V6 Strong modification

[FMG_V6_btb]

I think this thread is not interesting for anybody, because anybody makes comments or help with some data, maybe is too much technical for the average level of people in this forum.

Only one thing I can't understand: in many other threads people waste a lot of time trying to know which rod is better... maximum allowable liner diameters... compression ratios for turbo applications... etc. etc. I have tried to put some science here (I'm Automotive engineer and have been involved in some very very interesting engine developments), but if this serves to nothing... bye bye.

[Fedezyl]

Mate, it is very interesting, certainly your knowledge and resources available (not only economical) are above the average person over here, definetely over mine for sure.
But I do find your thread very interesting, and there's a lot of technical data that is very good, keep them coming!

[giuliettaevo]

Most people here are not able to do the work you describe or to pay for it, but please let that not be a reason to quit posting here! i for sure am very interested in your roject and i would love to be able to help you with any question but i'm afraid you're a lot smarter then me...

Greetings Remco.

[Grant]

Don't forget to post on alfagtv6.com/bb, it's a bit more technical over there.

But post here too, so we can all see what you're doing!!!

[chelo]

It's interesting that for 450hp that you would make that many modifications. I have always used H beam rods when I want to make reliable power. The I beam rod seem to always bend. Specially when detonation on turbo engine happens. 8.5 to 9.1 is a great compression ratio for a turbo motor. Although lately many turbo engine builders are bumping up the compression ratio.
A forged crank would be nice but for that price. There are other things that I would be interested in before actually going with a forged crank. In the U.S we tend to cryo and it works great. I have actually been thinking of a girdle to tie in the aluminum block.
I love the alfa engine but they should step it up and start making some nice 6bolt bottom ends. Even Gm is making them with their LS series engines. Look at the picture. Less of a chance of the bearing from what we call "walking". Basicly(sp) moving and caused crank failure.
Making a 450 hp 24v engine can be done with a 3.0. Going big bore and other stuff is more exotic and more $$. I would like to see what the main oiling issues are. I think I had an engine that it happened to. I've been out of the alfa scene for too long.
Es muy interesante lo que estas planeando.

Marcelo

[gattia86]

Barryh,

Any more details on your BMW transmission swap? Which model?
Custom bellhousing, I assume? Any tricks with the input shaft length, pilot bearing or flywheel issues? BMW clutch? Alfa flywheel? What starter?

Also, have you considered the Porsche 928 transaxle as an option? Plenty strong and tall-geared for a turbo engine. Plus, it locates the clutch up front at the flywheel and the gearset in front of the diff, unlike the 944 'box, allowing use of the Alfa deDion rear end. The Porsche "torque tube" design also make a lot of sense for a rear transaxle car, unlike Alfa relying on the unibody to resist torque reaction in the driveline. Just an idea I've been kicking around...

George

[slyalfa]

Quote:

Originally Posted by FMG_V6_btb To avoid misunderstandings about the bent axis etc. here you have a picture from a bent rod around the x axis (that’s the typical bending of the engine rods), so as I explained in my last post, “I” beam rods are conceptually stronger than the rest. Paco.

[giuliettaevo]

Look closely at the drawing.. the arrow indicates the way it bends. if you put one flat on the table and you would pull the two outer ends together while keeping it flat you would get the rod pictured above. the x axis is from the table upwards so you're bending around it.

if you put another conrod on the table and bend the two ends towards eachother by picking up one side and folding it over to the other side while you keep that other side on the tabel you're bending it around the y-axis, which would be parallel to the table.

Hope i explained it clearly so you get my point...

[FMG_V6_btb]

Hello again, first of all let me apologize for maybe my lack of patience.

Thanks Remco for your soul, to slyalfa and Marcelo for their interest, thanks all.

So I will continue posting things, some will be more or less technical, and others in an understanding manner for everybody (I will try to attend any question), but I will like to receive some feedback.

I have said in others posts that I will need some help, especially measurements of the engine components, because my engine is still assembled and installed in the car due to the actual lack of free space in my workshop (other projects), so I hope some assistance in this subject.

Thanks for your understanding.

Paco.

[giuliettaevo]

Measuring is something i can do! depending on what you need to know offcourse... But otherwise i could always ask it on the dutch forum where i'm likely to get a fast and good answer.

[London_Alfa]

Quote:

Originally Posted by FMG_V6_btb Hello again, first of all let me apologize for maybe my lack of patience. Thanks Remco for your soul, to slyalfa and Marcelo for their interest, thanks all. So I will continue posting things, some will be more or less technical, and others in an understanding manner for everybody (I will try to attend any question), but I will like to receive some feedback. I have said in others posts that I will need some help, especially measurements of the engine components, because my engine is still assembled and installed in the car due to the actual lack of free space in my workshop (other projects), so I hope some assistance in this subject. Thanks for your understanding. Paco.

[FMG_V6_btb]

Hello!, following you can find two pictures with dimensions (well, letters), I would like to know that dimensions in order to design the piston crown shape and the outer diameter of the liner upper lip, also I need the volume displacement of the original piston dome (and valve pockets if possible), and the compression height of the piston.

Another issue, in the pictured head (3.7 SA version) you can see one external combustion chamber (cyl 1, 3, 4, or 5 I don't know), if you take a close look to the picture you will notice the marks produced by the liner (even the head was shaved!!), but the problem is that the marks are in the internal side of the combustion chamber, that makes me think that maybe the continuous heating and cooling of the head is little by little pushing the external liners to the external side of the engine, allowing a possible gasket failure around the external cylinders.

I have seen this phenomena in thermal shock tested engines with closed deck design, the difference is that the displacement happened to the metallic ring of the gasket.

Has somebody experienced gasket failures in the external cylinders?

Paco.

[FMG_V6_btb]

About cylinder head modifications... there are some critical issues to consider:
-Are the standard exhaust valves (sodium filled) stiff enough for that turbo application?
-It would be necessary to change the valve seat material, for bronze-beryllium or other?

I would like to maintain the original cams, so the decision about using mechanical shims depends of the weight of the valves I will finally use, and the rev limit (must to be analyzed).

I don't want to take too much material from the runners, so I just will enlarge a few and polish. The resulting difference compared to a highly modified port head in a turbo engine will be that the less modified engine will need a little more boost to achieve the same power, so I'm not sure if this worth.

One thing I'm sure I will do is improve the coolant flow from the block to the head.

Recommendations are welcome.

Paco.

[slyalfa]

OK I see now that the lines is a axel shaft not force lines. I have a new 24V in a box that I would like to do at some point. and I got a set of the THS rods to go with it. I have a SC that I was thinking of going with but I might go turbo or both. I would use the singel turbo ether way my self.

I have some 12V motors apart so I can do bottom end numbers/pics etc.

I was thinking a vett transaxel myself if I ever got that far.

[chelo]

I've always found that stainless valves work great on high performance engines. At least on american engines.