3.0 > 3.2 - Some questions.

[Dizzy]

I have just secured a 1982 3.0 engine for my project car. I’d like a little more horse power than stock and would like to get there without spending better than 10K to do it.

Based on this, I have some questions. However I find it important to point out a few items. Firstly, that this is project is being built for the street, and secondly, being located in north eastern Ontario Canada I have only access to 91 RON for fuel. This will also be run with 40mm webers.

1) I wish to increase the displacement of the engine, i.e. Mahle Motorsports piston and cylinder set - 3.0 > 3.2. However these are available in 10.1 and 10.2:1 compression ratio. Can one go to 10.2:1 without going dual plug? I don’t wish to go dual plug. In my mind 3.2 P&C set @ 9.8:1 would be perfect, but it seems this logical combination is not available. Comments and suggestions would be appreciated.

2) anyone care to suggest a cam? I was thinking of Web Cam’s 120/104 for this build.

So in a nutshell its time to make a plan. The goal is to get to 250 - 275 HP by increasing the compression ratio a wee bit, adding some displacement and a fairly aggressive cam for the street.

I look forward to your advice and wisdom.

Cheers

Mike

[Dizzy]

Bump

[jpnovak]

IMHO I think you should run twin plug for the 98mm Pistons required to convert your 3.0 to 3.2. The issue is not so much compression ratio but burn rate and flame front travel across a large area. There is just not enough time for efficient, complete combustion. The other issue are those cams. I suspect that you will not get all the power out of them due to the relatively narrow lobe spacing and high overlap. This will push your powerband well beyond 7K. You will need to do a bit more work to get the engine to have longevity at that rpm. Also, I think weber 40s would be too small for those high rpms. You might want to look at a stock S or Mod_S/DC40 cam. Since you are building mostly for street I think an early E grind would be perfect. This will give you a healthy amount of torque starting about 2300 rpms and will pull hard all the way to 6800. That is fast enough for a 3.2SS.

What is the application? weight, transmission, etc. Gearing can play just as an important role as the displacement. Proper gearing will maximize the power output range of the motor.

[Dizzy]

Jamie,

Thanks for your reply. It made me go away and re think this project.

So i've come up with a few changes.

I have found a P&C set, 98mm with 9.5:1 JE pistons. However, Im still in the dark on selecting a Cam.

I did some reseach on the Cams you suggested. I used andersons book. However someone mentioned that his cam list in his most current edition, might not be correct.

However, I think the "E" is pretty close to the SC cam already, so i've ruled that out. I really want to make some horsepower without sacrificing in town drivability.

I considered the "s" cam, and Ive had a host of folks tell me I will have to live at 4K and above. If this is true, that would be too much. However I did have one guy tell me that the S cam in the 3.2 would be just fine as the large displacement of the motor would add some natural bottom end.

I started to look at "L" Cams or the Solex cam. This might be my choice. I cant decide - L cam or S cam. Grape and Cherry? Gees, there is a lack of information on this. Maybe some folks could chip in with there experinces with these cams above 3.0 litres.

I have decided to go twin plug. Im gonna go with the crank fired system from clewwtt. I have a friend at Response Engineering up here that will twin plug my heads at a reasonable cost. I like him, he's fussy and does nice work. Beside Soon I wish to dump the webers and go with clewett's injection system. This is untimately were I wish to end up in fuel management.

Thanks again Jamie!

Any info anyone else could provide would be great!

cheers

[sjf911]

My 3.2ss rebuild (9.5:1 JE) with 964 cams did 230 RWHP on the first rough dyno run which should equate to roughly 270 at the flywheel. However, this is with a common plenum EFI and twin-plugged, electronic ignition.

[RWebb]

SC cams - and all CIS cams - have almost no overlap -- the E does differ

[Dizzy]

Originally Posted by sjf911

My 3.2ss rebuild (9.5:1 JE) with 964 cams did 230 RWHP on the first rough dyno run which should equate to roughly 270 at the flywheel. However, this is with a common plenum EFI and twin-plugged, electronic ignition.

Thanks for the info. What did you use a 3.2 factory manifold? EFI was that the TEC3 system?

Cheers

[Dizzy]

Originally Posted by RWebb

SC cams - and all CIS cams - have almost no overlap -- the E does differ

Yes, it does differ, but my info suggests not very much. Correct?

Cheers

[Dizzy]

Originally Posted by sjf911

My 3.2ss rebuild (9.5:1 JE) with 964 cams did 230 RWHP on the first rough dyno run which should equate to roughly 270 at the flywheel. However, this is with a common plenum EFI and twin-plugged, electronic ignition.

If you had of choosen throttle bodies for this build, would you still select the 964 cam or something more agressive?


I suppose i should mention the induction system will be webers to start off with, but eventually migrated to TEC3 EFI.


Thanks

Cheers

[Eagledriver]

E cams are very similar to Solex cams. They are completely different than any CIS cams, so no they are not similar. Even T cams are much more aggressive than CIS cams.

-Andy

[sjf911]

Originally Posted by Dizzy

If you had of choosen throttle bodies for this build, would you still select the 964 cam or something more agressive?


I suppose i should mention the induction system will be webers to start off with, but eventually migrated to TEC3 EFI.


Thanks

Cheers

I used a carrera intake and throttle body to simplify the build out and lower cost. If I was going to use a more aggressive cam, I would have definitely gone ITB's.
I am using Megasquirt II EFI interfaced with twin Ford EDIS controllers for the ignition (1995 Aerostar parts from the junk yard).