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MFX

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Don't stress it mate. Lucky the piston did not fit in the barrel !!!

I recall my first build, I managed to do the same and the piston made it in the cylinder. Once in the car, I couldn't understand why the smoke out of the exhaust until I pulled the heads off......?

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On 6/15/2018 at 3:34 PM, P-Kay said:

Don't stress it mate. Lucky the piston did not fit in the barrel !!!

I recall my first build, I managed to do the same and the piston made it in the cylinder. Once in the car, I couldn't understand why the smoke out of the exhaust until I pulled the heads off......?

That doesn't sound like fun at all! I will admit that putting the pistons into the cylinders was the most stressful part of the whole week. The oil rings are so small that any slight gap with the ring clamp and it would pop out. What kills me is that we had them all in, and then I realised I somehow got some of the pistons in the wrong cylinders. If I hadn't made that mistake, it would have been fine.

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33 minutes ago, MFX said:

That doesn't sound like fun at all! I will admit that putting the pistons into the cylinders was the most stressful part of the whole week. The oil rings are so small that any slight gap with the ring clamp and it would pop out. What kills me is that we had them all in, and then I realised I somehow got some of the pistons in the wrong cylinders. If I hadn't made that mistake, it would have been fine.

Texta markings  are better than memory.

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Watching your vid, I was quite surprised you put the pistons not in their respective chosen cylinders. Especially with all of the documenting you did! Like Steve says, I now mark everything with texts - even though the rods are numbered. Even my last build, I had a few challenges with the oil rings - so I can relate ;)

As far as my first build, that was nearly 30 years ago, so replacements were nothing like they cost now!! 

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On 6/17/2018 at 6:44 PM, P-Kay said:

Watching your vid, I was quite surprised you put the pistons not in their respective chosen cylinders. Especially with all of the documenting you did! Like Steve says, I now mark everything with texts - even though the rods are numbered. Even my last build, I had a few challenges with the oil rings - so I can relate ;)

As far as my first build, that was nearly 30 years ago, so replacements were nothing like they cost now!! 

I marked everything, but my notes were slightly confusing, when cylinder #3 goes with piston #1, and will end up on the engine as Cylinder #4. I am not sure how I stuffed it up, when we were doing it, but that is why everything is triple checked, and we fixed the problem. 

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Re: build part 4

Hi Jeff,, was wondering if you'd contacted Porsche about their new bearing part and the notch on the wrong side to where your groove is. Seems incredible they could get it so wrong.... If so, any feedback? Has anyone contacted you experiencing a similar problem...?

 

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5 hours ago, ber911 said:

The 911 crankshaft bearing shell part number changed sometime in '75 apparently for all models from 901-101-132-00 to 911-101-133-00.

The only difference was that the tang changed from one side to the other.

 

Rob

 

Interesting. That may well be the issue. Strange that they would change the side of the tang mid engine run. You would think if they were going to do that it would be done with the 3.0.

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Hi Jeff,

Looks like you had an interesting week ?

A couple of questions/comments:

  • I know you're not strictly speaking building a race engine, but I'm curious as to why you wouldn't go the extra mile and eyebrow cut the barrels, open the case for windage and knife-edge the crank?  This has been somewhat controversial among some engine builders in the past, but I recall talking with Klaus Bishoff at Targa one year and he was quite adamant that the factory saw worthwhile gains (10+ hp) doing this.
  • I know shops develop their own techniques, but personally I've found it easier to insert pistons in the bottom of the cylinders and of course there is often no 'right' way to do a particular thing but I'm curious to know why Neil favours from the top?
  •  I recall comments on blogs re the bearing tangs going back quite a while.  The bigger issue is bearing quality - particularly from Glyco.  I recall a few years back that engine builders often had to go through several sets to get one good set.  Probably fixed by now but curious to hear Neil's experience.
  • Do you know when they are going to make the oil-pump internals available?
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5 minutes ago, bumble said:

Hi Jeff,

Looks like you had an interesting week ?

