Finally running (sort of)!

[XR8tt]

Be interesting what clearance they set ??
C.P's are .0035 .. Over .0040 you start loosing power unless its a big bore motor..

Rattle when cold in typical forged piston...

 

[Zuffen]

I'm about to start a re-build.

I'll keep my heads, crank, rods and pistons.

The rest is being junked.

The block is beyond redemption as it was overbored when it was last built. The clearances are around 15thou!!

I'm going to dismantle the block and be with the engine builder every step of the way until its all together.

I'll also strip and re-build the supercharger.

Concesus is the engien was running way rich and when added to the oil coming from the supercharger the octane rating was pretty average.

No sign of detonation but combustion pressures must have been enormous.

The broken cam drive caused unburn fuel to wash the bores and fill the sump which diluted the oil suficiently to cause some oil pressure problems so we can sort that out this time around.

I'll probably have the engine builder tune the engine this way should anything go wrong he will have been there every step of the way and can assume some responsibility for whatever happens.

Later Yavuz can have alook at it.

The engine builder will be working at a discounted rate (plus he'll have me as an unpaid apprentice) so I hpe to have it all back together for around $3,000.00.

Now all I need to do is decide what I'll do about intercooling the beast.

Basically a lot of errors has caused the poor thing to yell enough.

 

[Zuffen]

Here is aphoto of the head gasket. The clean spot is where it failed. No bits blown out of it.

Additional photos show the state of the inlet manifold where its covered in oil residue.

 

[cribbj]

Ughhhh, I feel your pain Rod.....

Make sure the builder, or someone you trust implicitly, examines the ring lands on your pistons, particularly #1 that blew. There could be microscopic cracks in them. I'd have a close look at them under a low power (maybe 50x) microscope, and/or use a fluorescent dye penetrant on them to magnify the existence of any cracks.

There's a number of educational type digital microscopes available for around $100 that'll connect to a PC (have a look on Amazon for digital microscope). One of these and that black light you've had in your attic since the 60's, ought to be just the ticket for doing this.

 

[Cobber]

How hot did that charger / manifold get.....?

The supercharger only holds a small amount of oil to start with (100 - 150 mls) so I don't think it would have had a big impact on the overall fuel octane unless it dumped it all at once.

It looks more like a accumulative build up as the supercharger manifold switches from vacuum to pressure pumping oil out past the seals into the manifold.

Interesting to see the air flow path of the supercharger too.

 

[JustenGT8]

Bloody hell 15 thou??? that's twice what is needed even with low silicon forgies? Why did the builder go with so much?

Same builder this time? I think you have good recourse for a free rebuild given this is an arror you can measure and is beyond dispute?

Hard to pick much from the gasket in the pic but it doesn't look to have seated as well as the rest? Did you check the head stud torque when you undid them? doesn't look to have been torqued properly at that end?

What a bitch

Good to hear you are having another crack at it though

 

[Zuffen]

Fuel wash and the resultant oil dilution took the main bearings out. That explains the slow oil pressure on start up.

The crank is fine and Ed Oates is providing a block (gratis) to the cause.

Thanks Ed.

 

[-Nemesis-]

Good to see you're having another crack Rod!

 

[Zuffen]

A quick update.

I've worked at the engine builders the last 4 days and we're now honing the bores. So far we spent 4 hours today on 4 cylinders! We expect to have another go at them tomorrow once the block has cooled.

We expect to finish the honing Monday as it will be too hot tomorrow (the block not the weather) to finish it.

We had to hone 5thou from the bores which is too little to bore and a lot to hone out. At least the bores will be straight and nicely honed. We're finishing off with 500 stones and it will be within 0.1thou of what we want.

It turns out I'll do most of the labour, and learn to use a heap of fun machines I'l probably never use again.

I was offered a job on Monday by the shop, so I must be doing OK.

I was asked to solve a problem on an engine conversion this afternoon which is sort of funny. Easy problem to solve and it will be sorted tomorrow.

We're going to use a new valve seat profile that is giving great results on US V8's.

I would expect I'll be at the shop for another 2-3 weeks and to put in around 100 hours on the engine plus the time the shop owner puts into it.

Hopefully this time around it will do everything we want it to.

I don't blame the shop for the problem as there was a long list of problems with parts, work done by a few suppliers and a less then perfect tune.

 

[JustenGT8]

good to hear it's sorting itself out....who knows, a new career Rod as a UZ rebuild specialist

 

[XR8tt]

This reminds me of Love the Beast movie..
When he built his own car he didn,t hurt it..
But when pro's built his car he crashed..
There's more soal in it when you do it yourself !!
http://www.lovethebeast.com.au/

 

[edz]

It turns out I'll do most of the labour, and learn to use a heap of fun machines I'l probably never use again.

I always say, if you do it yourself, at least you know it's done right ( and if not, you've only got yourself to blame!).

Good effort Rod, sounds a little..................boring.............. ;-)

 

[Zuffen]

Further update.

The engine is now totaly stripped as I did the heads on Friday.

