Alfa Romeo Forums banner

1 - 20 of 63 Posts

·
Registered
Joined
·
606 Posts
Discussion Starter #1
With a 76 Alfetta GT, all smogged down in California, sometimes you wish for more power, options on 2.0 Twin Cam?

1) Turbo
2) Supercharge
3) 2.5 GTV6
4) 3.0 Milano
5) V-8 Montreal
6) Other?

Weight, balance, reliablility for road use?

ncng
 

·
Premium Member
Joined
·
886 Posts
i am in the middle of a v6 swap and it is more work, lots more money than it would seem to take. my money would be on greg gordon's nord supercharger kit he is developing. if it were available when i started mine, i may have gone that way.
 

·
Registered
Joined
·
3,887 Posts
Twin spark?

With a 76 Alfetta GT, all smogged down in California, sometimes you wish for more power, options on 2.0 Twin Cam?

1) Turbo
2) Supercharge
3) 2.5 GTV6
4) 3.0 Milano
5) V-8 Montreal
6) Other?

Weight, balance, reliablility for road use?

ncng
 

·
Registered
Joined
·
390 Posts
bolt in. you will only need to sort out a efi pump. flywheel, starter, bellhousing, engine mounts are all the same as a nord ;)
 

·
Registered
Joined
·
606 Posts
Discussion Starter #6
Any particular year TS better then another? What did you use for efi pump, flywheel and starter? Please explain bellhousing problem, make adapter?

How much better is end result?

ncng

bolt in. you will only need to sort out a efi pump. flywheel, starter, bellhousing, engine mounts are all the same as a nord ;)
 

·
Registered
Joined
·
4,501 Posts
You left off one important and very effective option in your initial considerations - a 24v conversion from a 164, 156, 166, or 147!

Lots of cores available and right out of the box you are at 210 horses minimum! With the Q / GTA 44mm intake runners you are rated by the factory at 220 horses (230 for the European motors with the pass-through MAS-type air meters) and with simple inlet cam upgrades you are up to 260 horses on the stock ignition (212 / 213 / 214 at the wheels!) Add a fully-programmable stand-alone engine management system to help optimize the cams, the custom headers, custom intakes and custom exhaust and now you're up to 270 horses with a real honest 215 - 220 at the wheels!

Lots of scalability before ever even opening the motor up!

With a 12v Milano Verde 3.0, or a 12v 164 swap and cams, THE MOST you will ever see without opening the engine up is MAYBE 210 horses at the crank with around 170-180 at the wheels! A built 12v 3.0 may someday get you to 220 at the wheels. If you go the 24v route and decided to utilize the GoTech programmable system, I have a variety of pretty smooth maps available via a simple email! 24 valve donour cars are getting pretty cheap and I have seen motors trade hands at very favorable prices as of late!

Either way, on a standard rebuild you can bump compression fairly easily and cost-effective - all things considered - and eventually go big-bore; a 3.2 litre (with stock parts available from Alfa Romeo), or 3.45 to 3.7 litres from tuners like Glenwood Motors! Then you get to single turbo and twin turbo options on top all of the options mentioned above, so the sky's the limit! Tail-housings & mount and the front engine mounts bolt right up and sit right on the stock mounting points! Starter, flywheel and cooling system is a direct bolt-on! Custom headers and intake mods are readily available and the sump and oil-pump modifications are a known factor!

Naturally the big-bore displacement options are available for 12v cores as well. The 12v will have more torque at lower rpms than the 24v however, the devil is in the details – the 24 valve’s peak torque is always higher than the 12 valver’s peak torque – albeit at a slightly higher rpm. At 3K to 3500 rpm when the 12v has peaked, the 24v is just starting to come alive!
 

·
Registered
Joined
·
390 Posts
sorry i should have worded it better. the twinspark from a milano/75 is basically the same block as a nord. they share the same engine mounts, bellhousing, flywheel.

making it very easy conversion, the only mods to your excisting car is mounting the ecu under the dash, mounting the coil's in the engine bay and putting a 'drop' tank on your excisting fuel tank or install a swirlpot/surge tank.

just use the standard 75 pump.
 

