Boring out an '86 2.5 gtv6

[as-of-now]

Quote:

Originally Posted by AlfaTango1 Transverse or longitudinal it's still just an Alfa V6 with two heads on each side and a flywheel in back (or side in an fwd car). If you took the GTV6 or Milano intake plenum and swapped it with the 164 runners you could not tell the difference.

[as-of-now]

Quote:

Originally Posted by mjr Do yourself a favour, an email greg or ring him at the shop, you will get a million opinions on this forum, So talk to greg and get the facts from the horses mouth, then you can make a well informed decision, as to whether you want to boost, or go the 3.0 non boosted route.

[AlfaTango1]

It's the same as a 2.5 or 3.0 Verde engine once you pull it out. You just flip the whole engine 90 degrees and now it will be "normal' looking to you.

[as-of-now]

Quote:

Originally Posted by AlfaTango1 It's the same as a 2.5 or 3.0 Verde engine once you pull it out. You just flip the whole engine 90 degrees and now it will be "normal' looking to you.

[as-of-now]

and what about an LS? or is that in the same more complicated ballpark as a q?

[AlfaTango1]

An LS is the same as a Q other than having smaller diameter intake runners. They produce 210 vs. 230 hp for the Q.

[as-of-now]

Quote:

Originally Posted by AlfaTango1 An LS is the same as a Q other than having smaller diameter intake runners. They produce 210 vs. 230 hp for the Q.

[Gabor K.]

Why don´t you read the link I mentioned about putting the 3L 164 into the GTV6, it says all you want to know!

[Grant]

Dunno if this has been posted, but 3.5 liter 12V seems pretty healthy!

YouTube - alfa 75 schulze 3.5

[AvorioVeloce]

Quote:

Originally Posted by Gabor K. I think what you missed is that a big bore kit could be more expensive than a complete bigger engine. The less expensive way is to put in a bigger engine with some minor changes as cams and headers, that will give very good results. Boring up a block and installing new liners and pistons is very expensive and then you never can use original parts any more, totally dependent that the supplyer company keeps alive to supply the right spare parts. Big bore kits have been along since early nineties, supplied by Dieter Gleich, Germany and Sam van Lingen(SAVALI, Holland). Nowadays there is a company in UK that makes big bore kits for a price. But chances are you would be just as happy with a lightly tuned Alfa 75/164 3L 12V engine(200hp) or a 3L 24V 164 (210Hp), or even a 3,2 24V GTA engine with 250Hp. Here the link to AHM Motorsports, Alfa Romeo Bulletin Board & Forums

[bshorey]

Quote:

Originally Posted by Alfisto Steve It is my understanding the 3.2 or 3.5 conversion is for 3.0 24v engine not 12v 2.5 or 3.0 engines.

[scott.venables]

Have a look at:

Pro-Alfa Serious Alfa Romeo tuning and motorsport preparation

Scott

[Greg Gordon]

A big bore kit for the Alfa V6 is tricky. The real problem is boring the block to accept the larger liners. I don't have the facilities to do that. I can supply the pistons, rings, wrist pins and liners in whatever dimension the customer wants. All in all I consider forced induction to be a much better option.

Greg Gordon,
hiperformancestore.com

[junglejustice]

Not just that Greg - you have to heat-treat that block to stress-release it. I've talked extensively about this before guys (do a search for "seasoned block" and have a read!

[junglejustice]

Guys, I just saw this thread for the first time (and sorta have the "benefit" - or not - of reading it from start to end in one-sitting...) I must say; my head is SPINNING from all of the misinformation!

I can handle uninformed opinions (I too know little about many things, a great deal about only some things and what's needed about most topics - including my own limitations). But, the unbridled spouting and repeating of misinformation in this thread is just out of control, so I won't even begin to try and comment on it all!

I will advise getting the facts and comparisons straight on crank-horsepower, versus net wheel-horsepower and don't believe (and repeat) everything that you read on the internet!

For one thing, ALL of the Alfa V6 engines - going ALL of the way back to a carbureted 2.5 litre, 12 valve V6 Alfa Sei (Six) sedan - share the same blocks! Save for a few fins and untapped holes (and yes - oil-channels) here and there - dimensionally - the blocks are all identical (all of the way through the GTV6, Milano/75 V6, 164 12 valve, 164 24 valve, 156 24v, 166 24v and 147 24v generations of cars/engines)!

