engine swap looking for tach info

[matthewb]

I am currently doing an engine swap in my 86' 944. I am putting in a 4.6 liter DOHC engine from a lincoln mark viii. I am sure there are many of you out there that look down on this type of thing but I would still appreciate some help. I am nearing the time when I will be starting this thing up for the first time and I am wondering about hooking up the tach. What type of signal does the tach require? does it get a pulse for every revolution or for every cylinder fire or what? Can I recalibrate the tach for a V-8. I am just assuming I will have problems. Any information is greatly appreciated.

Thanks guys,

Matt

[hpservertech]

You might want to do a search on what those that have done the LT1 swap. I've never seen anyone putting a Ford engine in one of these cars.

[matthewb]

Yeah I have never heard of anyone doing one either. As far as I can tell I am the first but maybe I will find someone else who has. With the dual overhead cam it is a pretty tight squeeze in there.

[jkrustchinsky]

i can imagine the squeeze under that hood, i would love to see some pics,

[Razorback1980]

Tachs are usually calibrated for number of cylinders. Not sure how that will work but I am guessing it will read at half the rpms but again I'm not sure.

[jcommin]

From what I have read, the tach does need to be recalibrated. The how and what I'm not sure of.

[AKCJ]

I don't know much about tachs either. Some aftermarket units have a switch to go from 4 to 6 to 8 cylinders. I think the signal is from the spark - one pulse each time a spark plug fires.

Just wondering - would a tach from a (V8) 928 drop in? That might be the simple way to handle this.

[Razorback1980]

In theory, that should work. Not sure if it will fit or not though.

[matthewb]

Yeah the aftermarket tach I had in my other car had the 4,6,8 switch and it did count every time any spark plug fired. Does anyone know if the 928 and 944 shared the same dash design like the 928 tach would fit in?

I have heard that the guys who do the chevrolet swap need to recalibrate but I dont know how nor have I spoken with anyone who has ever done the swap before. Early on in the project I had a couple of questions and tried asking the guys at Renegade hybrids and they said "sure we will answer your question just send us a deposit on a kit". Well i'm not doing that.

If there are any V-8 swappers out there reading this please give me some input. If any of you know someone who has done the swap please ask them to help me out.

Thanks

[lovemy924S]

If you haven't already, try here...http://www.porschehybrids.com/php/index.php...

I'll probably be doing a swap in the spring/summer once i get the right car and sell the stuff i have to make the moneysS$$$...lol.

[Razorback1980]

You could always change the face of the tach. I "THINK" it would show half the rpms so changing the tach face to show that would be all it would take. You could repaint it or get one made that had the new calibrations on it. The new engine will be a low rpm engine I am assuming as most new ones are and therefore your tach that is in there should easily handle the max rpms.

[lovemy924S]

in a video i saw posted on youtube by BlackForestRacing (off of the porschehybrids.com board) he puts the camera on the tach and it's registering double because it hasn't been set up for the v8...not sure if this is what might happen with you...btw he had done a chevy LT1 swap.

[zedsn]

Hi, you may want to find an aftermarket universal tach that will fit into the hole. That might be the easiest and cheapest thing to do.

[JivenJim]

Stock Gauge re-cal http://www.nhspeedometer.com/
Pretty sure they can do that. Or go with an Autometer Tach and simply tap the neg coil wire, 12V, gnd.