The eternal rebuild

[richie]

Nice write up Pete, sucks it happened, going to put my money on a lifter failure, they don't like sitting on limiter for long, am actually surprised you got it set so low? was thinking it would be up around 11k for hard limiter

cheers Richie

[brewsy]

Desmodromic for the win 😁👍

Now THATS an idea..
4x Ducati heads??

The 851/916 both had 94mm bores and the 4 valve Ducks had a decent cylinder head design (rather than the 2 valve hemisphericals).
Only problems I see would be a) getting them to fit b) adding water cooling to all 4 and getting them to seal on the barrels c) getting drive belts to run them and d) passing drive through one head to the other (unless JP used 4 belts?)..
Apart from that it sounds like a right easy job 

Would sound AMAZING Im sure

[Peter Shattock]

Brewsy

No drama re the engine. As I said, the reality is I’ve been very lucky that it happened when it did. I don’t like to think what it might have done at 9,700rpm at the end of the track!

The cooling is a little something I’d been working on since the original plan was made to make a 10,000 rpm efi street engine. I was told you have to have at least 12v to keep all the electrical stuff happy so wanted to run with the fan belt and a decent alternator. I obviously didn’t want the losses of running the fan on the end of the alternator shaft though.

The last time I raced at EBI this was highlighted when I struggled to get into the 11’s with the fan belt on with the old engine and ran mid 11’s when I took it off. I knew there was no way I could afford to give away 0.5 of a second and it was only going to get worse when you consider I was  planning on running with around an extra 2,000rpm!

You may know some modern cars decouple various belt driven non critical ancillaries when the ecu detects full throttle. This got me thinking if I could do this with the fan.

What I have done is not that sophisticated, but allows me to switch the cooling fan on and off when I want with a switch.

In basic terms there is an electromagnetic clutch like the ones you see on air conditioning pumps on the end of the alternator shaft that either runs the fan or lets it free spin on a bearing when it’s not required.

It all sounds simple, but it actually proved to be a serious pain in the backside to get it packaged as there is not a lot of room, but it’s great now it works. What I really wanted was something you can’t see and as no one has noticed it to date that appears to have been a success. Perhaps if I hadn’t written it here maybe no one would have noticed as the only visible clue is a wire coming out of the alternator back plate and off round the back of the fan shroud.

The problem is alternator alone costs a small fortune now (I bought mine years ago) and with the clutch on it I suspect it’s about the most expensive ACVW alternator known to man! That is nothing to be proud of, but all I can say is if there is anyone else stupid enough to want to do it good luck!

Here’s a picture. Don’t shoot me as I have already been lambasted about the alternator strap by the fashion police so holes like the old one on the 1795 engine and a ti nut and bolt are on the way and yes the nut and both will be at the bottom.

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Plan C is simple new cam and pistons. The main issue being the cam as you suggest, but the cam in the motor now is the original one which we lost control of at about 8,500 rpm. We now have lighter pushrods and more spring pressure so the engine is good for 10,000 rpm with the same cam. As it turns out neither this cam or the subsequent one is quite where it needs to be, but we have now hopefully proved that the lighter pushrods and new springs have survived, which gives us a bigger safe operating window to design a cam within which is closer to optimum than either of the two we have tried to date. That said what I have come to realise is that actually getting it right where it needs to be is all but impossible. We are hopefully learning though and getting closer to the ideal cam with what we now know about the two tried to date.

I’m certainly looking forward to cam number 3 though, but don’t be surprised if there is a 4th.

Vwhelmot, no fancy valve train configuration changes coming for me.

For some inadequately explained reason I like keeping it just as VW intended with just a bit of a twist

Peter

[Peter Shattock]

Hi Richie,

I hope it’s not a lifter for various reasons, but not least of all as if broken bits of ceramic lifter go for a dance round your engine it makes a real mess of most of it! The single cylinder motor tells that tale unfortunately...... we’ll see, but I hope you’re wrong!

P

[Peter Shattock]

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What’s going on in there then....

[Peter Shattock]

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The end result

[Peter Shattock]

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Caught up with Martin and all things NSU during the long wait in the fire up lane.

[leec]

Did you get him to decide on a colour  

Lee

[DaveN]

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Caught up with Martin and all things NSU during the long wait in the fire up lane.

