Wayne's New Engine - Comments Anyone?

[Wayne 962]

Okay, I think I've got it covered. Here is the engine I'm going to be building for my 914-6 conversion:

- 3.0 Turbo Case
- 2.7 crank and rods
- 3.2 pistons and cylinders
- 'S' cams
- 3.0L Turbo Heads
- 40 Webers
- 2.7 Distributor
- Headers + Sport Muffler

Explaination? The 3.0L Turbo case has the smaller flywheel end, so it can accept the 2.7 crank and rods. This crank can be used without hassle with the 901, which I am running in my 914. John Williamson (Otto) has run the 901 with his 2.9 engine successfully in the past (I think that was dynoed at over 300HP).

The 2.7 crank and rods are the same as the 3.0 crank and rods except for the flywheel end. I have these handy.

The 3.2 Pistons and cylinders are a Mahle 3.2 "RSR" set that I recently became aware of. It's a high-dome 10.5:1 compression set with Nikasil cylinders. I will shim the cylinders so that I can run it with single plug and pump gas. I could go with an Electromotive HPX twin-plug system, but that seems a bit overkill for me right now (would also add about $2K to the total price, and doesn't seem like a good investment). Also, my tech editor for the book (Tom Woodford) thinks that there might be some twin-plug clearance problems with the trailing arms on a 914-6 (I'm not sure how the GTs did it...)

'S' cams - good all-around agreesive profile camshaft. Should give plenty of low-end power and torque when combined with the 3.2 displacement. I could go with something even more aggressive, but I don't want to sacrifice my low-end torque.

3.0L Turbo heads - these have good port sizes (32/36). I have those twin-plug 933 heads (which will be for sale soon) but I think that the port sizes on those (40+) will be a bit too large to use on this engine (which will be a street motor). These heads should be a a good all-around size for use with this short-stroke 3.2.

40 Webers. For a street motor they should be fine. If it were a high-revving race motor, it might be starved for air. However, I have these, they are rebuilt, and ready to go. The 3.2 is right on the border where you might need the larger 46s, but the 40s should work well if they are jetted properly.

2.7 Distributor. Good, all-around curve for an engine like this. Tom Woodford has built many engines using this particular curve with very good results. Just need to lock the vacuum retard plate inside the distributor.

Headers + Sport muffler. Not sure what size pipes (I'm don't even remember which size I have), but the Sport muffler should be a good addition.

Should be good for about 240-260 HP...

Comments? Questions?

-Wayne

[jabb]

hmmmm Turbo Case Turbo heads..... Dump the webers and the "S" cams... get the CIS and find that Turbo to complete the package

[Fishcop]

There's a pretty good book out called "How to Rebuild Porsche 911 Engines" by some bloke called Dempsey. Maybe that could be handy?

[ein 6er]

yeah, i have a comment .......... HOLLY MOLLY!!!!! can you say "Frankenmotor"?!?

sorry, i don't have the technical knowledge to comment on the engine build, but with 240-260 hp, you will be very pleased i'm sure.

i've never heard of any problems with the twin plugs and the swing arms, the GTs had them and i've seen others. with the turbo vavle covers don't forget to machine the fins down as per the PP tech article. (-:

please keep the 914 board posted with any details on the progress of your conversion!!

regards,

doug waters

[CamB]

I've pretty much got that lot, except:

- sc case and crank
- mfi throttle bodies (bored to 40mm), converted to EFI
- std early 911 exhaust
- I DO have twin plug (964 dizzy).

I have 245hp at the wheels (270hp at flywheel). The EFI (surely) helps, as does the twinplug. Should be fun! Make sure you run some sort of CDI, of course.

[Wayne 962]

I'm going to run the stock CD system that came with the 2.7.

I've heard from other people that turbo-charging the 914 is just not a good way to go. For a variety of reasons, it makes the car virtually undriveable.

-Wayne

[rcwaldo]

Wayne, I know of a good place to get rebuild parts...PM me and I'll tell ya..

Chris

[RoninLB]

Originally posted by Wayne at Pelican Parts

- 3.0L Turbo Heads- 40 Webers- 2.7 Distributor

- "Should give plenty of low-end power and torque when combined with the 3.2 displacement. but I don't want to sacrifice my low-end torque."
--- maybe an MSD will keep your spark plugs cleaned with carbs?


"3.0L Turbo heads -These heads should be a a good all-around size for use with this short-stroke 3.2."
--- maybe smaller ports wll give more mid range velocity/torque?

"40 Webers. For a street motor they should be fine. the 40s should work well if they are jetted properly."
--- yep.. 40s should keep the velocity up, and plugs staying cleaner.

"2.7 Distributor. Tom Woodford has built many engines using this particular curve with very good results."
--- wouldn't a quicker low rpm advance work better with carbs, than a CIS dizzy?

"Should be good for about 240-260 HP..."
--- party hearty

Comments? Questions?

-Wayne
-Ron

[Wayne 962]

Supposedly the 1974 2.7 distributor I have is a very good curve for this purpose. I'll have to defer to my experts on this one, as I am not super-familiar with the various profiles used on the early cars.

I think that smaller ports might be restrictive. I really don't want to go with the 40mm ones that the airplane (933) heads have...

-Wayne

[CamB]

It is basically a great big S engine (or a big RS engine) - why wouldn't you use the RS curve? Or the 3.0RS (which had more compression). Now there is an idea...

Cam (I'm bench racing here, its not like I actually know much about anything!)

[911pcars]

Wayne,
I think the early S/RS heads have 36mm intake ports. On a 2.7, I don't think they're too big or sacrifice a lot of low-end torque. With the larger displacement 3.2, 36mm intake ports should be fine. Long stroke and 9.5:1 compression helps alot in the torque department. Moving 2000 lbs will be quite easy with this engine. Are there any other advantages using 930 heads? How about drilling the twin plug holes now for future ign./compression upgrading? Remove the cylinder spacers, install twin plug system and get another relatively low-cost shot of torque and power (if needed).

Question: What is the drawback in using a twin MSD (or equivalent) system to ignite twin plugs? A single pointless distributor should be able to do this, albeit with less control than an ECU-controlled system. MSD, Crane and others also make user-controlled ignition boxes that could work in this application.

I believe GPR (parts house) has a 3.2 914-6 they've been running for promo purposes. Do I see a parts house shootout in the not-too-distant future?

Sherwood

[Wayne 962]

The 2.7 distributor is what I have in hand right now, and the curve should be very good for this application. I could probably tweak the curve and get a bit better HP (it would probably be just guesswork), but that would be a lot of work for a little gain.

Sherwood, There is no point in installing the 2nd plug sets now. You can't just install a 2nd set of plugs and igntion and get HP gains. The true usefulness of twin-plugging comes from being able to run increased compression. So, if I went with the twin-plug, I would tear the engine down to increase the compression ratio. At that time, I would drill the heads. See page 103 in the engine book for details...

I have a line on a complete set of 930 heads that are done and ready to go (with the Walt stamp of approval to accompany them). It's what's available to me right now - opportunity.

You can certainly run two MSD boxes - nothing against that. The alternative would be to run dual CD-boxes. You need to distribute the spark to each cylinder though, and this is what costs big bucks. See the book for more details.

Dave (GPR) let me drive his car last time I was up there. It's fast - very fast, but it's a stock Motronic motor, from what I can tell, so it would be good for about 200-210 HP, maybe more because the 914-6 headers are less restrictive. That certainly would be an interesting shootout - hadn't thought of that before. Cool!

-Wayne

[911pcars]

Yes, distributing the 2nd set of sparks is the expensive part. I overlooked that.

Sherwood