3900 Forged Turbo build

[Guest]

After being away from the car for about a year, I was amazed at how easily it started. So I guess the half-life for gasoline is pretty long. I was concerned after a large amount of water was blasted out of one exhaust pipe which didn't appear to be easily accessible to rain water but I imagine if it were a blown steel head gasket somehow the rust that would have accumulated in the cylinder over the time it sat would have locked the engine. It idled fine for quite a while and I haven't seen anymore water from the exh pipe so my guess is rain water rolled down the bumper into the pipe.

The crankshaft has been offset ground to 3.430" stroke and the rods should be ready from the narrowing process tomorrow.

The end result should be about an 11.5:1 compression engine after the stroke increase and 9cc dish Forged LS1 pistons provided I don't have to notch them for valve clearance. I've run the engine under some pretty "mean" conditions upto 8psi on midgrade fuel and the most I got out of it was about 1 degree worth of knock retard and I'm sure that's the result of the poor tune in addition to a spark table with a little more advance than the stock Turbo Grand Prix main spark table. With the HD aluminum radiator, post turbo water/meth, oil cooler and possible addition of preturbo water/meth injection, I believe double digit boost will not be a problem at all. The goal is high output, high fuel economy and proof over speculation as to what is practical boosted compression in modern motors.

I'm running the same reground camshaft at this point since I under estimated and had the back-up camshaft reground for specs in between the stock and current cam instead of even more duration since I'm going up in compression. I believe the end result will be just right given how low idle vacuum is with the current grind fully retarded, it's barely enough for power brakes. With it fully advanced it's fine.

The swap thread will be finished with the final engine install: http://60degreev6.com/forum/f109/390...o-fiero-t37902

[Joseph Upson]

Not to provoke debate, but I feel the stock exhaust system the engine came with is perfect for a single turbo in the Fiero. I only wish I had been thinking on a "KISS" level when I first started the project. The ports in the manifolds are very well contoured and directed towards the exit. The crossover is stainless with a bellows joint and is just shy of 2.00" in diameter. I have the heat shields also but I'm going to wrap it anyway to make sure the heat is well contained. I may put the wastegate over the O2 sensor bung, or possibly on the molded area on the rear manifold at the merge point of the front bank. I doubt very seriously that any header outfit I could build, including the one I currently have on the car will out flow the stock system design by enough to warrant going through the trouble of building it. Unfortunately I blew $100 on some mandrel bends and a V-clamp before I remembered that I still had the O.E. exhaust manifolds that came with the engine. If the shipping fee had been in my range it would have been ~$155 as I would have purchased another pair of exh flanges. I'll cut off the flange and weld the T4 flange on to maximize the outlet area going into the turbo flange.

[robertisaar]

11.5:1 with double digit boost... this should be interesting.

and by midgrade, you mean ~89octane? and was that just the stock motor? because 8PSI with ~1*KR at 9.8:1 CR is awesome.

[Joseph Upson]

11.5:1 with double digit boost... this should be interesting.

and by midgrade, you mean ~89octane? and was that just the stock motor? because 8PSI with ~1*KR at 9.8:1 CR is awesome.

That's correct and there were areas under boost with the BLM as high as 165 and a few moments where the Air fuel ratio meter bottomed out for as long as a second and still no detonation. There is a BMW M3 blown outfit that I linked to under the information section I believe, that runs 11.2:1 compression and about 8.5 psi with just an intercooler to pretreat the air. In my case I have an intercooler, piston oil squirters and a heavy duty radiator to keep liquids around 175-180 degrees plus the water/meth and the 93 octane option and I can reduce the boosted part of the spark timing back down to O.E. specs. 10 psi at a minimum should be within easy reach.

Here's the beemer link: http://www.da-motorsport.com/projeler/mz3/mz3_en.htm

[MidnightriderZ24]

wow that exhaust setup is PERFECT! joseph, the story is totally plausible, i had a guest at work 2 weeks ago that her bf owned a 2007 g6 3900, that he went to iraq, came back (the car sat in a garage). and it ran like shit after a year and a half. #4 cylinder was rotted with rust, and when tryin to run it, the rust ruined the wall.. loooks like its going to be a killer setup, happy boosting!

[MidnightriderZ24]

That's correct and there were areas under boost with the BLM as high as 165 and a few moments where the Air fuel ratio meter bottomed out for as long as a second and still no detonation. There is a BMW M3 blown outfit that I linked to under the information section I believe, that runs 11.2:1 compression and about 8.5 psi with just an intercooler to pretreat the air. In my case I have an intercooler, piston oil squirters and a heavy duty radiator to keep liquids around 175-180 degrees plus the water/meth and the 93 octane option and I can reduce the boosted part of the spark timing back down to O.E. specs. 10 psi at a minimum should be within easy reach.

Here's the beemer link: http://www.da-motorsport.com/projeler/mz3/mz3_en.htm

im pretty sure the M engines had piston oil squirters...?

[RedZMonte]

nice, where is the WG? i assume its external.

My car sat for over a year... LOL ran like shyt untill i beat it and boosted for the 1st time.. then she freed up.. dunno if it was a sticky valve or what... from there she has loved every bit of boost i have feed her.

S

[Joseph Upson]

I didn't know about the beemers having oil squirters, but felt mostly that the combustion chamber technology used in the aluminum heads provided a benefit at least equal to what they have in that single long cylinder head. The stock rods are also notched for an additional oil squirter but I didn't think it was necessary or cost effective to duplicate it on the chevy rods.


