Piston Weights?

[alpa]

You're right. Is positioning of this injector special in any way because of the spray-pattern? (When converting Alfa 24V from EV1 to EV6 it is...)

It's a C 80deg spray type. Please check Bosch specs for more information.

 

[A.S. Motorsport]

Well this is what i want to investigate prior to offering this as a package.
On the last fueling injector project (or part of a project) we made 3D printed cutaways to confirm spray angles.

What i want to confirm or module is getting the best AFR on a bi-turbo at low duty-cycle and air speed, this where in the below example we managed to design a ITB inlet that run's like stock on a NSX.

 

[alpa]

Oh this is another level of re-designing !
It's certainly possibly to design a perfect intake plenum and runners for the 24v because intake ports are just perfect. But at what price ? Today NSX is an expensive monument, biturbo are still just a curious scaring exception in the history.
Have a look at VW GTI 16v engines (that I mentioned in my first posts), they had the same Coscast heads (4cyl vs 3cyl). Here is a post with VW heads cutaway:

https://clubgti.com/forums/index.php?threads/the-2-litre-16v-head-cutaway-and-maximum-porting-dimensions-thread.193826/

Believe me the 24v heads work well on low loads/rpm with the original engine, I fully remapped a Primatist few years ago (DTA ECU). The setup was with EV14 dual spray injectors but to me it's a detail, will work as good with one conical spray.

 

[A.S. Motorsport]

Well that's what we intend the make a a upgrade package to our new ecu packages, improved sensors and fueling as a stage 1 upgrade.
I normally use EV14, and i need to see if dual spray pattern's would give sufficient coverage to the intake valve stems. (i have a few concerns and a few placement idea's to improve)

 

[alpa]

I'm afraid it's overkill. We are talking about 300/6 = 50hp per cylinder. It's nothing. The biggest problem with biturbo is their stock approximate calibration.

The EV6 injector I mentioned has a one cone spray. It works perfectly on both 3 and 4v engines. Idle is good. Not perfect, but how could you have a perfect idle with such a low CR and a low CO level ?
All 18, 24 and 32v heads have very well designed intake ports, the 24v is the best for power (two straight totally separated ports), 18v for torque (one bent port for good tumble).
The 24v heads have long straight ports so if you wanted to spray on the valve tulips you'd need to integrate injectors to the head to place them closer.
I believe even with huge 550cc/min injectors (not choosen by me) I had on Primatist the idle needed 1ms pulses (I had to lower fuel pressure), so it's enough for a good idle control (not too short pulses). With 300-350cc it'll be even better.
In high loads the mixture goes all over up and down and even in other cylinders so the spray pattern does not matter. On some high power engines the second stage injectors spray against the air direction, on F1 engines the injectors were at the entry of the intake runners.

I'd be more worried about global imperfections I described in the beginning.
All that makes me think that may be 18v heads need to spray only in the straight port for a better idle control.

 

[alpa]

There is a good dual spray EV6 injector for 4v heads: 280 158 123. Rated 304cc but actually a bit too large as a P&P replacement, I tried on QP4 v8. Still available but rare and expensive because used on Ford XR6 Falcon turbo. You can find them in Australia where the car was popular. Beware of chinese copies.

 

[fphil]

I have mounted the Bosch EV14EL ref 0280158174 dual cone which I found to be the Motorcraft Part CM5144 quite popular. One needs to make some simple adaptations. (I don't know about the piston weights )

 

[alpa]

I have mounted the Bosch EV14EL ref 0280158174 dual cone which I found to be the Motorcraft Part CM5144 quite popular. One needs to make some simple adaptations. (I don't know about the piston weights )

It's a 330cc long injector. What car exactly and what did you do to the injection ?

 

[A.S. Motorsport]

I'm afraid it's overkill. We are talking about 300/6 = 50hp per cylinder. It's nothing. The biggest problem with biturbo is their stock approximate calibration.

