Sugestions for a Fast Street 2.0L enigine

[danyl]

I did a search of the board on this topic and it is well covered, but the information is scattered. I was hoping I could get a consolidated thread on the topic.

I had a thread: Euro vs. Spica manifold, and it developed into an exciting discussion on modification of a 2.0L for fast street. I'd like to continue it here.

I have a working engine from an '86 Spider with 60K on it. I'm willing to spend the money, but before I do, I want to undertake exhaustive research, so that I don't decide later that I wish I had done something differently.

I want to do most of the work myself, therefore the mods need to be inline with something a reasonable mechanic with a decent set of tools can accomplish. I hope that this will also appeal to others assuming that most people DON'T have easy access to a dyno and tuner, nor a high performance machine shop.

That's not saying I won't take the vehicle to a dyno, just that it shouldn't be absolutely necessary.

Msiert's Black Spider project is inspirational, but he has a number of professionals participating. I don't have such luxuries.

So far the suggestions have ranged significantly.

The basic suggestion is: Borgo 10.4:1 pistons and liners from IAP and a Centerline head with wide valves and their headers. Many good comments are posted on the board about this setup, but no one has mentioned if it can obtain 150hp or greater.

Other suggestions have been extremely modified heads: ported, shaved, and CC'd, with matching intake and exhaust manifolds. They would require aggressive cams.

Jim K's book is also a good way to go, but I would have to omit the porting portion since I'm not willing to take a dremel to it myself, and don't have anyone local who can ablige me.

I can also purchase aluminum pistons, but I'm still uncertain how far I would have to take everything else to take full advantage.

I'd like reccomendations on full recipes, i.e. pistons, heads, cams. Which combinations work well together?

The only portion of my plan that I am holding very strongly to, is that I want to use Weber 45DOCEs first. I have a considerable amount of experience with carbs, and I feel comfortable with them. After the engine is running well with the carbs, I will then begin a conversion to the Autronic EFI. I'll attach the carbs via a Euro manifold with rubber mounts to the Webers. This also gives me the option to get aftermarket ITBs for the EFI conversion. I like the SPICA manifold EFI conversions with the Haltech ECU found elsewhere on this board, but I can cross that bridge when I get there.

I already spent a pretty penny on a complete exhaust from Centerline with headers. I'd hate to end up not using it, but if someone has a compelling argument I'll listen. It would most likely not match up with a ported head.

Webcam's cams have also been suggested. Does anyone have an existing setup that incorporates them?

Alfaparticle has informed me about his complete setup and I like what I heard. Comments from others about their own setups are welcome.

[oldschooleuros]

Maybe I am missing something here, but you own a 87, which is fuel injected... Are you wanting to convert it to carbs???
Anyhow, ever consider forced induction? With the stock motor, a smaller turbocharger like a mitsubishi 13g, or a garret T25 would be excellent, and contrary to popular belief, it is not as expensive as everyone thinks. If you know how to weld, and have a basic forced induction knowledge base, you can do it for under 2500. I know, I have my flamesuit on lol... But it can be done. Webcams make great camshafts, and I know people that run them on Mitsu 2.0s with awesome results. If all motor is a must for you, I cannot throw too much input in, because I do not know too much about what Alfas can do. I know 10:4 comp is pretty good, but I think you can go higher with 91 octane, and add meth injection, 11:1 is certainally doable. There are lots of factory cars with 11:1, therefore I feel you could do it, but maybe I am wrong, so do not quote me.
A good intake manifold would always increase power on EFI cars. I am not sure if anyone has experimented with SMIMs on Alfas (Sheet Metal Intake Manifold) but on just about ANY 4 cylinder, they can increase power at extreme levels. I have seen Hondas and Mitsus pick up an honest 40 tire hp on a dyno.

[Gary Williams]

Whatever you do, pay attention to what is said elsewhere about the use of 10.4:1 Borgos vs. the 10:1 Motronics pistons. You can actually do better with the Motronics because you can run more distributor advance.

Also, I don't understand why you'd want to build a FI motor for carbs and then plan to switch to EFI later. Seems to me, if you want to save money you'll build your engine for one or the other from the start. That way you can tailor all the bits and pieces to work as a system: cylinder head, cams, intake, exhaust, ignition, etc.

I have Weber 45s and they work great, but my engine was built for them. You will be overcarbureted with 45s unless you design the cams, cylinder head, intake and exhaust to work with them. There's a simple software program here: Carb software . It will help you choose the carbs you need.

