Help me design a sweet engine
 

My car was hit a couple of weeks ago and it will spend "some" time in the body-shop getting fixed....

No better time to fiddle a little with the engine.

I am starting with a 1997 3.6 Varioram with Euro harness.
The sheet is blank and budget is somewhat flexible...
The engine will be used in a dual street/DE car.

I am thinking:
3.8 conversion
Ti valves and retainers
mechanical lifters
cams ??? no idea
rods ??? do I need to replace?
ITB Jenvey or TWM 3006
Injectors ???
EFI = Motec M600


I don't have any experience just a lot of reading on this board. I'd love for you guys to chime in and guide me.

I would love to get 310-315 usable rwhp with a broad torque curve but with the thrills of a screamer behind my back. Am I out of my mind?


thanks again

Hi Matteo:

Sorry to hear of your accident, but the fact that YOU are OK is the best news,......:)

One has a LOT more flexibility with regard for throttle response, drivability, and camshaft choice when you use a tall butterfly, 6-throttle intake system with EFI.

I'd suggest either a 3.6 or 3.8 with different cams (there are several good choices), Pauter rods, GT-3R oil pump, crossdrilled crank, solid lifters, our tall butterfly intake system and either DTA or MoTeC Engine Management. You'll need to make a decision about whether you want to use pump gasoline or not. It goes without saying that RS valves, better springs and Ti retainers are a prerequisite.

You can see our intake system on this page; http://www.rennsportsystems.com/1-c.html about halfway down the page. Thats a 330 HP 3.4 race motor in a relatively mild state of tune (race gas only) and a 3.8 would do much better.

Without question, your budget will determine what you do.

Nothing beats boost Matteo!!!

I was thinking (and again maybe I am talking rubbish here) to have a dual mapping set-up, one for street gas (93 oct) and one for race gas (100 oct).

Budget is flexible in the sense that I want to have things done properly. For example I'd rather spend a bit more for a proven EFI system but be sure than it works with no problems.

What is the displacement increase return? I mean a 3.8 is 5.5% increase vs a 3.6. Say that I could get 330 hp at the crank with the 3.6... Will the 3.8 yield 346hp? Or is there a diminishing return?

I am not set to have the most powerful n/a engine... I want it to be fun.

I hear you... I could spend the same amount of money, lower the compression ratio, get a twin turbo set up + IC, EFI and put out 750 HP...

Both kinds of engines have a totally different "feel" so the final choice depends on what you use the car for and what you like,...:)

I am set on a N/A engine right now... I'll leave FI for the next project

LOL,..The neck-snapping throttle response of a well designed 6-throttle intake (and proper Engine Management) has to be experienced to be appreciated, but it really makes an engine fun to drive, especially with close-ratio gears.

I like Steve's suggestions a lot.

if you are going to the expense of all the other stuff to make it rev happy, rods are a given.

The nice thing about displacement is that it is advantageous through out the whole rev range.

The downside of displacement is cost ~$4k last I looked.

I need to do my trans first, then maybe another 3.8 or 4.0 along the lines you are thinking.