Here's my plan:
Six conversion using rebuild (late) 2.7 with JE 9.5:1 pistons, tall cams, and PEFI for induction.

Here's what I've got: (all this for about $1,200 including the running PEFI on the -4 )
PEFI/ignition (already running on my -4)
late 7R-case 2.7 with 2 pulled studs. JP is hooking me up with his machinist in Portland.
914-6 flywheel
914-6 engine tin
KEP stageII clutch plate
headers & muffler

What I think I need:
Have engine machine work done this summer
Rebuild the engine this fall/winter
oil tank & lines
oil cooler & lines
front engine mount & hardware
clutch plate
intake (several decisions to be made here)
911 tachometer
oil temp guage
11-blade fan
alternator mount/fan-ring (missing when engine picked up - might turn up)

Am I missing anything big?

Intake - the big question. I've got the PEFI/ignition, but need to decide whether to use a 3.2 style plenum/runner intake manifold or build something with six throttlebodies. We all know which would be easier, but... GSXR 1000 throttlebodies have just the right bore size. Get two sets, lop the fourth TB off the end, and (ta-da!) - triple-throat throttlebodies with TPS, linkage, and injector bungs. Hmmmm..... Ok, back to reality. Will a 3.2 intake manifold bolt up to a 2.7 or did the spacings change?

-Ben M.

Two more questions (for now):

1) How high can you take the compression on a twin-plug six and still run 91 octane pump gas?

2) What do shops charge to twin-plug a full set of heads?


I ask because I have an aquaintence who twin-plugged his formerly race-gas-only 2.7 and now drives it on pump gas.

-Ben

I'll get back to this as time permits.

Use the 3.2 upper. The triple throat looks cool.. but you have NO way of map sensing or cold start valve control without making a common box sensing vaccuum from all the ports.. This sucks. I want my race cars to cold start and warm themselves up. I have to treat my tube car like a carbed car... holding the throttle open.

Do you understand what I'm trying to say ?? LOL

Used 3.2 uppers sell for about 300$ with fuel rails and injectors.

B

Ben; I have a 2.7 twin plug with 11.5:1 Mahle pistons. I usually add octane booster to the fillups. A couple of times that I had no booster with me there was no noticable difference in how the car ran on the street. I don't know about shortening the engine life by not running the higher octane though.

I don't think cold starts would be a problem. My ECU has temp-sensing cold start enrichment and can also do idle speed control via butterfly servo.

But...$300 bucks for a 3.2 intake with injectors and fuel rails? COUNT ME IN! I'd easily have that much into motorbike TB's, injectors, rails, plus all the stuff I'm forgetting. Plus months of fabbing up manifolds and linkage crap. Sounds like the 3.2 intake is the wise choice. Even if it won't sound as cool and will probably give up a few hp.

-Ben

Dan Hall's

503 289 5015

& before you get all giddy about the 3.2 intake:
your intake ports are 35mm, the 3.2s are 40mm.
Whatcha' gonna' do for cams?

Ok, I'll wait for Brad's comments on the 5mm port discrepancy, but I figured there would be some intake port work to do to make this work (didn't expect them to match).

What am I going to do about cams? Ask dumb questions of course.

My type-iv rarerly sees the low side of 3k, so as long as it screams from 3k or better I should be happy. I'd like to point my camera at my tach for a few autocross events to see where I really spend my time. (perception vs. reality)

Anybody got a chart that shows the torque curves or "on the cam" rpm ranges for the various popular grinds?

-Ben M.

Correct

"I don't think cold starts would be a problem. My ECU has temp-sensing cold start enrichment and can also do idle speed control via butterfly servo."

My TECIII does it also, but you cant run it with the triple throats without having a common small plenum with lines running to it from each port (with the IAC and a MAP.. and a AAR) I promise you will want IAC and AAR (even on a race car)

We are flowing air not fuel... the 3.2 upper should be fine even if it is 3-4mm off depending on what size ports you go with. I just hope it will bolt onto the heads.

This one needs to be converted to Excel.. but all the numbers are in place.

http://www.elgincams.com/c-por2.html

B

I misinterpreted what you said. I thought this was a known compatability. I hope it will work because it would be the easiest/cleanest way to do it. I'll see what I can find out. (Ben looks around for a 3.2 but doesn't see one )

-Ben M.

