Alfa romeo v8 engine

74Spider
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Alfa romeo v8 engine

Post by 74Spider » Sun Jun 13, 2010 1:03 pm

Hi All, :D

My first post to this forum and from what I've seen just looking over the pages, I've come to the right place!!

Short story - I want to obtain an Alfa V8 engine for a replica project. Due to low availability of Alfa V8 units, I'm currently looking into something that has been done with other units, and that is to produce a V8 from 2 straight 4's.

My goal engin at the end of the day is as close as possible to the following spec:

Alfa original parts
90° V8
DOHC
Twin spark
6 speed manual RWD (maybe 911 or Audi transaxle)
For longi mid mount
Modern EFI system is OK
Over-square - 52mm stroke, 80mm dia cylinders

If you make a bespoke block, crank and conrods I guess its definitely possible, but can anyone come up with a decent reason why this cannot be done using all Alfa original parts ?

So far I have accepted that I need to make bespoke conn rods.

Thoughts/comments appreciated.

Great forum!

Cheers,

Paul.
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Re: Alfa romeo v8 engine

Post by Giuliettaevo2 » Sun Jun 13, 2010 2:16 pm

when you would use two Nord heads for your v8 engine you would have to change one of the heads drastically... the intake and exhaust side should be changed so that on the v8 engine the intake is in the middle of the two banks and the exhaust is on the outside of the engine.

If you can make that happen then i can see you building a new Alfa v8.. :oops:

But if you consider the costs of making a crank, conrods and engine block i can't see why you would want to do this... buying a Montreal engine must be cheaper than that. :?
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Re: Alfa romeo v8 engine

Post by la_strega_nera » Sun Jun 13, 2010 4:02 pm

74Spider wrote:Hi All, :D

My first post to this forum and from what I've seen just looking over the pages, I've come to the right place!!

Short story - I want to obtain an Alfa V8 engine for a replica project. Due to low availability of Alfa V8 units, I'm currently looking into something that has been done with other units, and that is to produce a V8 from 2 straight 4's.

My goal engin at the end of the day is as close as possible to the following spec:

Alfa original parts
90° V8
DOHC
Twin spark
6 speed manual RWD (maybe 911 or Audi transaxle)
For longi mid mount
Modern EFI system is OK
Over-square - 52mm stroke, 80mm dia cylinders

If you make a bespoke block, crank and conrods I guess its definitely possible, but can anyone come up with a decent reason why this cannot be done using all Alfa original parts ?

So far I have accepted that I need to make bespoke conn rods.

Thoughts/comments appreciated.

Great forum!

Cheers,

Paul.
For what it's going to cost, you might aswell just buy a F360 Engine and box - they can be had for circa 9-10,000 usd.
I'm guessing it's a Tipo33 of some description?
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Re: Alfa romeo v8 engine

Post by Greg Gordon » Sun Jun 13, 2010 5:20 pm

It would be very difficult and expensive. Most people think a V8 is two inline 4cylinders together. It's not, it's four V2s together. This project will involve a whole new block and crank and a lot more.

I agree it would be cheaper and probably a lot better to get a Ferrari or Maserati V8, or perhaps a really hot Alfa V6. If it's an Alfa replica I would go with the later.

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Re: Alfa romeo v8 engine

Post by 74Spider » Mon Jun 14, 2010 12:27 pm

Hi Gents,

Thanks to you all for taking time to put your thoughts down.

Some replies:

Giuliettaevo2: My proposal would be to run one of the engines in reverse and swap the inlet/exhaust banks. Like you say, the head would ideally need some mods (valve sizes etc) but, with the right timing, I'm not aware of any reason why you can't run a stock head in reverse if you mate the inlet/exhaust to the opposite sides of the head. My thinking is that the resulting engine will be a decent capacity of 3 to 4 litres so the rough target of 230bhp shouldn't be hard to achieve, even if you run one head with the smaller valves on the inlet side. I haven't looked into it in detail, but I guess it would be possible to swap the valve seats. I'm hoping that the crank centreline lies on the centreline of the cylinder bores - but I'm not sure of this as yet.

la_strega_nera: Like all things Alfa, this is strictly a 'heart over head' project. You're totally right to say it makes better financial sense to drop in an existing V8 lump and that would give a tried and tested/more robust engine in the long run. Thing is, if there is a way to open up the hood of this bad boy (purely on paper so far) and see all Alfa underneath, then that's got to be the first target. Ye sit is a Tipo 33 replica.

Greg: Again, I agree with everything you say, but I know what a V8 is. I'm not aware that Alfa made any V2s ! I toyed with the idea of 2 Lancia V4s but they seem to be as rare as Montreal engines. Someone made a good comment in another forum that Montreal engines should be kept for Montreals and I agree. Not my favorite Alfa by far but I take the point.

Sure there are more sensible ways of getting a V8 lump for a replica but, if at all possible, I want Alfa power! Don't we all ?

Heart over head.

Thanks again for your input.

Paul.
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Re: Alfa romeo v8 engine

Post by MD » Mon Jun 14, 2010 1:48 pm

Paul

It's all been done before. At the end of the day, the Montreal is just two Nord blocks banged together to make the so called V8 engine (in a manner of speaking),. :wall: That is why it has the weird firing order. So a close examination of this engine gets you to where you want to go. Of course it's only 2.5 litre so why would you want to build one when you can buy one?

It' not 4 litres is it ?? ...

I like to see engineering challenges come good. I wish you well and I certainly understand your motivation.
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Re: Alfa romeo v8 engine

Post by Duk » Mon Jun 14, 2010 5:49 pm

To use a pair of NORD heads, you could either weld up the inlet ports on left side head (looking at the front) to shrink them so they are more of an exhaust port size. And port the exhaust ports to they are the same size as the inlet ports. Massive amount of work and success couldn't be guaranteed because of the amount of heat put into the casting (stresses). Then there is the work required for the valve seats.