·
Registered
Joined
·
4,090 Posts
IMO the increase from a 2.0 Nord to a 2.0 Nord TS is not a lot - maybe 20 HP on paper. Driveability may be better, but if you go through the trouble of an engine swab I would personally aim higher, at least 3.0 V6 - either out of a Milano, 164S (Motronic, higher compression), or 24v out of 164 LS or Q. A junk-yard late style Milano 2.5 V6 will probably give you the parts needed to convert a 164S engine. I put a 164S engine in my Milano race car - the conversion is documented in the Roxanne thread.
Jes
 

·
Registered
Joined
·
2,909 Posts
Naturally the big-bore displacement options are available for 12v cores as well. The 12v will have more torque at lower rpms than the 24v however, the devil is in the details – the 24 valve’s peak torque is always higher than the 12 valver’s peak torque – albeit at a slightly higher rpm. At 3K to 3500 rpm when the 12v has peaked, the 24v is just starting to come alive!
Obviously you prefer the 24V valver over the 12 valver and forgot to check your data JJ!
The torque cuves of the 12V is not as bad as you write here! Or did you get some real bad cars over there? Let me quote the torque peaks for different 12V engines:

Model 75 4000 rpm / 245 Nm.........185 Hp / 5800 rpm

Model 75QV 4500 rpm / 250 Nm.......192 Hp / 6000 rpm

Model SZ 4500 rpm / 245 Nm.........210 HP / 6200 rpm

Compared with the 24V engines

164 Super 24V 5000 rpm /270 Nm.....210 Hp / 6300 rpm

164 Super QV 5000 rpm /280 Nm......230 Hp / 6300 rpm (a slightly tuned

version of the Super, by other inlet and outlet.)

Comparing 3L 12V and 3L 24V does not show such a big difference, and as said earlier a 12V can easily be tuned to get better data than a standard 24V. Of course putting all your money in a 24V will win the Hp race in the long run, but the difference is not so radical.
For a regular person a tuned 12V engine is a good deal moneywise, its easy to install without a lot of modifications, and a lot easyer to get approval from transportation authorities- it looks original.
Comparing data with a known slightly tuned engine 3L 12V and the factory data for the 164 Super 24V, the 12V gave a few more Hp all over, much better torque all over and it has 30 Hp more than the 24V engine at 2500 rpm! Still it goes to 6500 rpm.

So please have a little more respect for the 12V engine! I love both 24V and 12V engines, but would not change my 12V 3L with a 24V 3L, so I will change to 3,2L 24V to get more grunt! :)

G.K.
 

·
Richard Jemison
Joined
·
7,697 Posts
Re-powering an Alfetta

I have to agree with Jes and G.K. that converting an Alfetta from a normal "Nord" type 2 liter to anything else needs some serious thought.

The 2 liter "Nord" is easily made into a very streetable 165+ HP & Torque motor using factory parts with proper mods and cams.

The simple swap for more displacement is the V6 12 V motors, again which can be easily made into 250HP and more (275-300 HP 3.0 motors are common) with factory parts, and proper mods which are both cheap and readily available.

Unlike both the TS and V6 24V motors, which in the case of the TS lacks readily available parts in the USA, and really isn`t any more capable than the Nord. It`s power increases due to modern cam designs, not so much head differences.

The 24 V V6 motors are infinately more complex to work with and performance mods are much harder to find. I would never suggest using a 24 V as a performance swap over a same displacement 12V for ease of gaining HP/Tq.

Dropping a V6 from a Milano is simple, with a driveshaft shortening the most technical....

To me the reliability, lack of technical complexity makes Turbos and 24Vs just unreasonable compared to the Simple solutions.:p
 

·
Registered
Joined
·
390 Posts
richard im interested what mods you suggest, can get a 3.0 12v up to 275-300 hp on standard parts? i will be doing, headers, exhaust, aftermarket ecu. what else do you suggest to get those power levels?

i personally have decided to use a 164 3.0 engine in my gtv6 as a daily, and the track car will have a twinspark with a t28 turbo. the handling of the 4cyl is deffiantly noticeble over the v6, but less power, it all depends what you want to do with the car.
 

·
Registered
Joined
·
2,731 Posts
The 2 liter "Nord" is easily made into a very streetable 165+ HP & Torque motor using factory parts with proper mods and cams.
Richard, this has me interested for the 2L engine for my GT Veloce. What is your 'simple' formula of components that would need to be upgraded? I tried to search your posts in other threads but due to your prolific generosity in sharing your knowledge I found it a bit overwhelming!:eek: Is there a thread you can recall that covers this already?
 

