway. There's one that is; I don't remember why though.

--DD

[Valy]

That looks like it's near where the M8 hole is anyway. There's one that is; I don't remember why though.

--DD

Dave,
Are you having fun?
They are all M6

[McMark]

Nope. Dave's right... About later cases. Early ones have all M6.

[Valy]

Nope. Dave's right... About later cases. Early ones have all M6.

So maybe you know what goes in here?
The other 2 cases I have are all M6 and I can't find anything that bolts into that fine thread M8.

[McMark]

The thermo-time switch was moved towards the flywheel on later cars. On 1.7 engines (IIRC) the TTS was on one of the M8 case parting line bolts. On 2.0 engines (73&74) the TTS is on the air plenum. On 1.8 engines (and possible later 2.0s) the TTS is on a bracket on the rear tin screw we're talking about bolted with an M8, but I thought it was M8x1.25.

Since yours is a bus case, and it doesn't look like it has the second oil relief piston, I would say that case was an L-Jet T4 bus and the hole was original (I suspect the early carb'd T4 busses would have M6).

[McMark]

Here's a picture of the TTS in place on a 912E, but after thinking about it some more, I suspect this M8 x 1.00 hole (I checked another case here, and you're right) was on all engines that were destined for L-Jet.

[Valy]

Maybe it's a bus thing. I just double checked again and my 1974 1.8 914 only has a M6 screw there (IMG:style_emoticons/default/confused24.gif)

[euro911]

I've got a '75 GC case here that has the M8.

Hope you didn't use RED loctite (IMG:style_emoticons/default/sad.gif)

[Valy]

I'm not planning to take the insert out. The L-Jet that I have and intend to mount on it doesn't need that hole so I'm happy with it like this.
And even if I want to take it out, I can.
I was just wandering about the use of that hole as I never found anything M8x1 to fit into it and all other cases I have are all around M6.

[McMark]

If you're running L-Jet, are you leaving off the thermo-time switch?