Tom M'Guinn

Ignition timing sounds very possible since his mechanic had him on the race gas maps by mistake, but I wonder if the motor had some uber-events when the chip board was loose -- like spark at the beginning of the compression stroke, etc. And since he found coolant in several cylinders, I wonder if the motor learned the hard way that coolant doesn't compress? Of course, I guess we can't rule out that 3" exhaust either. I also have to wonder about that check valve in the head -- I know they can get clogged, but wonder if that was really the cause of the problem? In any event, I hope Adam finds a new block and gets things sorted asap! Once you get the taste of a 3 liter at full boost, it's hard to forget...

Chris White

Way back when I was first ‘experimenting’ with the limits of 944 engines I did one try with the timing at 10 degrees more advanced than stock (street gas). It cracked a cylinder wall before I could say ‘that sounds wrong’! The crack in the wall then sucks in the coolant and does a good job distributing it around the other cylinders.

I don’t know the history of his Vitesse system other than it was a used part – but if it was set up for a short stroke engine (2.5 / 2.7) and then run on a 3.0 the timing may be too aggressive. Add that to the ‘race gas’ selection and you have way too much timing.

BTW – don’t toss out the cracked block – it may be a good candidate for sleeving!!

Thom

Without intending to wander OT (sorry Adam) :
I don't understand why some say the timing should be less agressive on a 3.0 than on a 2.5 while others such as Corleone say the opposite.
I understand that the piston accelerates faster with the longer stroke crank, which should mean less timing advance, is this correct?

Chris White

Keep in mind that we are talking about 8v engines. A turbo 16v 3.0 will like a lot more timing than a 8v 3.0

It has to do with pistons speed and rate of compression. There are a lot of variables in the causes of detonation – but I can tell you from practical experience that the 8v long stroke engines are a lot more fussy about ignition timing – much less safety margin.

Thom

Yes Chris I hear you, thanks, but my remark was aimed at 8V engines only. Is the acceleration of the piston the sole reason for the different timing? I mean, for an engine with the same CR and shape of combustion chamber?
I'm not sure but think the squish area is higher on the 104mm block, how much of an impact does it have?

apitts73

the VR stuff was for 3.0l...john reflashed the chipboard for my specific motor.

almost got the motor out today but ran into problem...
do i have to move the torque tube back if i want to pull the motor out the top??
or should i remove the radiator for more room to move the motor forward?
hope to have the other motor in the next couple days!!
thanks,
adam

JohnKoaWood

Pull the radiator, and the front belts / covers.. these out of the way will make the rest go easier..

And to answer a question you asked a couple times, but I didn't see any answers... NO the head off the 3L will not fit the 2.5 block.. the head on your 3L is likely a 2.7L head, not a 2.5 head, the coolant passages are different...

apitts73

thanks JohnKoaWood,

the head is a 2.5l, LR stage 2......would they have to change anything for it to fit the 3.0l?

Fredrik H

Yes you would, the water passages are different on the 2.5 and 3L blocks. To use a 2.5 head on the 3L you need to weld on a water passage (front left side of the head in cars direction)

gruhsy

Hey Adam are you sure your head is not the 2.7 liter head? I thought your first oil pressure relief issue had to do with the fact it was the 2.7 head. I could be remembering incorrect but I thought it was related to a 2.7 head.

Oh... and did you get my reply about exhaust etc?
take care,
Jason

apitts73

no, jason im almost positive its 2.5l....but i will confirm on monday with ML.
i do have a stock head in the garage...not sure of shape and then what about the solid lifter cam...will it fit with stock head? do they change the valves in the head to go with the solid lifter cam box?

when i rebuilt this 3.0l.....ill go with the 2.7l head.

for sure i got your response in the messages jason......will call today if you dont mind.?
adam

Bri Bro

I would go with the stock cam, you can pick up a used cam assembly and just bolt it on until you get the 3 liter going.
http://cgi.ebay.com/ebaymotors/Porsc...-/150485021047
LR states that there is machining involved with the solid lifters.
http://www.lindseyracing.com/LR/Parts/SOLIDS8V.html

apitts73

thanks brian,
so i cant use a stock head and the solid lifter cam together from the sounds of it....will my head w/ the 3.0l water passage conversion work on a 2.5l motor?
if not, then i guess i can buy a cam for the stock head....if that head is even usable...i will check in the garage today.
adam

apitts73

i forgot to ask......will the 3.0l flywheel and clutch fit/work on the stock 2.5l motor?
thanks,
adam

gruhsy

yes they are the same. bought my SPEC stuff for my 2.5 liter then decided on the 3.0 using the clutch stuff I bought to begin with

Jason