·
Richard Jemison
Joined
·
7,697 Posts
Performance Mods

Richard, this has me interested for the 2L engine for my GT Veloce. What is your 'simple' formula of components that would need to be upgraded? I tried to search your posts in other threads but due to your prolific generosity in sharing your knowledge I found it a bit overwhelming! Is there a thread you can recall that covers this already?

BradGTV richard im interested what mods you suggest, can get a 3.0 12v up to 275-300 hp on standard parts? i will be doing, headers, exhaust, aftermarket ecu. what else do you suggest to get those power levels?
Here are the basics for either motor:

1- Head prep. Don`t ask for my specifics!
Proper porting with correct bowl and seat design. This is critical. Large valves are un-necessary and in fact interfere with flow. Standard size valves flow better and weigh less. They should be re-shaped for flow.

Heads should be milled for compression increase. With (Nord) 10.0 Motronic pistons with the sides of the valve reliefs opened and tapered, Milling the head .040 will result in 10.75 to one which runs fine on premium fuel. A nord head can be cut .060 safely..for higher compression.

3.0 V6 heads using "S" 10.0 pistons can be cut as much as .060 But for premium fuel I suggest only .040 with piston valve reliefs opened to the sides another .040 and tapered to clear the sides of the valves.

Piston valve reliefs on either V6 or 4 cyl can be cut up to .050 "deeper" but this reduces compression. This is not necessary with correct valve timing (built into my V6 cams) but the side of the pockets must be opened with heads cut more than .020.

2- Intake:
It is necessary to match runners with ported heads. Critical on V6 as it is a sloppy mess from the facrory. Runners on V6 should not be opened up more than 36mm. This is using Milano/GTV6 type with shorter runners. 164 type are too long, designed for street torque improvement. Inside of the plenum on V6 should be opened and smothed so air can flow from TB forward and rearward with no obstructions.
Programable FI with larger injectors are necessary. Facttory FI with proper cams can only supply fuel for about 200-210 HP.

2L Nords will need manifolds ported to match 45mm Webers tapering to match to the heads. I do not suggest using anything other than the factory airbox opened to 50MM to match inlets of the 45 DCOE Webers. Air horns increase the runner length way too much.

3-Cams:
These are the brain of the engine. There are intake lobe designs and there are exhaust lobe designs. You will never make the engines optimal power without correct cams. Alfa originally used the same cams intake and exhaust only because of cost & simplicity. Many of my customers have posted results showing improvements off the shelf cams. Correct cams built to match engine and it`s mods will produce far more Torque (that is the critical measure) and far more HP.

V6 cams are complicated devices and must be built to fit application. The intake lobe, design. and position(LCs, LSAs) must be taylored to the engine in order to fit, and work (timed) correctly. As well the exhaust lobe must be the correct design and timed correctly to maximize the power stroke and live comfortably with fragile rockers. (I suggest using the later 164 I-Beam rockers) You will need adjustable cam sprockets to time cams correctly after cutting heads or with any large lobe cam.

Here`s some related threads that have useful info in them somewhere:

http://www.alfabb.com/bb/forums/engine-rebuilding/149753-good-setup-built-2-liter-motors.html

http://www.alfabb.com/bb/forums/other-italian-cars/137236-ferrari-p4-build-thread.html

http://www.alfabb.com/bb/forums/engine-management/149989-some-rjr-camshaft-profiles-other-cam-profiles.html

http://www.alfabb.com/bb/forums/engine-management/149989-some-rjr-camshaft-profiles-other-cam-profiles.html

http://www.alfabb.com/bb/forums/engine-management/65790-123ignition-revisited.html

http://www.alfabb.com/bb/forums/carburetors-fuel-injection/151959-weber-40s-45s.html

Untitled Document

http://www.alfabb.com/bb/forums/giulietta-giulia-1954-65/36462-install-2-l-into-giulietta-spider.html

http://www.alfabb.com/bb/forums/motorsports/146536-air-intake-webers-105-track-car.html

http://www.alfabb.com/bb/forums/engine-rebuilding/162968-165-hp-engine-recipe.html

http://www.alfabb.com/bb/forums/alfa-romeo-parts-sale-wanted/151512-adjustable-cam-sprockets-v6-12v.html

http://www.alfabb.com/bb/forums/spider-1966-up/74007-spider-improvement-effort.html
 

·
Registered
Joined
·
4,501 Posts
The 12v will have more torque at lower rpms than the 24v however, the devil is in the details – the 24 valve’s peak torque is always higher than the 12 valver’s peak torque – albeit at a slightly higher rpm.
The point was for those who believe (incorrectly so), that “…the 12 valve has more torque…” – an internet rumor consistently repeated here in error…!

