3.6 EFI slide valve build

[Nux]

This winter I'll be building a 3.6 for a friend.

Its going into a 1974 RSR replica and he would like it to resemble the RSR engine - but with updated hardware. It's mainly a fast street car. Car is build from bare chassis and up.

So, now the fun begins!

A 1992 3.6 has been bought. We're currently using stock crank and pistons as well as stock heads.

William Knight mild-isch street cams and headers. Dynomax 17321 muffler. So far so good.

The special touch with this thing is going to be induction: Slide valve with EFI. I was going to use Jenvey or similar, but he insists on the slide valve look, with the tall red velocity stacks. It does look the business.

I guess we're backdating the engine. Max HP is not important (for now), and I think 300hp is within reach with this setup, which is enough for a very light street car.

I've done some research, and it shouldn't really be that difficult.....I hope.

Old school Twin Plug dizzy has been purchased from a fellow pelican. Slide valves will probably come from EB Motorsports. EFI injector blocks adaptors from Retro-Sport. ECU will be Megasquirt. A few hoses and cables - and some cash - and thats it!?

I'm not sure how to tap a MAP signal and/or vacuum for the brake booster. TPS as well of course. I'll talk to EB about that.

Do I forget something? Suggestions?

Pic of the inspiration from Patrick Motorsport:

[Jonny042]

Ditch the booster..... solves at least one problem and saves a a few pounds (and get rid of the Goldbergesque assortment of pushrods and belcranks in front.

[Dmitry at Pelican Parts]

Keep us updated on the build progress and post lots of photos - this thing sounds like it'll be quite the little street rocket!

[Nux]

Well, as some of you may already know, we are in the process of making new Elliptical Roller Barrel ITB's.

So the slide concept has been updated to a roller concept.

First fitting today:

[MoreGAS]

What do they weigh (these barrel valve bits) as they seem pretty substantial?

[Peter M]

Simply "wow"

Good work Nux!

[safe]

Originally Posted by Nux

Well, as some of you may already know, we are in the process of making new Elliptical Roller Barrel ITB's.

So the slide concept has been updated to a roller concept.

Any reason to reinvent the wheel? JPMotorsport in Helsingborg, not far from you, makes barrel ITBs.

[r lane]

Oh we like inventing the wheel, big part of the fun. It can definitely not be the prudent way to go, but away we go anyway. Bought this setup from Mittlemotor.

[Nux]

Originally Posted by safe

Any reason to reinvent the wheel? JPMotorsport in Helsingborg, not far from you, makes barrel ITBs.

Yes they do - just not for Porsche 911's (to my knowlegde)

They make some pretty wicked VW engines by the way. And Volvo's and Fords.

Titan also makes roller barrel ITBs for Caterham.

And it all started out as F1 tech years ago.

So, we're not reinventing anything - just adapting a well known fantastic concept to our Porsches

[safe]

Originally Posted by Nux

Yes they do - just not for Porsche 911's (to my knowlegde)

They make some pretty wicked VW engines by the way. And Volvo's and Fords.

Titan also makes roller barrel ITBs for Caterham.

And it all started out as F1 tech years ago.

So, we're not reinventing anything - just adapting a well known fantastic concept to our Porsches

I thought they made them custom, It was years since I talked to him.

Yes, really cool engines, he makes 356 and 911 engines too, this is supposed to make 230ish hp. It has his own custom heads. Going into a 356.

[Nux]

Originally Posted by MoreGAS

What do they weigh (these barrel valve bits) as they seem pretty substantial?

Each bank weighs 2.6kg for the big bore setup, which is 400g more than the small bore (two stud) Triumph setup I have on the shelf.

[Nux]

So, finally I'm ready to get this engine going. Very excited.

[al lkosmal]

Beautiful work. i can't wait to see the results.

regards.,
al

[Jeff Alton]

Nice looking product. Interested to hear how they perform in terms of outright HP and driveability. I would not worry about the weight of them....

[Nux]

Originally Posted by Jeff Alton

Nice looking product. Interested to hear how they perform in terms of outright HP and driveability. I would not worry about the weight of them....

Well two months ago we did a direct test on a 3.0 engine. We currently have two sizes:

A "small" bore for the two stud engines and a "big bore" for the three stud engines

We can change the size of the port entry - but not the throttle size. For example, the small bore set comes with 42.7mm throttle and a choice of 39 or 42mm intake port.

The big bore set has bigger throttle size and a choice of 42 or 45mm intake port.

They flow tremendously well. The small bore set flows equivalent to 51mm conventional butterfly throttles. This is of course very very good BUT if your engine is not either a big bore (3.2++ for the two stud set) or 3.8 (for the three stud set) OR heavily tuned for high rpm - these sizes will be too big.

So, to make a long story short: Our 3.0L engine has 10.5CR, twin plug, DC24/21 cams (not good for this application) SSI's and Dansk Two out. Megasquirt EFI, but old school twin plug dizzy.

with conventional 43mm throttles power was 243hp at 6100rpm.

with JSR roller barrel throttles, power was 253hp at 7100 (!!!) rpm.

Same dyno, same operator, same engine configuration and same temperature. We ONLY changed the throttles.

however - we lost torque. Power is super smooth and torque curve is flat as a pancake. They sound amazing! And feels amazing too. But they are simply too big for this little engine. Maybe a cam change to something hotter would be nice. I'll talk to William Knight about that