The EV6 injector I mentioned has a one cone spray. It works perfectly on both 3 and 4v engines. Idle is good. Not perfect, but how could you have a perfect idle with such a low CR and a low CO level ?
All 18, 24 and 32v heads have very well designed intake ports, the 24v is the best for power (two straight totally separated ports), 18v for torque (one bent port for good tumble).
The 24v heads have long straight ports so if you wanted to spray on the valve tulips you'd need to integrate injectors to the head to place them closer.
I believe even with huge 550cc/min injectors (not choosen by me) I had on Primatist the idle needed 1ms pulses (I had to lower fuel pressure), so it's enough for a good idle control (not too short pulses). With 300-350cc it'll be even better.
In high loads the mixture goes all over up and down and even in other cylinders so the spray pattern does not matter. On some high power engines the second stage injectors spray against the air direction, on F1 engines the injectors were at the entry of the intake runners.

I'd be more worried about global imperfections I described in the beginning.
All that makes me think that may be 18v heads need to spray only in the straight port for a better idle control.

the type of EV has no relation to the displacement/flow, you can get small 14's too,
Further more quicker responding wide spraying injectors will help improve idle and low speed mixture.
As for the placement I need to have a look at a 24V head and Injector setup, i've got a idea how we perhaps can improve position in a bolt on fashion perhaps with cnc'd adapters.

I'll really dig into this deeper after we finish testing the plug ecu kit and can go to the second stage. (improved fueling, and timing sensors)
This isn't only a power gaining exercise, I'd want to improve the reliability and serviceability of the Bi-Turbo so they survive into the future.

 

[alpa]

the type of EV has no relation to the displacement/flow, you can get small 14's too,

I don't see why you are saying that.

 

[Enz0]

24v heads are from Cosworth: one of the best head foundry and design company.
These heads are very good:

• They had a novel (probably inspired by F1) cooling flow: on the exit side (in the V) there is a collecting gallery with two exits to the pump, so that the flow inside the head can be balanced with external restrictors on the exit path.
• The intake seats are round-shaped like in F1 engines (not a 3-5 cut shape)
• Intake ports are straight, almost vertical, with a long separation wall between two ports

The same Cosworth heads (except for the number of cylinders) were used on VW ABF/ABY/ABZ and few other VW/Audi engines, the most known is the 2L 16v on Golf GTI. VW heads had the same valve positioning and the same camshaft chain without chain tender (however the chain costs 20e and not 200e).
Here is a detailed description of the GTI head cutaway:

https://clubgti.com/forums/index.php?threads/the-2-litre-16v-head-cutaway-and-maximum-porting-dimensions-thread.193826/

These heads have something special: exhaust valves are parallel to the piston top, like in diesel engines. I don’t know why, probably a packaging problem to make heads narrower.

Your story that Cosworth designed heads of both VAG ABF and Biturbo 24v is very interesting. In fact, they seem similar.

Do you have any evidence that Cosworth actually designed them?

 

[alpa]

Your story that Cosworth designed heads of both VAG ABF and Biturbo 24v is very interesting. In fact, they seem similar.

Do you have any evidence that Cosworth actually designed them?

Well it's stamped "Coscast" on them. And VW people do say their heads are from Cosworth. And heads look almost identical. Little chance VW and Maserati would design heads together. There are no other 4v heads with such a valve architecture with exhaust valves parallel to the piston top (I'd say nobody else made the same stupid architecture if you think about the fundamental reasons of hemispheric chambers).

 

[Enz0]

Well it's stamped "Coscast" on them. And VW people do say their heads are from Cosworth. And heads look almost identical. Little chance VW and Maserati would design heads together. There are no other 4v heads with such a valve architecture with exhaust valves parallel to the piston top (I'd say nobody else made the same stupid architecture if you think about the fundamental reasons of hemispheric chambers).

Thank you. That's credible enough.