The rings are knackered due to the detonation but the pistons are unscathed. Looks like buying the Ross pistons was the right move.

I have a set of rings on order from Ross with a 48 shipping timeframe. They don't stock them but will make them and ship in 48 hours. Pretty cool.

We've ordered new standard sized main & big end bearings.

The heads will go into the CNC machine for new valve seat profiles as the shop thinks they could be better this time around.

We're also going to hand finish the pistons by radiusing any sharp edges to combat detonation.

We're machining washers to go under the spark plugs to stop any exposed threads in the combustion chamber which could lead to detonation.

In an attempt to lower piston temps we're installing oil jets courtesy of Lextreme.

The inlet manifold is in for more porting as we've identified a couple of areas where it could be more efficient.

Lastly we're building a new section for the manifold to allow us to extract the supercharger's output and send it through a 1500cfm water to air intercooler than into the back of the manifold which should improve distribution over the existing set up.

The oil entering the charger has been traced to running a breather on the snout (so we'll block that off) and the throttle blade closing too well when you back off. By allowing a 5thou gap on the throttle blade it will stop the sharp vacuum on overrun which caused the supercharger to suck the oil out of the gearbox before the by-pass valve could open. This save me rebuilding the supercharger as I thought it had blown seals.

All in all we're looking at a huge drop in intake temps and a noticable increase in air flow capacity.

All that should translate into a little less boost but a lot cooler boost which should net us more horsepower for less stress on the engine.

We finished honing the new block to 2.5thou clearance yesterday. It took 3 days to hone the block as we had to keep letting it cool down, which caused the clearances to close up before we could finish it to the correct size. This means the piston/cylinder clearance is now 1/9th of what it was!

Lastly thanks to Ed, ed_ma61 who gave me a stock bore block to work with. Yes gave me as in free. That's what Forums are about.

 

[Cobber]

Well done Rod,

Don't forget to post the pics of the re build.
I'm interested in the manifold porting your going to do as well. I am in the process of re doing my supercharger set up as well so it's time to get the die grinder out again.

 

[cribbj]

Rod, it sounds like a solid plan you have there.

Are you going to do anything to reinforce the drive/shear pin between the intake cams and the drive sprockets? As you know, your pin shearing wasn't the first time it's happened.

Interesting point about that breather/vent. As you know, I plugged that port before I ran my supercharger, mainly because I inadvertently had my snout turned 180 degrees from yours and thought it was a drain!

 

[Zuffen]

Cobber

I'll post up pics as we go.

John,

I plan on adding an extra pin to each drive. Easy enough when its apart.

The breather problem with the Autorotor is interesting and the solution makes sense. At least that's one less hose in the engine bay.

 

[scotturnot]

The oil entering the charger has been traced to running a breather on the snout (so we'll block that off) and the throttle blade closing too well when you back off. By allowing a 5thou gap on the throttle blade it will stop the sharp vacuum on overrun which caused the supercharger to suck the oil out of the gearbox before the by-pass valve could open. This save me rebuilding the supercharger as I thought it had blown seals.

Could you give me a little more info on this? Maybe a picture, I dont want to make the same mistake.

 

[Zuffen]

Scott,

A little information on the layout of the Autorotor.

The snout is linked directly to the gearbox (it maintians the rotors relationship with each other) without any oil seals so it will leak oil if not used as a breather or sealed up.

The hole has a 1/4" BSP tapped thread in it.

If you read Corky Bell's book "Supercharged" it has photos of Autorotors with breathers attached. I followed the photos and did so. John C blocked his off.

By having the snout open to the atmoshere it allowed the vacuum in the manifold to draw the oil out of the gearbox and into the rotors. From there into the engine was a short trip.

The fix is to have a 5thou air gap on the throttle blade and block the hole off. This stops the sharp vacuum when the throttle snaps shut.

I think a smarter fix is to have a very small bleed into the manifold after the t/b that runs bach to the air filter. This would mean if you (or someone else) inadvertantly adjusted the throttle plate and closed up the air gap you would still have the air gap.

I think a small 1/8 hose from one side of the throttle to the other would most likely do the job. You could experiment to see what the largest port size you could run but still allow the ISCV to do its job. I'll probably start with a 1/4" hose and see how it goes and keep reducing it until it will idle.

 

[XR8tt]

I would have thought all that would be sorted through the idle speed control ?? Where injectors stay in idle mode but ISC opens to prevent too much vacuum.. It also helps with emissions, as used on most std ECU's..
ISC can be programed to open at higher rpm also where high vacuum is present..

 

[Zuffen]

Assuming you can program the ECU to do this it all makes sense.

I question if many "tuners" bother beyond getting the thing to run at WOT!!

What I'm after is a nice drivable vehicle that can sit in traffic or tear up the dragstrip. I don't want one or the other I want bath.

I feel the best bet is to ensure it is set mechanically then let the ECU work around it.

You see I'm old and I can understand shafts and gears but smoke in wires has me beaten.