Hey Guys,
I love my 3.0 12V but I am considering a 24V conversion. From what i can see I know that, I will have to relocate the intake on the plennum, fabricate an oil sump, hopefully use the exhaust manifolds from the 24 and weld them on the original exhaust. Just wanted to ask if anybody has done it and if its worth it? Hopefully the engine mounts are the same. Thanks guys
Allan Goodall, long time member and brilliant racer and driver has done it. He is on the forum sometimes.
From how he drives, it is definitely worth it.
I've had two 24v engines now (3.0 & 3.2), that have been in my Alfetta GTV6. But Allan is the only I know who has done it in a 75 in Australia.
Quoteuse the exhaust manifolds from the 24 and weld them on the original exhaust
What's "24"? The 3.0 12v has round exhausts port. The 24v has oval exhaust ports, and will not fit so new extractors/headers are required.
EVO75 in melbourne has also done this conversion. You can do a search for his threads on the alfabb.com forum or youtube.
Yeah, alfabb.com, alfaromeo75.co.uk, and alfagtv6.com forums are worth having a browse to help your research.
Fitting the engine seems relatively straight forward. If you keep your 12V for parts, you can transfer some of the requirements (bell housing, etc); flywheel spacing needs to be addressed IIRC. Looks like fabrication is required for the alternator and PS pump brackets, and I've yet to confirm that an AC compressor can be fitted without major issues. Love or hate the various intake plenum options, but I'm not a fan of the 'purely cosmetic' appearance of the 24V plenum compared with the 12V. Then a matter of the electronics, brake booster (shape), and repositioning the oil filler cap. Unsure about exhaust manifolds.
What's your estimate on costs? I think it would cost me $5~6K for the conversion, including engine.
I would prefer the 12V with ITBs, but parts alone from a supplier like AHM in the UK would mount to $10K or so, so it would be double the cost.
:)
Are there not two versions of the 24v or is that the 3.0 vs the 3.2?
Quote from: aggie57 on March 15, 2013, 08:38:51 PM
Are there not two versions of the 24v or is that the 3.0 vs the 3.2?
Yes indeed. The 164 24v has the same oil pump arrangement as the 12v (auxiliary shaft driven from the cam belt), all later 24v engines- 156 2.5, all 3.2s and 3.0 found in Spider/GTV and 166 have a short internal chain driven from the front of the crankshaft. In the later 24vs the oil pump pick up is in a different position compared to the 12v and early 164 24v. The long and the short of it is that the RWD sump fits pretty well the early 24v and doesn't fit the later engines without cutting out some baffles in the upper half of the sump and re making the bottom half.
Many threads on the other forums about it
Scott
Thanks Guys for the great response. At this stage I just want to see the requirement for a project like this. I love the look of the 12V motor. I am either looking at upgrading the engine management system on my 12v, or removing the whole motor and replacing it with the 24V one. The Bosch L-Jetronic system is a bit old now...
Cheers
Alex
If you don't mind DIY, have a look at Megasquirt fuel injection
I have a great 164 24 valve motor available currently :)
Hi Alfamania, I'm in the process of a 24v swap myself, the sump is not a real issue, bit of fiddling but easy DIY, to use original 12v sump on 24v, I'm planning on running the full 24v belt arrangement, keep the later ps pump, ac comp and alternator.. No real dramas again just a few lines to move around. Main consideration is type of ecu, the later factory crank signal pick up is on the flywheel, sensor is bolted to sump, your old crank pulley wont fit as the sensor wheel fouls the water pump, easy to make a bracket to use old original sump with new sensor, I'm in the process of designing the spacer plate required for the flywheel to incorporate the crank trigger wheel, happy to share any info with you, engine mounts swap straight over, just need three shorter studs off the old engine for one side...
Thanks for the info guys. I just wanted to know what it involves to put a complete 24V engine in my Alfa 75? I wouldnt want to make a greatest hits out of the 12v and 24 V :)
Cheers
So do you mean that the 24V should go straight in an Alfa 75?
Alex, a 24v will not just go straight in, all the alfa 24v engines are east/west configuration. To mount one north/south you will need to borrow some bits from your 12v engine as well as swap out the ecu.
