hitting the back of the valve

[joel.truher]

hi, i'm trying to decide on injector placement for my super-mild NA 1600, and parts to facilitate it. i've read that the best arrangement is to try to minimize the amount of contact between the injector spray and the manifold walls (i.e. "wall wetting"), to reduce the challenge x-tau tries to solve. instead, the idea is to try to get a narrow stream directed exactly at the back of the (hot, closed) valve, to maximize vaporization. is hitting the valve super important, or is hitting the port good enough? i'm particularly concerned about puddling because this will be an e85 car, eventually, and e85 has low vapor pressure components.

i have in mind to use the jenvey dcnf tb's with berg 585a manifolds and pico injectors. i like this setup because it's small and "old school." can anyone provide any guidance about the geometry of this setup? i also considered the vw speed shop throttle/manifold, which i like for its simplicity and its low injector position, but it seems more important to keep the two ports separate. i also considered the mexican setup, but i'd rather have itb's. if anyone has any advice about any of these options, i'd appreciate it.

what about injectors? does anyone have recommendations for specific ones? are there wider and narrower spray patterns?

thanks in advance.

[MarioVelotta]

It's always a good idea to inject at the closed valve like you are talking about. But it's hard to achieve in our cars unless you have bigger ports and make custom rails for manifolds that you weld bungs into.

The next thing is the un-timed injections of batch or alternating fired injectors. You would have to go right to sequential ignition knowing your cam specs to be able to make an educated guess at the crank angle at to which time to fire the injectors. There are a few spreadsheets floating around to help fill in the injection timing tables, I have tried my hand at it as well. It makes a big difference when you start getting close to the correct injection time. Most keep the table stock at a 360° injection angle and are not taking advantage of the benefits of getting it right. All this doesn't matter much when you get higher in the rpm as there is enough fuel in the manifold that it becomes a non issue. Usually much over 3-4000 rpms.

I just took the Mexican setup off my stock 1600, made 60hp with it and then 90 with a turbo at 9psi. I am not in the middle of putting some 38mm dual throttle bodied on, putting my MS3-PRO or MS3x back in and doing all these neat little tricks to see how much more I can make over that 60hp.

[joel.truher]

ok, cool, thanks mario!

[Steve Arndt]

For your "super mild 1600" I would go with the standard Mexican intake setup ported out to match your heads. It has near perfect injector location given all the constraints of actually fitting the engine. If you want to keep it mild then I feel individual throttles are not the right choice.

[Paul H]

hi, i'm trying to decide on injector placement for my super-mild NA 1600, and parts to facilitate it. i've read that the best arrangement is to try to minimize the amount of contact between the injector spray and the manifold walls (i.e. "wall wetting"), to reduce the challenge x-tau tries to solve. instead, the idea is to try to get a narrow stream directed exactly at the back of the (hot, closed) valve, to maximize vaporization. is hitting the valve super important, or is hitting the port good enough? i'm particularly concerned about puddling because this will be an e85 car, eventually, and e85 has low vapor pressure components.

i have in mind to use the jenvey dcnf tb's with berg 585a manifolds and pico injectors. i like this setup because it's small and "old school." can anyone provide any guidance about the geometry of this setup? i also considered the vw speed shop throttle/manifold, which i like for its simplicity and its low injector position, but it seems more important to keep the two ports separate. i also considered the mexican setup, but i'd rather have itb's. if anyone has any advice about any of these options, i'd appreciate it.

what about injectors? does anyone have recommendations for specific ones? are there wider and narrower spray patterns?

thanks in advance.