My cams are 11mm by Megacycle via AlfaPartsCatalog. The owner, Jon Norman, is a long-time Alfa racer, engine builder, all-around wizard. The head was given bigger intake valves, cleaned up and port matched by Rich Goodrich. Likewise, the intake manifold was port matched by Rich.

Headers are a pain and not worth the money unless you're going racing or, like me, want your engine bay to look pretty. And, no, my engine isn't just another pretty face, it's good for 160-170hp, depending on whether or not I'm wearing my fishing hat.

Is that enough to start an argument and/or discussion? Let the party begin!

[Greg Gordon]

Supercharger!

[oldschooleuros]

Quote:

Originally Posted by Greg Gordon Supercharger!

[RossoGTV4Me]

Gary:

Regarding:
"10.4:1 Borgos vs. the 10:1 Motronics pistons. You can actually do better with the Motronics because you can run more distributor advance".

Are the 10:1 motronics lighter as well?? Is running more distributer advance the main benefit with the motronic pistons?

I was thinking of using JE Pistons and overbore the liners to aim for 11:1 compression. I believe CA Super Unleaded 91 would still be ok..not 100% sure though.
I have a Sperry Stage V head, want to use 12mm intake cams with a lesser 11.1 AD Exhaust cam. 47mm intake valves/39mm exhaust valves(w/45*cut angeles), Shankle carb converson plates with ported SPICA manifold to match head porting. (The longer carb conversion plates add length to the intake which is benefical from what I understand). I plan to use curved GTA horns in a GTA airbox to keep some mid-range. I have 40 DCOE webers and not sure if jetted right will not be better then 45 DCOE's.

Thoughts...

Quote:

Originally Posted by Gary Williams Whatever you do, pay attention to what is said elsewhere about the use of 10.4:1 Borgos vs. the 10:1 Motronics pistons. You can actually do better with the Motronics because you can run more distributor advance. Also, I don't understand why you'd want to build a FI motor for carbs and then plan to switch to EFI later. Seems to me, if you want to save money you'll build your engine for one or the other from the start. That way you can tailor all the bits and pieces to work as a system: cylinder head, cams, intake, exhaust, ignition, etc. I have Weber 45s and they work great, but my engine was built for them. You will be overcarbureted with 45s unless you design the cams, cylinder head, intake and exhaust to work with them. There's a simple software program here: Carb software . It will help you choose the carbs you need. My cams are 11mm by Megacycle via AlfaPartsCatalog. The owner, Jon Norman, is a long-time Alfa racer, engine builder, all-around wizard. The head was given bigger intake valves, cleaned up and port matched by Rich Goodrich. Likewise, the intake manifold was port matched by Rich. Headers are a pain and not worth the money unless you're going racing or, like me, want your engine bay to look pretty. And, no, my engine isn't just another pretty face, it's good for 160-170hp, depending on whether or not I'm wearing my fishing hat. Is that enough to start an argument and/or discussion? Let the party begin!

[Alfar7]

Since Dan says he has a sound motor and this isn`t for racing, I still fail to get the need for spring for more pistons.
The stock 9.0:1 pistons can be the base for a much better 91 to 93 octane motor since it offers a friendlier combustion chamber shape than either the Motronics or 10.4 Borgo pistons. The JE`s are a waste in expense when measured against performance gain and flame travel issues. And there is the liner boring expense.
Proper head prep is the key to making these motors work. If you want compression, mill the head to get it. Spend the build $$$ on proper porting, seat shape, valve shape (no 3 angle stuff) and with good designed cams & intake you can make 160 to 170 with those simple ingredients.
To get to 11.0 to one will take about .070 cut from the head, but it will still run on premium because of the combustion chamber shape.
The stock Euro manifold will have to be ported for the 45mm rubber mounts and that has to be done correctly(all the way through). The motor side of the manifold should be closely matched to the head ports.
To make any power 45mm Webers are necessary, Up through 3rd gear not much will be noticed if comparing them, but in 4th & 5th above 4000 RPM the 40`s just wont have the pull.
I tried to send Dan pics but his email rejected them. The ones below are of the motor I built for the Spider. Based on a 39K mile `88 "Bosch" motor.
the heads are ported to 40/41 oval intake & 35 exhaust, cut .060 to get 10.6:1,m seats are taper cut with reshaped valves (std size Steel, no sodium), guides are bronze, about .450 shorter than stock(plenty of room for higher lift cams). Springs are Isky, retainters shortened & lightened. The manifold has 45mm rubbers and is ported from 45 to 40/41 to match head. The last pic is of the high ported head for the same block with 40/44mm -36mm ports for a EFI application using a shortened runner Bosch manifold adapted to 43mm "Spica" throttle bodies.
Dan, sorry the email didn`t work.