I have a few 3.2 uppers here, but dont have any 2.7 heads.

Wait.. I do have a few 2.0 6 heads around.

Be back.

B

SUPERTEC Head Studs

Anybody ever heard of these before? There's a set on ebay claimed to be wonderful, bla bla bla. Cheaper than Raceware by a few bills. Junk or something good? I've never heard of them.

SUPERTEC Head Stud Kit $525

You'll probably space the end of the auction and lose out anyway.

Guess not. "Buy It Now" only. This should be an easy one.

I used 24 ea full thread, black coated Divilars.....the latest iteration from Porsche.

Raceware Studs were considered, but.....with a 2.7L
pulling studs is a problem. Divilar studs have been known to break....so you get to pick your poison.
If you pull a case saver, the case is toast. Given a choice, I'll take a broken stud every time.

As I see it, these are the ONLY choices for studs....unless you're spending someone else's money.

No problems yet cause I have done everything I can think of to keep the motor cool....including an external oil cooler that is *required* for hp above 170 or so....ain't that right, Brad (with your 120 deg temps...was that F or C?)

I am in the process of configuring my 914 to a six. (Not happy with the V-8 handling). I am planning on building a 2.7 engine into a RS configuration along with the necessary external oil coolers and thermo bypass valve. Two areas I am concerned with are the studs and the fuel.

Initially, I will run either a 2.0 or 2.7 from which I will decide the exact direction I go with the engine. Downline I would like to use the CIS barrels along with the RS pistons which means I will probably have to change the CIS to MFI . What are your thoughts on this?

The engine will be built to the RS specifications which now leads to the other problem, one of stud longevity. I like things to last including cases. I probably can live with pulled or broken studs as long as the repairs can be made to extend the case life. The ultimate question is what to use: raceware, timecerts, etc. What are your comments and ideas on this item? It is my buck I am spending not someonelses therefore the expenses are not a concern at this time.

Appreciate any comments concerning these matters. Thanks.

Steve Hurt
Shoguneagle

ie. Downline will probably run the early S cam.

First, buy Bruce Anderson's book. There is more info in there than you can shake a stick at. There are a few things that are in there that folks seem to skip over, however. Your mention af "CIS barrels" ( I assume by that you mean cylinders) brings up one of those.

*Most* 90mm CIS cyls are Alusil. These require ferocoated pistons....which are only (AFIK) available with the CIS dome. These are made by KS. Put any thing else in them can (or will) cause galling....which will ruin your day and motor. I understand that Malhe did make some Nikasil CIS P/C sets but have been unable to nail that down. In any case, Nikasil cyls are what you want. Then you can use any piston you want.

I haven't seen Wayne Dempsey's book yet, but it's prolly pretty good.

I built my motor with 9.7:1 Shasta pistons and Solex cams.... on a good 7R case. There are a lot of bad 7R cases out there... or so I'm told. I can see no reason to use the RS spec 8.5:1 Malhe pistons other than for longevity (maybe). Malhe now makes 9.5:1 90mm P/C sets.....dunno what they want for em'...rumor has them around 2500 bucks.

I used case savers rather than timecerts and as I wrote, Divilar studs.....and Webers, MFI is a PITA and an expense that I don't need. The ignition is MSD with a RS spec dizzy. The motor makes good power and runs cool. It does lead a hard life. If I can get 2 or 3 more seasons out of it, I'll consider it a success.

If your not building a car to run in some specific racing class, I would build a 3.0 or 3.2L motor and get away from the mag case. I'm not a huge fan of the mag case motors. I just kinda fell into a gud deal on this motor and found a home in SCCA F Prepared for AX. Shit happens.

I have a set of those from a 2.7 for my next motor, so they do exist. They have "Mahle" cast in the base of the cylinder. I can't tell you the exact year engine they came from, though.

James:
Did you do the magnet test on them?

N.B., the "rule of thumb" on twin-plug setups is that you can run about a full point of compression more on the same fuel without pinging than with a single-plug setup.

--DD

I just bought my copy. I have to say, it is SUPER GOOD !!! Wayne have done very good job. This is IMHO highly recommended. It makes very good package of information with BA´s handbook.