Obviously you prefer the 24V valver over the 12 valver and forgot to check your data JJ! The torque cuves of the 12V is not as bad as you write here! Or did you get some real bad cars over there? Let me quote the torque peaks for different 12V engines:

Model 75 4000 rpm / 245 Nm.........185 Hp / 5800 rpm
Model 75QV 4500 rpm / 250 Nm.......192 Hp / 6000 rpm
Model SZ 4500 rpm / 245 Nm.........210 HP / 6200 rpm

Compared with the 24V engines

164 Super 24V 5000 rpm /270 Nm.....210 Hp / 6300 rpm
164 Super QV 5000 rpm /280 Nm......230 Hp / 6300 rpm (a slightly tuned version of the Super, by other inlet and outlet.)
Thanks for posting these numbers; it confirms my point!

Still, there are those around here who always want to make the case that the 12v has more torque than the 24v; it is just not true. It simply has its peak torque at lower rpms, but even at that point – in the real world on the same dyno back to back – the 24v has more torque at that rpm point… Regardless of the numbers though, you DRIVE the 12v and you get the sense at 4K rpm that it is all over (from the butt-dyno!) At 5K to 5500 rpm you shift and it is commonly known that at 6K a STANDARD 12v has nothing left!

Now, a built 12v motor with headwork, higher compression and radical cams will pull strong all the way up to 7K with a nice flat torque curve however, given the SAME mods to a 24 valve, you’ve just moved that motor light-years ahead, yet again. You can’t gain on it with apples to apples mods! And by the way, my 24v 3.7 makes 90% of its peak torque at 2500 rpm, so you DON’T have to rev the bearings out of the block to make it happen in a 24v either!
 

·
Registered
Joined
·
4,501 Posts
The 24 V V6 motors are infinately more complex to work with and performance mods are much harder to find.
This is ABSOLUTELY incorrect! Just because YOU haven’t tried the conversion, or tried modifying a 24v dick, doesn’t mean that they are “complex” (and parts are just as easy to locate as for the 12 valve!) Setting the timing on a 24v for example is a GREAT DEAL MORE intuitive than on a 12v (and much more flexible with the INFINITELY variable cam-gear set-up of the 24v!!!) Just one example.

To me the reliability, lack of technical complexity makes Turbos and 24Vs just unreasonable compared to the Simple solutions.:p
Simple solution if 140-150-160 horsepower at the wheels is your goal.

Dick, I can’t believe that you would consider your own comments with regards to “hard to find performance modifications” credible – given the vast range of options and NOTABLE success from big-bore tuners like AHMotorsports, Glenwood Motors, Savali and Autodelta in the UK…!!!??? Those guys have all been at it for 20-30 years now! I myself have made a market for many folks States-side in cams, headers, engine management systems, intakes and turn-key big-bore conversions for over 7 years now!

IAP, Centerline, APE and your friendly local Alfa Romeo / Fiat / Ferrari dealer - ALL sell 24v parts!

Ring up Jason at Alfissimo here in the US for example and ask him for a gasket, or a pulley, or a belt, or a tensioner, or whatever “for a 164” and the automatic question comes – “…12v or 24v…” - he even stocks most fast movers!

The simple swap for more displacement is the V6 12 V motors, again which can be easily made into 250HP and more (275-300 HP 3.0 motors are common) with factory parts,
I agree that that 12v V6 swap is relatively simple, but show me ONE with "factory parts" that makes 250 horses!

"...easily made into 250HP..." !? With a high compression rebuild and aggressive cams perhaps!

"...275-300 HP motors are common..." Show me ONE 12v with anything less than 11:1 compression and a streetable cam that makes 300 horses dick!

In fact, just show me ONE real-world naturally aspirated 12 valve 3.0 Alfa V6 with ANY compression and ANY cams that makes 300 horses on pump-gas! Period. I'll pay for the dyno time! You're selling a dream dick!
 

·
Registered
Joined
·
2,909 Posts
The point was for those who believe (incorrectly so), that “…the 12 valve has more torque…” – an internet rumor consistently repeated here in error…!



Thanks for posting these numbers; it confirms my point!