Usually when you let these engines sit for 6 or so months the injectors tend to stick a little in my experience and the engine starts with a miss for a short while. Maybe the injectors being fairly new with about 7000 miles on them is why that didn't happen along with the later design, Multek 3.5 I believe.

[Joseph Upson]

So far everything fits in place. The piston sits just below the deck or near even with it. I didn't install the rod cap because they have alignment sleeves that aren't very cooperative with cap removal. When it's all completed including the flywheel change the entire rotating assembly will be upwards of 10 lbs lighter. The G-tech analysis will have to wait as the second cheap gear shift cable failed today just after install of the seized selector replacement so I will not get to test drive the car before leaving.

[ForcedFirebird]

I'll be watching this as my car will finally get some attention at the new-found shop. 11.5:1 and turbos.

Simple is good, as I am finding. Wish I would have just shoved a different motor in to begin with. After doing motor swaps on a weekly basis at the shop shows me what a fool I was. Live and learn.

[Joseph Upson]

Headache time

Finally got around to checking valve to piston clearance today only to find at the end it's worthless as the machinist did not do what I explained I wanted done to the crank.

He did an excellent job of radiusing the crank in place of the stock undercut (clue #1), unfortunately that radius creeped into the bearing surface which pinched the wider chevy 2.00" bearing. The 3400 bearing works but is not quite centered. No problem, there maybe chevy race options that are narrower or I can have a custom set made.

Back to the radius. If you explain that you want a 2.25" journal, offset to 2.00" and that you have ~.125" to work with and that you want the metal cut from the bottom of the pin so that the stroke increases outward by .125 minus cleanup, and don't cut the top of the pin except to clean it up, I would hope one would understand that the top of the pin is not to be cut except minutely where necessary. This means that you can't possibly radius the entire diameter of the under cut stress area unless you weld first or cut considerably below the desired stroke.

I explained all the above after saying I wanted it stroked to 3.43 so he would understand I didn't mean .012"/2= .006" above and below to get 3.43, but a full
.125" shift outward. I explained stock rods are 5.827 and showed him the 5.7 rod they were being replaced with so he could make a mental comparison.

Now I have to wait until Monday to contact him to see if we can't work something out. Now I know no matter how competent the machinist is, from now on I'll be providing connect the dot easy drawings and ABC explanations.

As it stands the piston bolted down sits .096 below the deck at TDC plus the head gaskets ~.064 so it's a safe bet he didn't weld anything. I'll find out what went down when I get in touch with him.

Let this be a lesson to those having machine work performed for this engine involving an offset grind. Draw it on paper with big numbers and no room for excuses.

[ForcedFirebird]

Sounds like it was turned straight down.

EDIT: Did you check the oil clearance between the bearing and crank?Tthe pin should be 1.98-1.99".

[Joseph Upson]

Sounds like it was turned straight down.

EDIT: Did you check the oil clearance between the bearing and crank?Tthe pin should be 1.98-1.99".

1.995 by my measurement. After looking back I know I was clear about what I wanted, I physically pointed at the pin and said "don't take anything off the top of the pin, remove the metal from the bottom and cut the top to clean up the circle only if needed. I want the pin to move in this direction (outward) by .125". He gave no inkling that he didn't understand what I wanted and I left feeling he understood fully. I add the .125 to 3.31 to get 3.43, but he must have ignored what should have been a conflict to him based on my request that he not touch the top of the pin and that it needs to move outward by .125. You can't have both with his thinking yet he said nothing to the contrary. I even showed him my rods and told him there is a .127" difference in length, 2nd grade math is simple enough to make the needed correction in the crank obvious.

He's offering a $50 discount to regrind another but I'm going to write him a nice constructive letter reviewing the conversation that he showed he understood. Otherwise I'll deal with someone else. It's partly my fault because had I approached the situation as if he were incompetent he would have had a drawing with measurements and an error based on that is not a mistake, it's defiance. I listen to my customers, and when they make a request that doesn't make sense or there is a conflict, I let them know so that when they put their money down, I know what they want and they know what they're getting.

I'll put the crank up for sale, he did a wonderful job radiusing the pins which is stronger than the stock undercut. The one up side is that I'll have to enter a larger stroke value in Dyno which will estimate higher output.

[3400beretta]

It's not your fault man. I've had to learn the hard way as well. 95% of the people out there in this world just have NO clue. Even when things are spelled out to them, it comes down to them just either not giving a shit, or thinking they know best. I've lost my faith long ago and I no longer regard anyone I deal with as competent, unless they first hand prove otherwise. Hopefully this guy makes it right for you, but sadly I wouldn't count on it.

[Joseph Upson]

It's not your fault man. I've had to learn the hard way as well. 95% of the people out there in this world just have NO clue. Even when things are spelled out to them, it comes down to them just either not giving a shit, or thinking they know best. I've lost my faith long ago and I no longer regard anyone I deal with as competent, unless they first hand prove otherwise. Hopefully this guy makes it right for you, but sadly I wouldn't count on it.

At least the second machine shop got the rods right. I'm gonna contact him and let him know how much I appreciate him calling and telling me after his initial commitment that he would need to direct me to a machinest he knew because he didn't feel his equipment or his experience were enough to do the job right after seeing that the rods were offset and center would need to be located in order to make sure the right amount was removed from each side of the big end. That only cost me $30 more than the initial quote, a small price to pay for having it done right the first time compared to what the crank fiasco is going to cost me to correct.