new turbo engine start up tuning procedure

[kirkallen143]

Howdy All,

Once I start the engine, is there any certain technique? Is it best to tune first with bonnet off to get it running at idle and then attatch bonnet and tune from there? That way I can set my base/initial timing and ilde mixture or leave it all together and go for it, tuning that is. Let it warm up, plug timing adv hose, adjust as necessary. Adjust idle mixture screws and then set idle once adv hose is hooked back up. I'll start at 10*, never knew how many total degrees the vacuum adv has, which is hooked to the manifold side of the carb, but I have the centrifical limited to 20*. I also have the retard mechanism hooked to port side of carb, and do not know how many degrees it retards timing, either. I'll have to play with it... maybe not even use the vacuum adv, only the retard, so can use more adv timing from base/initial setting. Let the fun begin, and thanks goodness I have finally gotten to this point. Appreciate any responses.

Kirk
ps. engine goes back in tonight! YEEHAW!!!!!!!!!!!!!!!!

 

[Does10s]

What we did on Kelly's car was to not have the carb hat hooked to the the turbo. We just let the turbo blow into the atmosphere.
We did the normal run up, break-in procedure, checked the timing, then took it for a drive. Turbo still unhooked.
Then retarded the timing to around 8*, hooked up the turbo piping to the hat, set the wastegate VERY LOW (I think it made only 4-5psi).
Then started the tuning process from there.
Don't forget to run it fat and retarded for awhile.
Good luck!
Keep us posted!
Will

 

[hasa68mustang]

this may come inhandy for me aswell tonight! Thanks.

 

[XFlow_Fairlane]

I wouldn't drive it with athe bonnet off....with an internal wastegate you can over rev the turbo pretty easily (there is no load on it)

I just turned my carb to it idled and reved fine withthe bonnet off it and parked...then onceI got my cable setup finished up I took it for a spin with the bonnet on it. I have driven SHORT distances with it off (like down the block always under 1/2 throttle)

one thing about it being rich is that simply dropping a jet size will make it spool WAY faster since there will be more heat/energy in the exhaust from going leaner. I was amazed how big a difference a single jet size made on my motor. I hav ejust slightly retarded tiing right now.....mostly since it is giving me better milage (25mpg) I am putting off with the weaker top end for the milage right now (been highway driving it ALOT....200+ mile one way trips)

 

[Does10s]

Turbo_Fairlane is correct. Thanks!

I made the assumtion that he wouldn't try to floor it during the first drive. So just driving it around "in vacuum" wouldn't hurt a thing.
Later,
Will

 

[kirkallen143]

Shall do, I appreciate the responses. Had the motor on lift ready to install and while attatching the flywheel, clutch and bellhousing the dang wire spring clip that holds the fork inplace decides to break on me,!@#$%^&*!!!!!!!!!!!!! It is always something, ain't it, and just try and find one in Houston, hell even Ford parts dealer did not know what it was,!@#$%^&*!!!!!!!!!!!!!!............................................................OK, I'm better, thanks for the vent.
I guess I'll just stick the bellhousing on later, sure is easier to get to now, though. Hey what about using bailing wire?

Kirk

 

[kirkallen143]

Found a clip retainer, manual trans shop @ $5.00 plus tax. ALLRIGHT!!!!!!!!!!!!!!

Kirk
ps. now if I can just get out of here early.

 

[Anonymous]

1) I'll start at 10*, never knew how many total degrees the vacuum adv has, which is hooked to the manifold side of the carb, but I have the centrifical limited to 20*.

2) I also have the retard mechanism hooked to port side of carb, and do not know how many degrees it retards timing, either.

1) 20* centrifugal seems like a lot. You may have to take some out later. Start by timing with as much initial as you can to make low-end torque, then take centrifugal timing out (by modifying the mechanism) to keep total limited to a safe number.

2) What is that device?

Found a clip retainer, manual trans shop @ $5.00 plus tax.

That ROX!

What jets and power valve do you have in the carb now? If it isn't written in a "log book" somewhere, it should be.

Did you drill the power valve restrictions? What size?

Leave the vacuum advance completely disconnected for now, just get it to run halfways descent with just the carb and the timing locked in one place. You can hook up the vacuum advance later when you get a feel for how to tune the engine. Taking timing out of my engine didn't seem to make a lot of difference in either power or detonation, but sure hurt low end torque a LOT with too little timing advance (trying to launch an automatic off the line)

Timing doesn't seem to affect the peak power of a turbo engine as much as I thought it would. Just run as much as you can while not detonating. Start with higher octane gas and work your way down when tuning. The higher octane will help prevent burned parts from happening with a tune with too little fuel or too much timing (only to a certain degree, though.)

yeah, don't put a load on the engine with the turbo disconnected. I would do all the driving tests with the turbo hooked up, just watch your boost gauge like a hawk so you can let off the gas if it gets too high.

 

[drag-200stang]

Hi Kirk,

Your set up looks nice. You may have this covered and I know you're not building a drag car, but a hung up throttle or a broken drive train at full throttle could lead to a clutch pressure plate explosion. Your hydralic cam may keep the revs down below 6500 but a rev limiter would be a good bet if you don't already have one. I had one OEM style cast iron pressure plate explode so, thinking it was a fluke, I bought a new one. The results were no pieces found of the pressure plate or bell housing larger than 1", blew one ear off the transmission, 2 ears off the back of the block, sheared off the starter nose, 1 header tube, cuts in the floor, but no pieces made it through Ford's thick carpeting.

I found my low compression engine started best with 20 deg initial. I had no vacuum advance, just mechanical on a Mallory dual point.

Good luck,

Jim