2.7 to 3.0 problems

[wrx paul]

I recently got a 3.0 engine for my 77s and have run into a few problems that I need advice on.
1st. The exhaust studs on the 3.0 are too short to use my headers from the 2.7. The headers have very thick flanges so I can feasibly grind them down to the right size at a local machine shop a friend owns. Or should I take my chances and remove the old studs?

2nd. The wires to the starter are different. The old starter (which I am using) has 2 connections, the main lead and a spade terminal for the solenoid. The new engine has 3 wires (a yellow with blue stripe) that I don't know what to do with? Is this a cold start system? Do I need to connect it to something?

3rd. I had the old engine on a msd system. The new engine came with the 6 pin Bosch unit. Should I keep using my msd system or go back to the Bosch? If I keep the Msd I'm not sure which wires to put the trigger on to. The old way used the white wire to the points but the new engine has a points-less distributor. I read the Msd manual and it has 2 wires for this but I dont know which one goes where and what polarity? Anyone have experience with this?

[wrx paul]

Please Help!!

[pbs911]

I woudl go ahead and remove the old studs using the two nut removal method. Replace with the proper length and use antiseize on the threads.

The others I don't know. I only recall 2 wires to be hooked up to the starter on my old 3.0.

[Otto]

Have you ever noticed that I only post when nobody else knows zup. The extra wire is for the cold start. Leave it where it is, it works with a thermal switch that only works below a certain temperature.
Also, leave the six pin CD in the system.

[MotoSook]

Paul (new paul), I've done the 27230 thing on my car. Otto is correct.

The Bosch (better) unit stays, and you'll have to pull the tach wire out of the 14-pin connector and splice it into the tach wire directly.

The third connector on the 3.0 harness goes on the start too. It energizes the cold start when the key/start is energized.

There have been numerous posts on both topics before, so run a search and ask about anything you are not sure about.

BUT! first join Gruppe B! http://www.gruppeb.org/

Good luck. You will be pleased with the 3.0!

Wuf! Wuf!

[mb911]

MSD The green and grey wire conection is for the hall effect sensor off the 3.0 distributor. I like my msd box as it is a clean install and cheap as compared to the bosch unit.

Ben
77 911 3.0
75 914-6 2.7

[wrx paul]

So you're saying I leave the extra yellow and blue wire disconnected or do I splice it onto the solenoid with the other yellow wire (I currently only have a terminal for one wire)
As for the MSD which wires do I connect to the distributor. The MSD book lists one as + and another as - but not sure what the output wires on the distributor are and what polarity.
Thanks for the responses guys!

[Otto]

Just wait till that unit takes a big &*%# and leaves you stranded in Bum#%&* Iowa.

[bmwr60]

I take offense to your Iowa comment. In fact, there happens to be some good Porsche mechanics in Iowa City and Des Moines. My '77 Porsche 911S is in North Liberty, 10 miles North of Iowa City.

[Otto]

O.K., I meant Bum#%&$ Alaska. (I knew some geek would ding me on that)

[Don Wohlfarth]

LOL
Otto only posts when there's something that needs someone who's BTDT and he gets a lurker who's so offended that he makes his first post defending the fine state of Iowa.

[mb911]

wrxpaul

Green and purple wires go to the dist. They should be marked + and _ in the msd book if you can't find let me know. Then once you know which is the "positive" lead should be the inner wire on the green cable coming from dist connect the 2. The outer sheild from the dist green cable should go to the - side. If you like Email me direct for the complet 3.0 msd set up.

Ben
77 911 3.0
75 914-6 2.7

[surflvr911sc]

Originally posted by wrx paul
So you're saying I leave the extra yellow and blue wire disconnected or do I splice it onto the solenoid with the other yellow wire (I currently only have a terminal for one wire)

if your engine still has CIS (I'm sure it does if you have this wire) then hook it up w/ the small red wire (I think it's red) that hooks up to the small terminal on the starter. This energizes the cold start injector (whatever) when you are cranking. Just splice it in w/ the other one and no worries.

[Gunter]

Splice both wires together to go on the starter solenoid spade. (Normally there are two spade connections on SC solenoids) One (blue/yellow) is for the cold start (it activates the timer) and the other (yellow) comes from the ignition switch to activate the solenoid. I would go with the Bosch CDI instead of MSD. The studs are a *****!!!!!!!. You need some heat to break the LocTite stuff and then try double nut.

[wrx paul]

Thanks for the help guys. I think I have everything working at the moment. I ground a little off the back of the header flanges and they went on with a little coaxing. The started wire seems to be fine after I hooked up both to the existing spade terminal.
Right now I am using the Bosch box for the ignition untill I make sure everything is ok then I'm gonna put the Msd box back. But right now I'm not getting anything on my tach. Is the 27 tach different than a 30 tach or does it just need some rewiring?
again thanks for all the help!!!

[ruf-porsche]

Originally posted by Otto
O.K., I meant Bum#%&$ Alaska. (I knew some geek would ding me on that)

Why wouldn't you think some geek from Alaska wouldn't ding you for using Alaska.

Why don't you use Baghdad, I don't think you're gonna offend anyone from Baghdad. I think the only Porsche owner in that country has departed.