2,4 type4 turbo 500hp -on gasoline- goal

[Wally]

Think this is the last (and best) run I did complete with a small flame and small wheelie :

[brewsy]

Awesome Wally!
Sequential box or maybe PDK next?? Surely there isn't much more you can do engine wise (is there?).....

Cheers

[Wally]

Engine wise from the concept there is indeed little to be done I think, but I still did see some hints of what could be improved: ring seal is definately not optimal al as the case ventilation (breather box) did spit out a bit too much oil fumes. Think I need to see the cylinders and rings and maybe upgrade to Total Seal rings, but lets see first if there is visual evidence for something going on or not.
Also I did notice from the logs that the two into one wastegate set-up is not keeping up with demand. There's a short boost spike in each gear, so going (back) to twin gates seems the ticket here. I would have done so from the start if I wasn't in a hurry and/or had ample room. Refitting the wastegates plumbing back to the muffled downpipe might be best too (its screamer pipe now) since I intend to do more circuit driving after the 10-second goal now has been met

In theory, with a better seal and better boost control and since the engine has been made for a little more boost, the 500 goal should be very doable, maybe even at the same boost? In fact I think it would be possible now already as well without slippage on the dyno and/or a little more psi maybe, but that would hurt my mechanical inclined heart too much I think

An automatic or something else gearbox wise does not seem to be needed with the tires and spring rates I used at Santa Pod, so I'll just keep that not to overcomplicate things

[brewsy]

Cheers for the swift and technical reply.
I have no clue who might be doing this in Europe but Stef at Ace Racing in the States seems to be doing a roaring trade with his new(?) cylinder honing. (Not sure if its the honing or the shiny new measuring tool that he has) Seems that his results with the new 'ported' total seal rings are giving amazing leak down numbers.
Is now the time to go dry or 'moist' sump and start extracting from the crankcase??

Cheers

[Eddie010]

Wally on the case ventilation, do you have an extra breather hole in the case at the #1 en #3 cilinder.
I see that done on bigger engines like yours.

Regards Eddie

[Wally]

Wally on the case ventilation, do you have an extra breather hole in the case at the #1 en #3 cilinder.
I see that done on bigger engines like yours.

Regards Eddie

I run dry-sump. The lay-out is not the issue here imo.

[Eddie010]

Wally on the case ventilation, do you have an extra breather hole in the case at the #1 en #3 cilinder.
I see that done on bigger engines like yours.

Regards Eddie

I run dry-sump. The lay-out is not the issue here imo.

Ooooh that is true, I always forget that.

[Wally]

In the meantime I have the motor out and took the heads off to look for signs that could explain the excessive case presussure I experienced.
I had expected to find maybe a broken piston ring, some ringland damage or something like that. Nope.

As I had not expected this, I thought this might be something what could happen to most of us with bigger bores and decided to video it (seeing is believing?):

[Chip Birks]

Thanks for the video! What do you think the solution is? I had always thought that those cylinders were pretty much bullet proof. Back to aluminum?

[Wally]

Thanks for the video! What do you think the solution is? I had always thought that those cylinders were pretty much bullet proof. Back to aluminum?

,
Yeah, what to do now is the million dollar question..
I think establashing the root cause first is key. From what I have seen, they were fine new, so using them made them unround. Its an open door, but that leaves two possible causes and probably the participated both here: heat and pressure.

Allthough I did see signs that the cilinder pressure did do something as the cylinders were a bit wider in the middle in general then all the way top or bottom.
The ovality at all heights was worse though. The only conclusion then is that heat made them unround. Likely the resulting temperature gradient was too high, meaning some parts in the radius got (way) hotter then other parts of the cylinder, despite the nice and trick cooling system I run.

Unfortunately - and as much I hate to admit this - most alu cylinders I have run could not with stand the cylinder pressures unless you would sleeve them with the cylinder head opening (thats a sort of joke, but not entirely..) or so.
The very best alu cylinder sleeving is however a biral cylinder. When done properly, they are awesome for boost and cooling well imo.
My 98mm AA birals were still within 2/100 ovality after the 1 bar and 400hp turbo abuse, even though they just have a 3,5mm wall thickness. Thats half of the Deutz cylinder! Strangely the AA's had much more taper then the Deutz cylinders, but I guess that was probably build in the AA's (top being about 5/100 smaller then the bottom..)

Still not entirely sure what I'd do, but I speak to a few high end tuners in germany in 3 weeks (X-mas-winter indoor show in Herford), so lets see what they come up with. Thorsten hinted he could make me a 102 biral... that would be interesting..

to be continued.

[CobraJet]

Thank you for your report Wally! Darn it anyway, I was thinking on running a set of the Duetz at 101.6 in the engine that I'll be building. Makes me rethink things for sure!

[Bruce.m]

I vaguely recall that a nice used item with lots of heat cycles was the preferred starting point for these cylinders but I might be inventing that memory.

Perhaps take the new one and stick it in a gas BBQ for a hot “bath” then re measure it to see if it has relaxed, before it gets bored to size.

[Bruce.m]

Could you fit a modern steel liner? Is there lenough spare thickness in the cylinder for that?

[Wally]

I vaguely recall that a nice used item with lots of heat cycles was the preferred starting point for these cylinders but I might be inventing that memory.

That story has been told to me several times as well, directly from the source, being old rallycross ('buggy's) racers that seriously competed 40 years ago with type 4 engines in these. I can see now what they may be getting at back in the days.
OTOH, Jake has warned several times for warping of the cast iron 103 cylinders getting unround, so nothing shocking actually. The thickness of these Deutz cylinders is maybe both a strong point (strength) and a weakness (shedding heat more difficultly) at the same time.

[Wally]

Thank you for your report Wally! Darn it anyway, I was thinking on running a set of the Duetz at 101.6 in the engine that I'll be building. Makes me rethink things for sure!

Just be carefull reading anything conclusive for other builds from my very specific application! It could probably work for you very well (boring out 100mm jugs I presume), where I did new 102's as is in a very high hp application. Don't discard them just because I made them unround is what I'am saying