Still, there are those around here who always want to make the case that the 12v has more torque than the 24v; it is just not true. It simply has its peak torque at lower rpms, but even at that point – in the real world on the same dyno back to back – the 24v has more torque at that rpm point… Regardless of the numbers though, you DRIVE the 12v and you get the sense at 4K rpm that it is all over (from the butt-dyno!) At 5K to 5500 rpm you shift and it is commonly known that at 6K a STANDARD 12v has nothing left!

Now, a built 12v motor with headwork, higher compression and radical cams will pull strong all the way up to 7K with a nice flat torque curve however, given the SAME mods to a 24 valve, you’ve just moved that motor light-years ahead, yet again. You can’t gain on it with apples to apples mods! And by the way, my 24v 3.7 makes 90% of its peak torque at 2500 rpm, so you DON’T have to rev the bearings out of the block to make it happen in a 24v either!
I actually agree with most of the above, but I reacted that you mentioned that the 12V 3L engine, the torque peaked 3K-3,5K, whileas it actually peaks 4K-4,5K which is quite different.

Also my case is using a slightly tuned 3L 12V instead of a standard 3L 24V. Under that condition you could have equal power but more torque from the 12V. And driveability!
About the rpm shyness of the 12V can be said its easily corrected by inserting SZ cams and SZ/CSC/Supersprint/PS-Shulze headers with sport exhaust. With just this mod the engine goes to 7K rpm! No hesitation in rpm increase at all! Pure fun to drive!

About 300 Hp from a slighly tuned 3L 12V, I dont believe it either, however I saw a pdf file about the 75 IMSA racers. Mostly it was about the 2L turbo version, but there was also a mention of a version with 3L 12V. That engine was a highly tuned race engine for max power. The power in this engine was 300HP. So the Alfa guys in Italy actually got some real power out of this engine which has been an engima tuningwise for many people!

And yes here the IMSA 3L 12V: 300 Hp/8500 rpm, Would be a goood figure for the 3L 24V also! :)

http://www.scuderiadelportello.org/schede/SchedaALFA75.pdf
 

·
Registered
Joined
·
1,409 Posts
Given you're starting from an early Alfetta GT and not a GTV6 there will be quite a few things you'd need to look at, beyond just the obvious. For example the wiring looms are quite different as are the front panels and of course the hood. All necessary changes or adaptations for a V6 installatipn.

That's why many people down under slot in a twin-spark. Understand they're not as common in the US but globally parts are very easy to get and shipping parts around the place is hardly rocket science.

If the V6 option appeals, personally having owned and/or driven everything from 1.6 Alfetta sedans to highly modified 24V GTV6's on both the road and track (and including 12V 3.0 V6's) I'd not bother with a 12V if a 24V is available. Aside from the power figures you need to feel the difference. It's chalk and cheese.
 

·
Registered
Joined
·
606 Posts
Discussion Starter #19
Allister,

Good point about the wiring harness and other standard connections.

Thanks for everyones imput, anyone got pictures of some of these conversions they can post?

Thanks,

ncng

Given you're starting from an early Alfetta GT and not a GTV6 there will be quite a few things you'd need to look at, beyond just the obvious. For example the wiring looms are quite different as are the front panels and of course the hood. All necessary changes or adaptations for a V6 installatipn.

That's why many people down under slot in a twin-spark. Understand they're not as common in the US but globally parts are very easy to get and shipping parts around the place is hardly rocket science.

If the V6 option appeals, personally having owned and/or driven everything from 1.6 Alfetta sedans to highly modified 24V GTV6's on both the road and track (and including 12V 3.0 V6's) I'd not bother with a 12V if a 24V is available. Aside from the power figures you need to feel the difference. It's chalk and cheese.
 

·
Registered
Joined
·
606 Posts
Discussion Starter #20
Jes,

I really would like to get aleast into the 210-220 hp range and easy and reliable as possible.

And maintain a very OEM look to the car.

ncng


IMO the increase from a 2.0 Nord to a 2.0 Nord TS is not a lot - maybe 20 HP on paper. Driveability may be better, but if you go through the trouble of an engine swab I would personally aim higher, at least 3.0 V6 - either out of a Milano, 164S (Motronic, higher compression), or 24v out of 164 LS or Q. A junk-yard late style Milano 2.5 V6 will probably give you the parts needed to convert a 164S engine. I put a 164S engine in my Milano race car - the conversion is documented in the Roxanne thread.
Jes
 
1 - 20 of 63 Posts
Top