2,4ltr N/A twin spark exhaust build

[Wally]

One of the very first start ups. It was a little warmed up already, but had to wait (as always) for the lambda sensor to heat up as its still on closed-loop.


After a few runs 'round the block' here's a small clip of a third gear and second gear WOT pull taken from my dash cam. Its my way of bedding in new piston rings
All on closed off private roads of course

[MegaRookie]

Crap, thats a lot of rpm Luckally you found a long private road there

Enjoy!

Mark

[wreck]

sounds sweet .

[Wally]

Luckily there was a spot on the dyno this afternoon



I'am pretty over the moon with the results for such a low CR engine.
It has 8.8-9 or there abouts but considering the cam it should have 11.0 CR.

To say the exhaust worked well, I dunno. I am unpleased with the dip at 7,5K and the resulting power is only at 7000 RPM, I would have expected around 7,5K but then again, maybe some things were at their limit, I dunno.
The 7,5K dip I suspect can still be ignition fall-out and regaining itself. Any ideas?
After all, the ecu has to ignite 4 (!) coils at the time as this is wasted spark in twin execution..

[MegaRookie]

Whoo thats insane! Very nice Walter! Especially due to the low cr you have!

If you want to know if your ignition/ecu is the problem you could try running on 1 edis coil. Or switch to sequential ignition or work with an extra ignition driver, but I dont know how that would work on an edis coil?

Mark

[MegaRookie]

I mean an amplifier, something like this:

https://www.diyautotune.com/product/qua ... on-module/

[Wally]

If you want to know if your ignition/ecu is the problem you could try running on 1 edis coil. Or switch to sequential ignition or work with an extra ignition driver, but I dont know how that would work on an edis coil?

Mark

I don't use Edis coils. They are Zetec Ford style (from Mallory), but the drivers are within the ecu
Thanks for thinking with me on this one. Its a pity I didn't do one more test runs with coil off-set, but its always afterwards you get the good ideas
Not going back to the dyno N/A I think as I used up all my favours by now

[wreck]

a little more compression and you would be up to the 100hp/1000cc NA , impressive !

[Eddie010]

Who nice Walter, 226 with a 2.4 damn, I would settle for that.
You think it is all in the heads?
7500 Rpms with heavy type 4 stuff is not bad at all… hahahha damn..

[Wally]

a little more compression and you would be up to the 100hp/1000cc NA , impressive !

After 3 years I needed to open the engine (see story at the forced induction forum) and besides the beautifull looking biral cylinders (also from Pieper), I took the opportunity to machine the steps away that were in the heads before. I also cc'd the heads and pistons properly and I only had 1;8,2 CR before!
With 1mm less it will now be 1:9,0 CR. I hope to be able to dyno it again without turbo, but time is scarce before the event mid june where the turbo installation must be up and running (and tuned)..

[wreck]

looking forward to the result , It's a shame to have to hide that sculpture under a cooling shroud .
I've a set of Birals ,made by a friend that builds Formula Vee engines , he did them on a manual lathe over 20 years ago (still on the bus and going well)
A John Deere liner was used and an aluminium cast was made of a 105 cylinder ,then bored , heated and fitted to the liner and then the fins machined in with a parting tool . He made them to suit SBC pistons , 4.02" .

935DC37A-EFF3-4057-9679-55853AB43C46_1_105_c.jpeg

[Wally]

I hope after heating and fitting that the liners were honed to spec again..? but since your engine was build and still runs well in a bus, I guess they were
Do think that birals are the way forward if nickies are out of reach $$ wise. lets hope so anyways.

This is the rather unique cross-section of the cylinder:


Wide iron seating in the head and still slim sleeve into the housing.

[wreck]

Yes the cylinder were finished and honed to match the pistons , 0.002" clearance(hyper pistons) , combined with a hydraulic cam its a nice quiet engine . They were made with thin walls ,to keep the head spigot from breaking through the head stud holes and help keep as much strength in the head as possible. I don't think mine would handle boost well !!
I would have thought the Deutz's would have been awesome in a boosted engine .(What I have on my NA 2.6 ) I have wondered if the Nickies would be strong enough for boost . I wish I could afford a set of Thorsten's heads . Australian dollar , import duties etc put them out of reach .

[Wally]

I would have thought the Deutz's would have been awesome in a boosted engine .(What I have on my NA 2.6 ) .

I think they still are. Not sure what I did to mine though or what exactly cause my troubles. Always be carefull to stick a general 'conclusion' on something from just one example where no one (not even me, even though they were on my engine) know everything that happenend. Its easy to draw conclusions, but very tricky as well..
For instance, my Deutz were new items. Maybe they needed to be put through many heat cycles first before they become stable and stay round enough? I dunno. Too many variables...