A couple of questions/comments:

  • I know you're not strictly speaking building a race engine, but I'm curious as to why you wouldn't go the extra mile and eyebrow cut the barrels, open the case for windage and knife-edge the crank?  This has been somewhat controversial among some engine builders in the past, but I recall talking with Klaus Bishoff at Targa one year and he was quite adamant that the factory saw worthwhile gains (10+ hp) doing this.
  • I know shops develop their own techniques, but personally I've found it easier to insert pistons in the bottom of the cylinders and of course there is often no 'right' way to do a particular thing but I'm curious to know why Neil favours from the top?
  •  I recall comments on blogs re the bearing tangs going back quite a while.  The bigger issue is bearing quality - particularly from Glyco.  I recall a few years back that engine builders often had to go through several sets to get one good set.  Probably fixed by now but curious to hear Neil's experience.
  • Do you know when they are going to make the oil-pump internals available?

Hi Mark,

Neil talked about knife edging the crank last time I was there, and he was of the opinion that it was a waste of time. He went into his reasoning in quite some detail, but I can't remember the arguments off the top of my head.

I think It may be easier from the bottom in this case. Neil actually made up a sleeve (looks like an Aluminium Donut, with a taper which was the exact size, as he hates the ring clamps, but it was too tight, which he thought was odd, after he opened it up just a touch it was too loose. It ended up that it was too tight because of me overlapping the compression ring. 

Not sure about the bearing quality issues, but I do know that some of my bearings were genuine Porsche items and some were Glyco, so not sure. 

As for the pump internals, they ended up not working for these pumps as the splines are too close together. They work on bigger pumps and look a bit like a figure 8, but due to how close together the splines are and the dimensions of the pump internals, the 8's were so small that they didn't pump even as much as the factory ones. He is still looking at more development on them, but the original plan didn't work on these.

It was quite interesting when I talked to him about the new Williams Singer engine and some of the issues they are having with the 4 valve heads. He showed me a couple of aircooled 4 valve heads he had on a shelf that he had developed for the 962's and back then they had similar issues.

Jeff

 

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  • 5 months later...
56 minutes ago, OZ930 said:

So, where are we up to on this project ??

Same as before :(  Still waiting on the engine. There were some things to sort out when I left, as the custom pistons were interfering with the valves, so they had to be re-machined and recoated, which has been done. The replacement rings have come back from Mahle and the last thing I am waiting on is the shafts for the ITB's. Neil gave me some old ITB bodies he had kicking around for the last 20 years on the shelf. I bought the butterflies and all of the rest of the bits for them, but the company no longer makes the shafts, so Neil has been fabricating them. He has just had a couple of issues as the first 2 didn't go as planned. He is packing the engine up at the moment to send it back, so hopefully it will be on its way soon.

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  • 1 month later...
  • 2 weeks later...

Not trying to cause any embarrassment here, but keep asking myself "why would you go to the USA when there are many great engine builders in Australia".  I am also concerned that this engine is going to have a higher compression ratio than is needed for a road car. Anyway wishing that this turns out all good for Jeff and that it turns up soon.

Paul M

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6 hours ago, Coastr said:

I think he was invited to do the machining in that shop and have a go.  Pretty sure Jeff is still ‘the builder’ and he is waiting on parts, not someone to put it together.

That is basically spot on ;) 

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There are going to be different answers to this question, but I'm thinking old era and carbs here and Porsche set compression ratios for reliability and world-wide distribution. I haven't seen whether Jeff will use carbs or fuel injection.  Jeff is estimating about 11.34:1 compression ratio and dependent on tuning I'd say he will have to run 98 octane or better. (In the "old days" 10:1 gave good horsepower.  and we often used 100 race or aviation fuels or added methyl benzine to pump fuels, but this is last century stuff). Sure Jeff has given this much thought in his careful calculations. BP Ultimate is the go IMHO.

 Open to other opinions.

Cheers

Paul M

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