Another idea would be have a chain drive for the left side head at the back of the engine. That way the left side head could be just a standard NORD head put on backwards.

How would you make the block???

I'm thinking fabricated from plate and billet, welded together, stress relieved and machined for crank and cylinder bores and oil galleries and coolant passages.

Massive amounts of work and money either way.

Toyota made a beautiful, solid, DOHC 32 valve aluminium V8 that would cost a fraction of what you're proposing.
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Re: Alfa romeo v8 engine

Post by Mats » Mon Jun 14, 2010 11:21 pm

I don't know what to say without sounding like a complete bastard. :shock:

I just agree with the guys above. Too much work and not really anything to show at the end of the day except a mongrel of an engine.
At least go for the Lampredi 16v (which was actually sold in the 155 Q4 and used in the BTCC cars), it has almost symmetrical heads front to back, you need to rework a bit around the "front" of the cams on the reversed head but it's nothing compared to what you would have to do on a Nord/TS.
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Re: Alfa romeo v8 engine

Post by Duk » Mon Jun 14, 2010 11:57 pm

Mats wrote:I don't know what to say without sounding like a complete bastard. :shock:

I just agree with the guys above. Too much work and not really anything to show at the end of the day except a mongrel of an engine.
At least go for the Lampredi 16v (which was actually sold in the 155 Q4 and used in the BTCC cars), it has almost symmetrical heads front to back, you need to rework a bit around the "front" of the cams on the reversed head but it's nothing compared to what you would have to do on a Nord/TS.
Harsh Mats, bloody harsh! :P :P :P :P



:lol:
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Re: Alfa romeo v8 engine

Post by Greg Gordon » Tue Jun 15, 2010 6:43 am

What about adding two cylinders to the V6? Still a lot of work, but I think it would be easier.
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Re: Alfa romeo v8 engine

Post by Mats » Tue Jun 15, 2010 7:40 am

what about a straight eight? Or a boxer eight? Just mating a few engines... :D
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Re: Alfa romeo v8 engine

Post by 74Spider » Tue Jun 15, 2010 10:40 am

Thanks again for the input Guys. All comments are really appreciated. Quick reply to each below:

Mats: I love the boxer and it would make a great flat 8, but its a replica V8 I'm after for this particular project.

Greg: Adding 2 cylinders to a V6 would present balance issues cos of the 60°/8 cylinder conflict. The Alfa V6 unit may be a 2nd choice if the V8 doesn't come off but that would present its own mating issues: FWD transverse versus mid-engined, longitudinal RWD.

Mats: I'm not familiar with the Lampredi, but I'll check it out thanks. Sounds like it may rule itself out financially too though.

Duk: You've given this some thought! Sensible decision would be a Toyota or Lexus V8. It could proobably be cosmetically modified to appear more like the Alfa unit for a replica.

MD: The Montreal has the 90° crank opposed to the straight crank of the 33 units (and the straight 4 lumps), and a much longer stroke which detracted from the power compared to the 33 V8. The 3.2 to 4 litre comes from combining two 1.6, 1.8 or 2.0 litre engines - but I would want to shorten the stroke if possible so that would reduce somewhat - probably closer to 3 litres. It should scream! Thanks for the encouragement.

Appreciate your thoughts Guys - nothing to write me off just yet!!!

:lol:
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Re: Alfa romeo v8 engine

Post by Mats » Tue Jun 15, 2010 12:49 pm

Lampredi = Fiat 8/16v engine.

The price is a factor for you? Seriously? 8)

ToDo:
-Crank
-Rods
-Block
-Cams
-Flywheel/pulley
-Figure out how to balance the engine when one bank is limping along due to massive flow imbalance when using 40mm inlets and 44mm exhausts plus the port geometry.

Not to mention:
-Design a cooling strategy.
-Design a lubrication strategy
-Figure out how to balance it


There is quite a lot of CAE involved in the block design...
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Re: Alfa romeo v8 engine

Post by xrad » Tue Jun 15, 2010 1:03 pm

74spider:
I see the montreal engines/heads pop up on ebay every 6 months or so. I am sure you will find one unless you are in a rush. I think there is a guy up in Washington state USA who has hoarded a few examples..

I have even seen the whole Montreal in "kit" form (all in boxes) for very reasonable price. Then you can take what you need.

As far as transmissions, I would suggest T5 world class(cheap, light, durable, and parts and sizes are many) with front bell housing/ clutch/adaptor made up to suit..and then you can do almost anything for the rear.
Last edited by xrad on Wed Jun 16, 2010 3:18 pm, edited 1 time in total.
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Re: Alfa romeo v8 engine

Post by 74Spider » Tue Jun 15, 2010 1:59 pm

Mats if that's all there is to do then I would be very happy! I don't think the valve size issue would be massive, but valves/seats are something that can be addressed if they prove problematic. Firing orders differ by manufacturer, but I'm guessing you can impose an order that alternates between banks to smooth out any imbalance.

xrad: Thanks. I saw a Montreal engine on ebay a couple of months ago. I was watching it and it just disappeared without trace. Obviously the guy was nobbled into selling it off line! Thanks for the gearbox suggestion.

Getting back to my original question: "why it cannot be done", I'm not hearing anything drastic so far. I think bottom line is that it is worth pursuing, at least with enough confidence to give it a bash, and let the flow/test bench show how successfull/unsuccessfull it turns out.

Thanks for the input and encouragement ! :D
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