12v vs 24v

Started by BradGTV, August 19, 2012, 06:07:24 PM

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BradGTV

slowly starting to convert my 164 3 ltr to rwd, drained oil / pulled sump off and shes full of milky sludge.... (pretty safe to say headgasket?)

yesterday i went and bought some parts (scored gtv/spider 4 pot brembo calipers for $50 each :D) the guy also has a 3.0 24v engine that has been in an engine fire but hes selling it for scrape value, am i right in saying that it would only require all new gaskets and seals? no need for bearings? (engine has done 120thou k's)

is it worth me getting the 24 valver and replacing all seals and gaskets and go through with a 24v conversion in my gtv6 (i am aware of the extra hassles) for much gain over the 12v 3.0 (with new headgaskets)? has anyone got an opinion of what the 24v engine are like power, economy, torque curve ect.. compared to the 12v ?

ill will be running aftermarket FI on either engine
79 gtv sr20, 83 gtv, 83 gtv6 3.0, 75 ts x 3, 85 gtv, 76 gt, 91 164, Subey L Series, S13 silvia, Bmw e30 318i, VT SS 6spd

julianB

From memory, the 24v torque peak is a bit higher up the rev range- solution? Run it with TS transaxle (4.1 diff). An ECU and extractors/exhaust will give you a 7k rpm engine that eats a 12v.

But if the 12v is easy to get your hands on, they'll sing nicely too
85 GTV6 "Juliet"
GTA conversion-
AHM ITB setup, Jim K manifolds & 10.3 cams, M84
17" Work Meister S1R
330mm Brembo front, vented rears
RS coilovers and bits
Recaro LX mesh headrest buckets

'68 step nose Junior "Romeo"
bare metal project

julianB

And just realised its a 916 donk- it's a lot of work to fit- i'd stay 12v and go big bore or blown if you're serious!
85 GTV6 "Juliet"
GTA conversion-
AHM ITB setup, Jim K manifolds & 10.3 cams, M84
17" Work Meister S1R
330mm Brembo front, vented rears
RS coilovers and bits
Recaro LX mesh headrest buckets

'68 step nose Junior "Romeo"
bare metal project

BradGTV

thanks julian,
kevin on the gtv6 board has a breif write up of whats required. nothing there isnt hard to do. most time consumming will be making the extractors and full exhaust system.

does anyone know if the alfa 164 24v engines use the same gasket / seals as the 916 gtv / spider 24v engines?

im also looking for the plastic timming belt cover, anyone have one or know where i could get one?
cheers, Brad
79 gtv sr20, 83 gtv, 83 gtv6 3.0, 75 ts x 3, 85 gtv, 76 gt, 91 164, Subey L Series, S13 silvia, Bmw e30 318i, VT SS 6spd

L4OMEO

Hey Brad

Interesting project there.

Just some feedback on the 12V v 24v engines - when in NZ I drove a 12v 164Q back-to-back with a 24v 164Q and couldn't believe the difference between them in terms of character. The 12v was smooth, refined, sounded amazing, and had a very linear power delivery. The 24v was a very different beast with a huge hole in the torque curve in the low to mid range (typical of old-school multi-valve engines) but from around 4k it erupted and became a monster. At the top end it definitely had more punch than the 12v but was unquestionably having to make up ground following that poor mid-range. I had a Merc 190E 2.5/16v Cosworth at the time and it had more punch low down, and until I drove the 24v 164Q I had thought THAT was poor!

The noise the 24v made dominated the car, sounding almost like an angry and bellowing Italian V8 rather than a howling V6. While intoxicating and genuinely exciting, switching back to the 12v only showed how much sweeter and more refined that engine was.

For the record the 12v I drove was rumoured by one person I spoke with to have been chipped although that was disputed by another party, while the 24v was the Alfa Romeo NZ press car and therefore standard but in fine fettle.

Fantastic cars both, no question. But, as I started off by saying, the engines are very different in character so depending on what you were planning to create might influence which one would be your preference. The thought of that 24v in a road/track GTV6 ... mmmmmm .....

Cheers Brad
Rory

PS no I didn't get a chance to test the fuel economy ...
2002 156 GTA