Shoptalkforums.com

Wow, that sucks. I always thought the Deutz ones were the stongest, with the thickest wall, but its insane what knock can do! Luckily you guys got it fixed quickly again.

Ps. Still curious what time you drove on 3 healthy cylinders.

Mark

My thoughts the same as Mark above. I always thought that the Duetz cylinders were the beefiest one could get. This just goes to show the damage a slight case of knock can do!

Thanks for the update Wally!

As ever Wally, very impressive.

Not that I know anything but these questions popped into my head. do you have the correct heat range plugs? Do you need colder perhaps?
Do you have enough spark energy? Is it getting 'blown out' when the boost is peak? Is the gap too wide?
Can your ECU make a longer duration spark?

Cheers
Marc

Good questions and considerations!
All of your suggestions I am trying out or will soon.
Last time I only needed to ground the ecu which solved the misfires then completely. All grounds seem to be solid now though.
Tried lower coil on time, no difference. Just bought colder plugs (8-NGK), but that was never an issue before, but maybe I killed a plug during the mishap, you never know how they are inside hey..
Coils seem fine as well as it runs good on only the top plugs or only the bottom plugs. At least at idle. Its weird and takes a lot of time..

Wally wrote: ↑Sun Jul 31, 2022 11:49 pm Well, I found the weak link in the build
This happened at a local test 'n tune dragrace venue at around 1,5 bar with highly fluctuating boost.. now I know why. 1/4 mi end speed was still 198 km/h with this happening at that run.

Apperently one of the barrels had been clearenced just a tad too much and/or I must have experienced a case of high speed knock...

Wally, I don't remember having seen a cylinder break full length like that before. Also, (in the top pix) the break seems to be somewhat in-line with the stud. What does the engine case look like in the same area?

Lee

Case was totally unhurt in that area, as were ring lands or piston rings..
There was just too much clearence grinded under that stud in the cilinder wall is my explanation. When I did the new one, it could be done with much less clearence, and leave more material there. I hand filed and dremel’d it, which also left the cylinder fins above intact. It all helps strength.
The Deutz Mahle barrel was a b*tch to machine in the lath I understood so this new one is the right material again for which the Deutz cylinders are renoun (sp?)!

Well, long story short: the replacement Deutz cilinder installed with the existing - used, but relatively recent - piston rings bedded in oke I guess as cylinder compression was right back to what it was (a touch better even) after less then 100km's or so
Besides a retune with more convervative timing I proved to be on the edge of knock on the onset of boost, so only corrected that part and it does at least 1.4 bar boost relatively safely. Altough I suspect I might need total seal rings for the second ring pack or so in the future as it does seem to be at the end of the case vent capacity. I also dremelled the intercooler entrance and exit after ten years of use as the edges in there were pretty rough after welding the hose extensions at the current locations.. as said, I run it for, like ever, like this, but sometimes you feel the need for more (air)speed
Next saturday is a dynoday. Hope there is some time left to also dyno mine. The week after I intend to travel to the UK (VW Action), Santa Pod to try and run into the 10 seconds... fingers crossed for both events.

These are some pics taken last week when I went to a test&tune dyno event on tarmac for street cars. Unfortunately no recorded for passes and it was also extremely hot (30-32 degrees C).


Rear wheels are different 8,5J boxer rims with M&H drag radials 245/45/17

Thanks for the update! Glad to hear the new cylinder is behaving admirably! Good luck this weekend! You ready to throw all of the boost at it yet?

Chip Birks wrote: ↑Wed Aug 24, 2022 1:54 pm Thanks for the update! Glad to hear the new cylinder is behaving admirably! Good luck this weekend! You ready to throw all of the boost at it yet?

No, deffo not: I really really want to make Santa Pod this year after 10 years not being able to..
I think 1,6 bar with the current tune should be interesting enough though

Cool walter, good to hear.

Wally wrote: ↑Wed Aug 24, 2022 2:01 pm

Chip Birks wrote: ↑Wed Aug 24, 2022 1:54 pm Thanks for the update! Glad to hear the new cylinder is behaving admirably! Good luck this weekend! You ready to throw all of the boost at it yet?

No, deffo not: I really really want to make Santa Pod this year after 10 years not being able to..
I think 1,6 bar with the current tune should be interesting enough though

I agree. Good goal to take there there in a conservative 500hp tune

Great update! Are you still water injecting while on boost? Bring a couple of 20 litre fuel cans with you and fill them with E85. Mix this with the fuel you have in the tank, crank that boost up and let her rip @ Santa Pod. That should do the trick and make her fly.

Tnx Kalle!
No Ethanol for me as fuel. I really want to do this with pure gasoline. Yes, there still is WI from 42% duty cycle onwards. Not been able to reprogram that 42% (Aquamist) but its fine for now.
I am less worried about detonation as I am about blowby tbh.. we’ll see

Happy to report that all went well and my one run at 1,6 bar boost was about 1,66 bar at its peak and that gave 473hp crank.
At this dyno a 50hp stock 1600 gives 50 crank-converted hp.
Next week Dragtime @ Santa Pod raceway

After that I’am sure I will crank it up some day untill I see 500+ in the screen

And that with alot of tire spin so the torque in real is way further than the graph tells. Good luck and alot of fun in Santa pod. 10sssssss