Those 42mm throttle manifolds work well on 1600's We made 47rwhp with those on a bone stock motor with standard pea shooter exhaust and 52rwhp with s 1.5 inch merged header with the fan belt on and my dyno is not generous.
Next motor on the dyno for playing with is an original Mexican 1600 with efi, I made a converter kit so I can use regular 19lb injectors in the OEM end castings and fuel rail (don't trust those old things) Might even try my new 36mm Solex replacement TB on the mexican manifold if it will fit-then on with the twin 42's for comparison and then maybe some 38IDF's
I mainly need to find out if the actual motor is any good

[MarioVelotta]

hi, i'm trying to decide on injector placement for my super-mild NA 1600, and parts to facilitate it. i've read that the best arrangement is to try to minimize the amount of contact between the injector spray and the manifold walls (i.e. "wall wetting"), to reduce the challenge x-tau tries to solve. instead, the idea is to try to get a narrow stream directed exactly at the back of the (hot, closed) valve, to maximize vaporization. is hitting the valve super important, or is hitting the port good enough? i'm particularly concerned about puddling because this will be an e85 car, eventually, and e85 has low vapor pressure components.

i have in mind to use the jenvey dcnf tb's with berg 585a manifolds and pico injectors. i like this setup because it's small and "old school." can anyone provide any guidance about the geometry of this setup? i also considered the vw speed shop throttle/manifold, which i like for its simplicity and its low injector position, but it seems more important to keep the two ports separate. i also considered the mexican setup, but i'd rather have itb's. if anyone has any advice about any of these options, i'd appreciate it.

what about injectors? does anyone have recommendations for specific ones? are there wider and narrower spray patterns?

thanks in advance.

Those 42mm throttle manifolds work well on 1600's We made 47rwhp with those on a bone stock motor with standard pea shooter exhaust and 52rwhp with s 1.5 inch merged header with the fan belt on and my dyno is not generous.
Next motor on the dyno for playing with is an original Mexican 1600 with efi, I made a converter kit so I can use regular 19lb injectors in the OEM end castings and fuel rail (don't trust those old things) Might even try my new 36mm Solex replacement TB on the mexican manifold if it will fit-then on with the twin 42's for comparison and then maybe some 38IDF's
I mainly need to find out if the actual motor is any good

I'm in the process of putting the 38's on mine right now Paul, we can compare numbers. I will have a 1.5" exhaust as well.

My numbers from the Mex EFI where through an 1 3/8" cheap merged header.

[Paul H]

I've been meaning to pull this engine out for about 3 years, just got around to fitting the new injectors.

What's the factory claimed HP numbers for the mexican 1600i ?

[MarioVelotta]

Engine Specifications
Power rating 34 KW (44 hp) at 4000 rpm
Max torque 98.1 Nm (132 ft-lb) at 2200 rpm
Displacement: 1584 cc
Bore 85.5 mm
Stroke 69 mm
Compression 7.75:1
Fuel Required: 87 AKI (regular unleaded)

Rated fuel mileage 13.9 km/l (32.5 US mpg)
Max cruising speed: 127 kph (78 mph)

Spark Plugs NGK BP5ES-A (3/4” thread length); Champion N12Y
(VW part # 101 000 047 AA – set of 4)
Plug electrode gap 0.7 mm (0.028”)

[Paul H]

Thanks for the info
I'll see what it makes at 4000rpm the exhaust isn't standard as it came out of a trike and I don't know whether they quote power figures with or without the fan belt which is 5 to 8 hp at 4k

[MarioVelotta]

I want to know how they made twice the torque at 2200

[Paul H]

Yeah just noticed that. 132ft/lb is more than a 2litre T4
I'll test it and put a graph up

[Steve Arndt]

Atomization discussion.
FYI, poster "Yawpower" is the person behind Injector Dynamics.

http://www.gtrlife.com/forums/topic/827 ... injectors/

[MarioVelotta]

41 pages! Are you kidding me.

[Steve Arndt]

I only made it through the first two, but there are some power players posting.
Just weed out the fluff as always

[Paul H]

I couldn't wade through that lot
anyway
Steve
I saw you post this on another forum

A test:

Lock your timing then rev the motor at ~ 2500 RPMs/second acceleration rate with a timing light on the pulley. Watch the timing LEAD while accelerating (NOT GOOD for a raged edge tune) and lag while decelerating. This is where a fast degree based ECU and resolution trigger come into play. With a locked dizzy or crude event based ECU will have major lead/lag. Like six degrees more timing than you actually commanded.

Who fed you that BS ?