Sounds like a form of torture

[richie]

No wonder it broke    Was thinking some more and reckon you would have seen something in valve train if lifter broke badly so maybe not that

[Eddie DVK]

Man, that fan solution is ingenious.

[alex d]

The clutched fan is brilliant, thought about something along those lines many times but never really figured out how to package it, great work!

[Peter Shattock]

Poor old Martin.... no colour, I just told him to put it together and use it! It did save me doing a Big Pete and falling asleep though, good point about the breakage though, in the absence of anyone else to blame it does make good sense to blame him!

Alex / Eddie, it’s a good solution if a bit heavy for the weight conscious. You could even use it as an F1 style overtake mode on the street if you come across a particularly troublesome ricer.

I do wonder if I might not have been better off running a bigger battery and whip the belt off at the start line and save some weight on the car and kept it in my wallet, but it’s done now.

Peter

[dangerous]

https://www.youtube.com/watch?v=K8E_zMLCRNg

[dangerous]

What is the latest Pete? I am sure I am not alone in anticipation!! 
 

[Peter Shattock]

So it’s been a while, but the long overdue update is that the gearbox has been rebuilt and it and the rear suspension are back in the car.

2nd gear had some misplaced teeth, it needed some new dog rings, new R&P was precautionary plus some bearings and seals.

Who knows perhaps the car might even make it to the track this year.

Peter

[henk]

You better make it to the track this year and give us some updates.will not be much else to do otherwise i think.

Henk!!!

[dangerous]

What noise-cause did you find in the engine Pete?

[Peter Shattock]

Sorry another big gap between updates but first a trip back in time, in fact right back to the beginning for me with this car.

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So the noise was a bit of valve guide which dropped into the cylinder but not the one it came from which is a bit odd but it shows what’s possible all be it not obvious. Given it was caught quickly and not under load I got lucky with little damage. I was planning new pistons anyway and the head will repair so given how bad it sounded the outcome was not nearly as bad as it might have been.

Hope to make some more positive plans subject to what Covid 19 has to say about it.

Stay safe all. P

[leec]

Hi Pete,
Hope you are well.
Glad the damage wasn’t too bad. I am guessing that’s also a very early pic of All Torque in the garage?

Lee

[Peter Shattock]

Your not wrong Lee. That was right towards the end of my time with the oval. I bought it in 1987-88 ish and that photo must have been around 1999. I think Matt bought it in 2000-01. Not sure where it is now, I’ve still got the original ignition key and wanted to give it to the current owner at some point, not that it will be a lot of use in the wild state it’s in now!

[leec]

I assume Nick Edwards still owns it? Only remember his name as an old assistant manager of mine had the same name!

[jamiep_jamiep]

Great to see these pics of it when it was a stock 'as found' car Peter

[numbnuts]

I really enjoyed reading this thread Peter, thanks for taking the time to do the write up and sharing your journey. It's great to see someone thinking out of the box with these old cars and the quality of the work looks outstanding.
I hope you manage to get out this year and put some miles on it 

[Peter Shattock]

So it really has been a long time since the last update. There are plenty of dull excuses which are not interesting so here’s the next instalment of more positive news.

Quick recap.
The motor went off for a holiday in Sweden back at the end of 2019 to check out the nasty noise at the last event I did in 2019, as well as a freshen up and a few planned modifications.

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Every front room needs one.

[Peter Shattock]

This was timed so I could also re build the old small and damp single garage that the car had been living in for the last 20 years. With the motor away the car had a more local holiday in a mates garage, whilst the old garage was demolished and the new shiny one built.
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The building work for the garage got completed at the end of winter 2020 just in time for COVID to get in the way, but the car was back home and in the garage just before lockdown.

[Peter Shattock]

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[Peter Shattock]

Fast forward to September 2020 and the gearbox was apart to check out the noisy second gear. The problem turned out to be an obvious one.
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[Peter Shattock]

Following a new 2nd gear and a general freshen up and a precautionary ring and pinion the box was back in the car in January 2021.
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[Peter Shattock]

November 2021 Johannes had the motor unpacked and apart and found the offending bit of valve guide Sat in the cylinder which made the understandably nasty noise.

There was also a piston which had picked up and the exhaust valve keeper groves were not what you would want either.
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