[Tifosi]

Roughly how much porting did you have to do before the factory injector clearance cuts went away on those intake ports?

[danyl]

Richard,

Yeah...My email provider has an attitude. Nice pics though. I'm liking your argument more and more for putting the work in the head and leaving the block in stock configuration.

Gary,

Yes, I routinely make things more complicated than necessary. My method in this case is simple however. I'm confident and experienced with carbs, I'm clueless with EFI. I want to LEARN about EFI by building a system myself. I want to build the system on an engine already running well. It's easier to troubleshoot when things go one step at a time.

Back to Richard,

Let's say I deviate from my plan of safety and familiarity, bite the bullet and go straight to a head that requires a new programmable EFI. How much would I be biting off at one time? I'm on my own here (sink or swim). With baby steps I could go to a new ignition and get that working first before adding the EFI. Even using the EFI from Autronic, which has ignition control, I could still use the RML ignition (easier to set up), get the EFI running and then later let the Autronic do everthing, instead of trying to juggle all these managment events at once.

Everyone,

Mostly what I was hoping this thread could be about is complete recipes for engines, not just comments about partial mods. Richard has provided one: it uses stock pistons with highly modified heads and high lift cams. It's enticing. Has anyone got a challenging rebuttal for a different complete setup?

Danyl

[Greg Gordon]

Oldschooleuros: I feel the need to point out a few things about your post.

1. Both superchargers and turbochargers use power from the engine to drive them. So do high compression pistons, stiff valve springs, high lift cams etc. In fact the whole engine takes power to make power. Piston engines usually use about half their horsepower just turning the motor. In other words an engine putting out 200 flywheel horsepower engine burns about 400 horsepower worth of fuel. This is expressed as BSFC and is usually around .45 for a N.A. motor and around .55 for a turbo or supercharged engine.

Modern superchargers are very efficient and take very little power to drive. Turbochargers rob power via exhaust back pressure, not via a belt, but they still rob power. Actual power losses between the two systems are very close at the levels of boost one would most likely use on a street Alfa.

2. Changing boost up or down with a supercharger is very easy. Worst case it's a pulley change. I actually had in car adjustable boost (only practical on a Roots, not a screw or centrifugal supercharger) on my GTV6 and could select from 7-10psi with a lever. Your statement that it's a "PITA" to change boost with a supercharger is really uniformed, or old school. This was true with the glimmer drives for GMC blowers 20 years ago.

3. The "locked into one size" argument is somewhat outdated. The modern units have a pretty wide efficiency range. For example a properly chosen supercharger can work well from 180hp up to about 300hp on a 2 liter engine.

4. Ultimately both turbos and superchargers have the same amount of power potential in a Spider because both are limited by the same thing, the transmission. Neither system have a solid performance advantage in this case. It really comes down to personal preference.

Greg Gordon,
hiperformancestore

[Greg Gordon]

Richard, that's some really nice looking work there! If I was to build a normally aspirated engine I would follow those guidelines.

I see you mention a dislike for the 3 angle valve jobs. Why is that? I normally go with a full radius cut set, although in my case, it's really not a big factor either way.

It's nice to see someone else saying good things about the stock pistons. In the V6 I found they held up perfectly with 10 pounds of boost, no intercooler and L-Jetronic. That's asking a lot for stock cast pistons. The factory used good stuff!

Your point about flame travel issues is a good one. That's often overlooked.

What EFI system are you using? I have two SDS EFI 4 cylinder projects going on right now. It's been very successful with the V6 and I have very high hopes for the 4cyls.

All in all, I don't plan to ever build another normally aspirated engine for myself so I am really looking at different issues.

Greg

[oldschooleuros]

Quote:

Originally Posted by Greg Gordon 3. The "locked into one size" argument is somewhat outdated. The modern units have a pretty wide efficiency range. For example a properly chosen supercharger can work well from 180hp up to about 300hp on a 2 liter engine. 4. Ultimately both turbos and superchargers have the same amount of power potential in a Spider because both are limited by the same thing, the transmission. Greg Gordon, hiperformancestore

[Subtle]

Got to follow the install of the BMW transmission.

Will add that the waste gate control on my Turbo Wagon has a high-low button, that can be set at different levels of boost.

With the vf 34 turbo, the lowest it can be set at is 13 lbs, and the high is set at 15.5. The high provides rather good acceleration, with acceptable load on the whirling parts.