Ok so this is the way I see it:
Consider the 12V completely removed. I want to put a complete 24V in an Alfa 75:
Can I use 12V or 24V engine mounts for 24v to fit?
Do I need to do anything to 24v Sump to fit in Alfa 75 engine bay? or straight in?
Does the transaxle assembly fit straight on to 24V or do I need to use bits from the 12V?
I know I have to change the location of the plennum intake on the 24v so it fits from the side
Can I use the headers from the 24V and weld onto Alfa 75 exhaust? Will have to remove 12V headers
Why do I have to remove p.steer, air con alternator etc from the 24V? This stuff is already bolted onto the engine and seems there should be room anyway, is that right?
Thanks
Quote from: Alfamania on April 13, 2013, 08:28:31 AM
Ok so this is the way I see it:
Consider the 12V completely removed. I want to put a complete 24V in an Alfa 75:
Can I use 12V or 24V engine mounts for 24v to fit?
Do I need to do anything to 24v Sump to fit in Alfa 75 engine bay? or straight in?
Does the transaxle assembly fit straight on to 24V or do I need to use bits from the 12V?
I know I have to change the location of the plennum intake on the 24v so it fits from the side
Can I use the headers from the 24V and weld onto Alfa 75 exhaust? Will have to remove 12V headers
Why do I have to remove p.steer, air con alternator etc from the 24V? This stuff is already bolted onto the engine and seems there should be room anyway, is that right?
Thanks
The reason most of that stuff needs to change is because the engine you are staring with is packaged for an east west installation. You're putting it into a north south chassis.
If you have time it's really helpful to pull the 12valve and put it on the floor next to the 24v before you pull anything off either. That way the changes are obvious.
Someone else mentioned searching the alfabb for threads. Just search "alfabb 24v" from google and you'll get lots of hits on great threads about all this.
But don't let anything we say put you off. This is a great conversion, lots of people have done it and many of them have or are willing to share their experiences.
Quote from: Alfamania on April 13, 2013, 08:28:31 AM
Can I use 12V or 24V engine mounts for 24v to fit?
You can use the RWD engine mounts.
Quote from: Alfamania on April 13, 2013, 08:28:31 AM
Do I need to do anything to 24v Sump to fit in Alfa 75 engine bay? or straight in?
Did you see my reply further up the page? In short, you can't use the 24v sump, so you use a RWD one. How much modification that needs depends on which which 24v you have.
Quote from: Alfamania on April 13, 2013, 08:28:31 AM
Does the transaxle assembly fit straight on to 24V or do I need to use bits from the 12V?
You can use the RWD extension housing on the back of the block with whatever tail shaft your car had before. You will need to fit a 4mm spacer between the flywheel and the crankshaft.
Quote from: Alfamania on April 13, 2013, 08:28:31 AM
I know I have to change the location of the plennum intake on the 24v so it fits from the side
Yes, the throttle body on the 24v is rear facing on the right hand side and needs to be moved.
Quote from: Alfamania on April 13, 2013, 08:28:31 AM
Can I use the headers from the 24V and weld onto Alfa 75 exhaust? Will have to remove 12V headers
24v headers won't fit without serious modification. You could cut the tubes off the flanges and make your own extractors. 24v and 12v flanges are different and not interchangeable.
Quote from: Alfamania on April 13, 2013, 08:28:31 AM
Why do I have to remove p.steer, air con alternator etc from the 24V? This stuff is already bolted
onto the engine and seems there should be room anyway, is that right?
The PS pump does clear and is in the same spot as on the 12v. The alternator and AC compressor on the 12v mounts to the sump so if you were using the same mounts you would need to sort that out.
One other thing you might need to consider is the oil filter. I think at least some of the 24v oil filters screw onto a post that is part of a housing that is bolted to the block. There isn't room for this extra housing in the RWD setup so some blocks need to be tapped to take an oil filter post. There are pictures of this on the alfagtv6 forum
There are many, many threads on alfagtv6.com/bb with pictures. Some threads on alfabb.com too.
Scott