I have been wondering for a long time why the head design of Biturbo 24v and 32v are so different. I have an answer now.

 

[alpa]

I don't know if QP4 heads are by Cos because I've never seen them dismounted. I'm not sure they are the same as 3200gt ones. But like 3200gt heads (which aren't stamped Coscast) I don't think these heads were from Cos because of their overkill design: DOHC but with cam boxes. It's complicated, tall and heavy. 3200gt have very well designed ports, cooling (same as in 18 and 24 heads) and compact combustion chambers.

 

[Zep]

The upright exhaust valve design was often used because it allowed a narrower head design, useful for lower bonnet lines when putting a new head on an old block.

I do know that the “Coscast” lettering was applied to products that were cast at Cosworth Castings in Worcester using a proprietary casting method to ensure material flowed well, reducing the likelihood of porosity. They were then machined and finished just up the road from me in Wellingborough.

There is no mention of a cylinder head project for Maserati in the list of Cosworth projects (Or VW for that matter), but they do list project YB (Ford 16v head design) and KB (Vauxhall / Opel 16v head). So I am not sure they designed it, even if they did make it.

 

[alpa]

Interesting if Cosworth did not design it. I can't believe VW and Maserati could have worked together on a project . They must have bought this design from the same company.
The fact that there is no room for a chain tender between the camshafts also confirms that this upright exhaust was to save space.
I've never seen any other 4v head with such a mixed right and angled valve placement.

Do you know any other engine that would have same kind of intake valve seats ? They don't have 3/5 cuts, they have a continuous round profile with just one cut for the valve. Not sure I'm clear. I've seen that on pictures of F1 heads (Renault I think).

 

[Enz0]

Maserati released three 4-valve engines in a very short period of time, from 1988 to 1990.

Two of them are made by Cosworth (COSCAST).

• 2.0 L DOHC 24-valve V6 turbo for 2.24v in 1988
• 2.2 L DOHC 16-valve Inline-4 turbo for Chrysler TC by Maserati in 1989

One of them is made by Maserati.
- 3.2 L DOHC 32-valve V8 turbo for Shamal in 1990

We don't know if the former two were designed by Cosworth or not. However, it is reasonable to do so because they know better the limitation of the production method (COSCAST). Also, I don't think Maserati had enough people to design many engines in parallel. It is possible that Maserati used all the manpower to design the all-new V8.

Of course, even if Cosworth designed them, Maserati gave some requirements for them. We don't know how specific the requirements were.

 

[A.S. Motorsport]

Well the Maserati 4V design isn't that odd if you compare valve angles/ports to for example 4V Ferrari or 4V Lamborghini heads in the same period (mid eighties)
Maserati also prototyped and well documented the 6V engines which ran timing belts on all four cams.

It to me always seemed like a rationalized method of for them to run the 4V engine off the exhaust pulley, the chain setup is very similar to VAG but those are different in layout if you see the heads next to each other (I've had them next to each other accidentally at my engine builder)
For Maserati it would allow recycling of a lot of standard items and just adding longer belts and one tensioner, water pump castings, etc.

Also the 4v head doesn't look anything like Cosworth heads in it's segmented design (more reminiscent of a GM OHC) or how the seals and bearings are.
I've seen plenty of YB, DFV, FBA engines apart.

The 2.2 TC engine does look A LOT more cosworth than anything Maserati did just look at the timing gears, single piece head with only loose upper cam bearings etc.

 

[alpa]

Also the 4v head doesn't look anything like Cosworth heads in it's segmented design (more reminiscent of a GM OHC) or how the seals and bearings are.

What do you mean by "segmented design" ? Are you talking about the v6 24v heads ?
32v and 24v heads are radically different.

 

[A.S. Motorsport]

What do you mean by "segmented design" ? Are you talking about the v6 24v heads ?
32v and 24v heads are radically different.

I'm referring the 32V which has the loose cambox.