bad cylinder distribution?

[slostar]

interesting idea, will look into it.
setting it up on the floor with the first part of the intercooler pipe attached, including the water injection jet. then adding an air supply to the intercooler pipe. and doing a few tests, may be good enough to show the floors in the wi. wonder if a leaf blower would push enough air ?

simple: i seen that pic in your other post. does look pretty bad desnt it.. looking at it from the outside anyway

[simple]

Slostar : I have spent some time looking in possible solution to bad water distribution (for my case) the only reasonable and cheap is to fit one nozzle per intake. All other solutions simply introduce more variables which are difficult to account and controll

[hotrod]

I suspect you have a "wet flow" problem. Log style manfolds like that might move air quite well but when you put a liquid mist in the air flow things change rapidly.
It is very likely that you have one or more cylinders that are not getting their fair share of water.

You could play around with a flow bench and do some wet flow testing but it is a pain to set up as you have a lot of liquid in the air flow and most flow benches are set up as suction devices that pull the air through the motors.

You could try to find an UV dye that will mix with the water and run it for a bit then pull off the manifold and see if the dye points out the problem.

The more certain solution would be to configure that as a direct port injection after the runners break off of the plenum.

I suspect your getting the liquid mist centrifuged out of the air flow as it tries to make the turns into the runners and one or more runners is getting short changed on the water mist. That style of log manifold is notorious for having unequal fuel flow problems in carburated systems due to this sort of wet flow problem.

You might try reading your plugs for signs of detonation, that would clearly show if your only detonating on a single cylinder, and which one is having the problem.
Put new plugs in the engine, take it out and run it up until you detect that light detonation, then pull the plugs and carefully examine them. The cylinder that is detonating should show signs on the plug electrodes and center insulator of very small specs.

Larry

[JohnA]

Can I also add that air/mist distribution under boost is not necessarily as uniform as under vacuum.
You really need to test for both.

[simple]

Originally Posted by JohnA

Can I also add that air/mist distribution under boost is not necessarily as uniform as under vacuum.
You really need to test for both.

Will i be asking too much if I ask to explain why?

[slostar]

only just realized this forum was working again.. thanks for your comments

i ended up doing a quick test with a garden leaf blower. first connected to the section of the intercooler pipe with the jet. with no manifold connected. it had a nice mist coming out the end of the intercooler pipe. now with the manifold connected, there was very little mist. be it with all the runners open, or 3 blocked etc. from memory some were slightly better than others, but not alot. so the mist was basically puddling in the plenum, then dribbling out the runners. sure its alot different to being on the car, but was enough for me to bin the single jet setup and try something else.

so its now running port injection. unfortunately i haven't had time to test it, against the original setup.
had a drag meet coming up, and managed to get a hold of some better fuel. witch made it easy to tune quite a bit more power out of it. but soon as ive ran out of the good fuel, will do some more testing.

[JohnA]

Originally Posted by simple

Will i be asking too much if I ask to explain why?

It's a matter of scale.
Vacuum is milder, usually it creates air movement due to pressure differences of a few psi, doesn't it?
...while boost can lead to pressure differences of dozens of psi, so airflow will tend to be far more turbulent. Minor eddies (appearing under vacuum tests) could turn into serious airflow obstacles under boost.

[keithmac]

slostar, I`m in the same boat as you with the log style manifold, going to try port water injection myself as well, hopefully have some good results..