Every single one of ALL of these V6 blocks will sit right on the EXACT same V6 Milano/75/GTV6 engine-mounts and will take - WITHOUT modification - a standard transaxle tail-housing, V6 transaxle starter, transaxle flywheel with spacer and transaxle drive-shaft AND they will fit any Sei, Alfetta Coupe, Alfetta Sedan, Milano/75, GTV6 engine bay without issue or modification! Depending on the generation (12v or 24v), things up top are fine too! We have it pretty good with these conversions. With the 24v you just need to be in an ABS car, or change out the non-ABS pedal-box and booster, with an Alfetta pedal-box and booster and then the 24 valve fits easily!

Also, REGARDLESS of 12v or 24v, the big-bore conversions are the same for either generation of engine! You can do the same to either one! You do not "bore" these cylinders though - as mentioned! You bore the blocks to receive the larger cylinder-liners (bumping the bore from 88mm, or 93mm to 100mm) That gets you to 3.45 litres on a 74mm 3.0 crank for example! The longer stroke 78mm GTA crank gets you the other 200 CCs that you need to get to 3.7 litres, but the basic mods remain the same for 12 valve and 24 valve - regardless of whether you start with a 2.5 litre 12 valve block or a 24 valve 3.0 or "3.2" litre block. (Even the 3.2 litre GTA has "3.0" stamped on the block and most of the Glenwood 3.2, 3.45 and 3.7 litre conversions even start on 2.5 litre 24 valve cores!

My 3.45 litre 24 valve street 164 LS/Super is a 164 24 valve-based build and my 3.7 litre 24 valve full-race Milano/75 is 156 2.5 litre 24 valve-based! My street/track 3.0 liter 24 valve engine in the Milano Verde is also 164 24 valve-based!

Furthermore, you DO NOT have to align and limit yourself to the "stock is better" school of thinking when it comes to electronics! The standard 3.0 litre 164 LS 24 valve core with a mild inlet cam upgrade, larger GTA/Q intake runners and piggy-back fuel and ignition over standard Bosch Motronic, is capable of 260 horsepower at the crank and 212/214 of that at the wheels - still with the standard, restrictive, flapper-crapper AFM in place! With fully-programmable, stand-alone engine management, the AFM removed, custom headers and proper exhaust and intake, that number jumps to 270 or so at the crank with 218 to 220 of that making it to the wheels!

A 3K "bolt-on" supercharger kit does not address the cost, or time, or effort to install the kit! Water-injection, shipping, relay-kits, connectors and various other bits and pieces needed to sort the car are also not part of the game. MOST important of all - true, programmable fuel and timing management that will be essential to the comparative equation is not included either! So add at least another 2K to that 3K number when it is all said and done (at least if you want to see the numbers quoted and want do so reliably)!

Also, remember that your entire setup is now based on a 25-30 year-old, stock 2.5 litre or 3.0 litre 12 valve engine with stock rods, stock pistons, stock push-rod rockers, stock old rings etc etc. If you really want to compare this "low-cost" "bolt-on" option to a 10,000 dollar rebuilt and converted, turn-key, naturally-aspirated engine (and be fair about it), you really should toss a 5-7K dollar rebuild ON TOP of that 5K number... Now you're at 10-12K already - new, rebuilt, performance 3.2 litre 24 valve territory (and very close to new rebuilt 3.45 litre 24 territory)!

Last thing; for those of you who think that you simply "just throw in" a 1,000 or 2,500 dollar 24v core in the transaxle from a 164 - think again! No - there are not any "scrap pieces" to buy to make it a "drop-in" either! There's conversion to the sump, oil-pump, oil-pump pick-up, flywheel and bolts, custom headers, valve-cover mods (if you don't have ABS), intake plenum TIG-welding, removal of MANY studs, conversion of the t-stat-housing and electrical to sort! Oh, yeah - then it will drop in - takes about 7 minutes with 2-3 guys - done! Then what!? Now comes the custom bracket fabrication to fit the ancillaries, sorting of vacuum, hydraulic hoses for P/S and A/C for example and the electronics!

At the end of the day the 3K bolt-on S/C kit is a good value, but not a good camparison as-is to new, rebuilt 24v conversions. What I'd really like to see is one of our 24 valve builds, with one of Greg's S/C kist on there!