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.

-Wayne

[kellzey]

Why are you asking us? Didn't you "write the book" on this topic? Ha ha!

How do the Turbo heads differ from the early SC heads? I don't know much about the turbo parts.

Are your carbs going to be big enough for that high revin' S-cam? Don't you wish they made 43mm triple Webers? It seems that these 3.0/3.2L engines always fall in that range using the carb sizing forumla

Sounds pretty good.

[mike mueller]

Sounds like fun

Ditch the Webers (don't even think of CIS) and move into the digital age with a nice Programmable Fuel Injection

[campbellcj]

I don't know enough to comment on the rest of your build spec...but FYI the Ottos "Rudy" car is now running a 3.8RSR twin-plugged Motec powerplant, with a 901 trans. The same trans has been in the car for a number of years now and the car sees 5-10+ track events a year, which it usually wins. I have ridden in the car and it pulls hard enough to pop your eyeballs out the back of your head...

I do wonder though, if you're after a strong street car, why not use a more "mainstream" 3.2 Motronic engine with a good exhaust and reprogrammed DME? Seems like it would be significantly less expensive/exotic and a friendlier torque curve for street use. The car would run clean and start on the first try in any weather conditions.

How many times would you really use/feel the extra 20hp or so on the top end that you gain from the larger ports and S cams? And why bother with high-compression p/c's if you're going to shim the compression back down and run single plus, with pump gas, anyway?

[Wayne 962]

The electronic fuel injection would cost about $5500 if you include the throttle boddies - too much for this particular engine.

As for a stock 3.2? It's much less expensive to do this engine than it would be to rebuild a stock 3.2. The 3.2 is also tough to get to work with the 914 901, and also not exactly easy to fit into the 914 engine bay. It would probably cost me about $3K for a good core 3.2L engine and about $6K in parts to rebuild it.

The advantage to this engine is that I can expand it later on, and it will be truly a unique beast.

-Wayne

[jamcleod]

can't wait to see the book.......

[Dave at Pelican Parts]

Interesting... Should be a fun drive.

From talking to people with large-displacement engines and "S" cams, the combination is actually not "peaky". Evidently the large displacement "calms down" the S cams, which are high-RPM-only on the small-bore motors.

I personally would still prefer the 3.2 Motronic engine.

--DD

[ss6]

Minor points, but what are the issues with 3.2 fit and 901 hookup? My 901 bolted right up to the 3.2 and it's stock flywheel with a clutch kit and starter gear adapter. No hacks were needed to get the engine into the 914, save the fins on the valve covers, but that's needed for any six transplant.

Sounds like a fun project, especially if your loose parts collection happens to include the stuff you mentioned. For 250 or so HP, how would a stock, low miles 3.6 transplant compare to your project if you had to pay yourself for your labor?

[scg]

Sweet!

...so... what are you going to do with the 2.7 that was rebuilt for your book >heh heh heh
(that was it, wasn't it)???

[airsix]

Originally posted by Wayne at Pelican Parts
The electronic fuel injection would cost about $5500 if you include the throttle boddies - too much for this particular engine.
(snip)
-Wayne

Wayne, Wayne, Wayne...

Used 3.2 intake w/ TB & fuel rails: $300-$350
EFI Pres. Regulator: $free
Used fuel pump: $70
Megasquirt PEFI: $150

That's $570.

Sell your carbs and it's a net profit. If you don't like the Megasquirt idea (not expensive enought for your taste) go with an SDS or Autronic. You'll still come out about even when you sell the carbs.

-Ben M.

ps - I did PEFI on my 1.7 for ~$500 ($650 if you count digital ignition and turbo). Mueller did Megasquirt for I think around $250. No reason NOT to use EFI any more.

pps- I do confess that carbed sixes do sound better though.

[confused]

There isn't too much fitting problems with a late engine and a 901. I have a 3.0 and a Kenedy adaptor flywheel. THe flywheel is only $200 to fit a 9 bolt crank and the KEP flywheel was top quality. Although if you use the non-flanged 6 bolt flywheel then you can just use a new fatory 914-6 flywheel for $300.

Here is a question, why not use 78-79 SC heads, they have a intake port of 38mm (I think) where as 80-83 has 36mm. Carbs like big ports.



and how the hell do I change my username on this board

[siverson]

Twin plug heads fit fine on the 3.6 liter engines in a 914, and I believe it is even wider than the 3.0/3.2 engines.

But, you do have to drop the engine about 3 inches so that you can remove the bottom valve cover to change spark plugs (it hits the inner suspension console "ear"). Maybe that's what you meant by clearance problems...

http://www.pelicanparts.com/motorcity/siverson/914/36/36in-nosheetmetal.jpg

-Steve

[Dave at Pelican Parts]

Originally posted by confused
...and how the hell do I change my username on this board

Click the "PM" button in one of Wayne's posts, and ask him nicely to change it for you.

--DD

[Wayne 962]

I forgot to mention that the turbo heads are ported and twin-plugged. You can't use 'S' cams with the Motronic fuel injection setup - there's too much fuel reversion. You have to use throttle bodies (TWM) or so in order to get an aftermarket engine management system to work. I've got someone trying to get me an 'eval' unit of the TEC-3 for an upcoming article. I'd still have to shell out big bucks for the throttle boddies though - those are *not* cheap...

-Wayne

[airsix]

Originally posted by Wayne at Pelican Parts
You can't use 'S' cams with the Motronic fuel injection setup - there's too much fuel reversion. You have to use throttle bodies (TWM) or so in order to get an aftermarket engine management system to work. I've got someone trying to get me an 'eval' unit of the TEC-3 for an upcoming article. I'd still have to shell out big bucks for the throttle boddies though - those are *not* cheap...

-Wayne

Wayne, you don't need to run individual TB's. You can, but you don't have to. There are several ways around this.

1) Program your PEFI to just meter fuel based on throttle possition, rpm, and temp - ignoring MAP (Think MFI). Sounds crazy but it works. I've done it (just for fun to see how well the car would run. It ran great)
2) Some ECU's will allow you to ignore the MAP signal at low rpm. This allows you to run a cam with big overlap and still make it run nice. Above a set rpm you program in MAP as an input because high-overlap cams are only a reversion problem at low rpm.
3) Some people have built a chamber with restricted orofice in the vacuum line to add volume and dampen the vacuum pulses caused by wild cams. I don't have any experience with this, but it sounds plausable.

Just some thoughts.

-Ben M.