Bill's 2.8 -4 Twin Plug Thread, 48x38 twin plug conversion Options

[Bills914-4]

Here's a few pic's of my planned conversion to twin plug with a Pauter cam (IMG:style_emoticons/default/smile.gif) , &
either MSII or MegaJolt with edis4 x 2 for ignition, Bill D.

[EdwardBlume]

You rock. (IMG:style_emoticons/default/aktion035.gif)

[Kirmizi]

(IMG:style_emoticons/default/popcorn[1].gif)

[kid914]

(IMG:style_emoticons/default/piratenanner.gif)

[Maltese Falcon]

Nice machining , twin plugs rock !
More pictures as availble please.
Marty

[0396]

Wow, congrats!

[r_towle]

Any flow bench work done on the heads?
How did the numbers look?

[Woody]

This is what I'm talking about. (IMG:style_emoticons/default/aktion035.gif) what compression are you shooting for? (IMG:style_emoticons/default/popcorn[1].gif)

[barefoot]

Here's a few pic's of my planned conversion to twin plug with a Pauter cam

If I read your calipers correctly you have a very large step increase in port size from outlet of intake manifolds to head port inlets, not a good aero flow path.
Whats the thinking here ???

[Bills914-4]

Thank you for the compliments & kudos ,

Rich , I don't have any flow numbers , I ported these heads myself (budget build)
I had Jorge at EMW do the twin plugs for me , I did the chamber work & cut the .060
step in the cylinder seating area ( trying to get a better seal , 103mm bore ) I had
Len ( HAM ) cut the valve seats on his Serdi machine ,

Woody , the compression will about 11 to 1 with a .032 deck machined into the head chamber area ,

Barefoot , that's a picture of the intake manifold before porting & after porting , 33mm before & 40mm after , & 50mm where the 48mm throttle bodies bolt on ,

Thanks again guys Bill D.

few more pic's

[Jake Raby]

Twin plug engines LOVE cylinder pressure! I always back up a few degrees on duration and start at 11:1 CR with the tightest deck possible. So far thats been good for 274HP from 2.8 liters on 91 octane. That engine had .025" deck.

You'll find that timing the engine is very, very far removed from your previous attempts and that it will optimize much leaner than it used to.

[Bills914-4]

Twin plug engines LOVE cylinder pressure! I always back up a few degrees on duration and start at 11:1 CR with the tightest deck possible. So far thats been good for 274HP from 2.8 liters on 91 octane. That engine had .025" deck.

You'll find that timing the engine is very, very far removed from your previous attempts and that it will optimize much leaner than it used to.

Thanks Jake for chiming in , these are those vintage heads I picked up last year on your e-bay site (IMG:style_emoticons/default/smile.gif) , wow .025 deck is a little to close for me (IMG:style_emoticons/default/biggrin.gif) , the timing I've read & been told will be less ,they say as much as 6-8 degrees less , this twin plug stuff is all new to me
but its time for a change on this motor ( 3yrs + running on this version) , I'd be happy with 200hp at wheels , 15 more than I have now (IMG:style_emoticons/default/biggrin.gif) , thanks Bill D.

[Bills914-4]

I'm hoping this cam will be ok , it was ground way before I decided to try twin plugs Bill D.

[gothspeed]

AWESOME!!!! (IMG:style_emoticons/default/smilie_pokal.gif)

What EDIS modules are those? Part numbers?

[Jake Raby]

The cam is a little long for what I'd choose, but there's more than one way to skin a cat.

Start timing around 22*BTDC full advance to be safe, at 11:1 it shouldn't optimize at more than 24*, if it does, well, then you'll have conclusive evidence that the cam was too long :-)

Glad to see the old heads getting some new life, those are several generations of vintage :-)

What you'll find with twin plugs isn't so much more WOT power on the dyno and bigger numbers, but mostly insane throttle response and unreal torque gains below 4K RPM, especially with the larger bore size that needs all the help with flame propagation that it can get.

[Bills914-4]

The cam is a little long for what I'd choose, but there's more than one way to skin a cat.

Start timing around 22*BTDC full advance to be safe, at 11:1 it shouldn't optimize at more than 24*, if it does, well, then you'll have conclusive evidence that the cam was too long :-)

Glad to see the old heads getting some new life, those are several generations of vintage :-)

What you'll find with twin plugs isn't so much more WOT power on the dyno and bigger numbers, but mostly insane throttle response and unreal torque gains below 4K RPM, especially with the larger bore size that needs all the help with flame propagation that it can get.

Cool , thank you very much , Bill D.

[gothspeed]

What valve spring arrangement will be used on these? ...... (IMG:style_emoticons/default/smile.gif)

Are any of these valves Ti?

[Bills914-4]

What valve spring arrangement will be used on these? ...... (IMG:style_emoticons/default/smile.gif)

Are any of these valves Ti?

The modules I picked up from the bone yard out of a couple of ford escorts , I'm leaning towards megajolt ignition with edis4 x 2 with Mario's crankfire gear & bracket for vr sensor (IMG:style_emoticons/default/smile.gif) ,
I'm already running EFI , CB performance quicktune (older version w/o ignition )

I'll be running CB performance's vw650 dual springs , I have a set in the heads I'm running right now with titanium retainers with .560 lift ,

stainless valves with Ti retainers (IMG:style_emoticons/default/smile.gif) ,
thanks Bill D.

[jimkelly]

http://thedubshop.net/

would dual plug be worth any extra HP on an otherwise stock engine?

does emw have a website?

carry on : )

[rick 918-S]

http://thedubshop.net/

would dual plug be worth any extra HP on an otherwise stock engine?

does emw have a website?

carry on : )

Jake posted in another twin plug thread that the twin plug worked best on large displacement engines. I would assume that would have to with the added volume of charge and the increased chamber area for the charge to expand. But I'm no expert.