Head Conversion?

[YeTi]

I have a blown head gasket and possibly a cracked head.
i was thinking of just getting a whole new head/manifolds. i was wondering if Porsche made any 2.5L DOHC heads and was wondering if i could fit a DOHC head from a 2.7L on my 87 n/a. i was also wondering if i would need a new ecu to have a DOHC...
help.

[930guy]

You would definately need a new ecu-sounds like alot work. Want a nice upgrade? have a stock head ported out and polished. I have done this to many 944 heads and very good results on a flow bench. Have your head proffessionally checked for cracks it is uncommon for a N/A head on a 2.5 engine to crack(unless it froze)

[87Porsche951]

Only DOHC head made for the 944 was the 944 S2 which had a 16V DOHC. I dont know if you can swap the heads. I do know you can sway it on a 951 but the head has to be altered. I dont know if you need a different ECU. Not sure if the 944S2 has VarioCam or not.

[YeTi]

no, it doesn't. vario-cam made its debut in the 968's.
um, i believe that the 88's or 89's have DOHCs. but i think it might just be the S model.
and about the cracking of the head... it did start behaving like that after the first freeze of this year... (eek?) how much is the port & polish?

[87Porsche951]

the 88 & 89's dont have DOHC im almost sure of it. Only 16V DOHC head on 944 was the S2. I dont know about the 90-91 models cause they stopped importing them to US after 89 and there isnt much info on those years. i do know later 944's from 2.5L to 2.7L. If teh S2 head wasnt ariocam than i dont see why you would have to get a different ECU since the head would be mechanical not electronic controlled. I have talked to people about doing a head swap and they all tell me that it isnt worth it unless your building a race motor but I say go for it if you need a replacement head anyway and you can get a good price on the head and able to alter it to matte up. If the price to do all this is sky high i wouldnt do it for it wouldnt be worth the money and hassle.

[xjoeharperx]

Ive learned from experience, when the top engine of that engine goes..its almost time for the bottom half..Replaced the head and 3 different 944's and within 2 months all of them had bad rod bearings...
Maybe just a coincedence but strange i think...

[87Porsche951]

Only thing i had to replace because of a failure so far was two headgaskets. blew one and the second one failed cause the shop didnt install it right. and i burned up my clutch.

[YeTi]

when your head gaskets went, what did it act like?
because i am having major loss of power around 3000 rpm's when its cold (it almost dies), coolent loss, high oil consumption, emulcification (oil and coolent mix) at the top of the oil fill spout, and stuttering. and the loss of power lessens the warmer it gets... i assume that its because the head is warming up and expanding.
does any of this sound familiar... or have i diagnosed the problem wrong?

[87Porsche951]

If you have coolent in your oil wouldnt they be a signed of a blown head.

[930guy]

heres some light on your question-1st off 16 valve heads came on all "s" models which started in '87(trust me, mr. 951 man, I own one) 2nd-the 16 valve head will physically bolt on to the regular 8 valve lower end but the intake will not. Because of the HP increase and amount of fuel and air increase you would have to have your ecu reprogrammed. 3rd if you had a 16 valve head sitting on your work bench ready to go and you wanted to spend alot of money making it work I would say go for it! BUt... the 16 valve heads are some what rare and usually expensive to buy. My neighbor bought one off e-bay for $800 and had to have new valve guides installed and complete valve job done, all said and done he had $1400 in to it. I speak from experience when I suggest sticking with a 8 valve head, port out the head and polish the ports and have a quallity valve job done, buy a FR Wilk chip and a free flow exhaust and enjoy the reliability and HP increase.

[xjoeharperx]

Oil in the coolant is a sign of a cracked block.

[930guy]

Oil in the coolant is not a sign of a cracked block its a sign of bad oil cooler seals or a bad head gasket!!!!!!!!!

[YeTi]

mixed results make my cranium hurt!
so... cracked head, or bad head gasket?
i'm looking for a head and i've seen one for $245. is that good, or can i do better?
how much is it to port and polish?
thanks guys...

[930guy]

depends on the shop. I usually get about 250 to do the job, but I would imagine all shops are diffferent. If you have some time and some tools you can order a complete kit from Goodson for about $50

[xjoeharperx]

Go to http://www.paeco.com/ and order a free catalog..it will have all you need to build up the engine...thier parts are of the upmost quality too..