Random Engine Block Question

[CJFusco]

I am trying to teach myself as much as possible about car engines (and 944 engines in particular) just in case I decide to invest in any future projects

Anyhow, I was wondering if the engine BLOCK is the same throughout the entire 944 range; I know there are many differences on the top end of the engine, but not sure about the block. If they are different, what are the differences.

Thanx, CJ

[aribop]

'87+ motors had studs on the front to the right of the water pump to accomodate the spring tensioner.
I've heard that later engines had improved oiling.
The later ones also had more bolts securing the balance shaft covers.

[CJFusco]

What I mean is, did the 2.5 NA, 2.5 turbo, 2.7 NA, 2.516v SNA, 3.0 S2, and 3.0 968 start off with the same basic block?

[Zero10]

No, once they went to 104mm bore they changed the insides of the block around, and I believe they siamesed the cylinders.
Also, the water passage change was done at the introduction of the 16V engine. Not a significant change.

That said, 2.5NA and 2.5turbo are the same blocks (provided they are the same year), IIRC the 2.7NA matches the 3.0-S2 and 3.0-968, but I could be wrong about that last one

[CJFusco]

I suppose that makes sense; in order to achieve the 3.0 liter displacement, it would take a bit more than just lengthening the stroke (although apparently you can build a 2.8 stroker engine by using a 2.5 liter block?)

The reason I am asking is because there is a 1988NA block available for very cheap. We are talking about tank of gas cheap... since I am toying with the idea of building a hyped-up 944 engine (not sure if I would consider 951, supercharging a stock engine, or a 3.0 liter unit) so the thought crossed my mind that I could always use this block as a starting point.

It would probably be cheaper just to buy a complete engine and make the necessary changes, but one must pursue all avenues of possibility before making a decision, non?

[Zero10]

It depends. If the block is available that cheap, take it. Worst-case you can sell it on here for more.
You could build any 2.5L out of it. Or stroke it to 2.8L. Lots of options. Since it's an N/A block it's probably not as beat-up as most turbo blocks seem to be.

[CJFusco]

Just curious, but does anyone have an estimation of how much it would cost to build a performance NA 944 engine... say, a 2.8 stroker with a racing head/camshaft?

[Techno Duck]

I think you would be looking atleast a couple $1k, mainly in the amount of time you would be spending at the machine shop getting everything done.

If you are serious about building a tricked naturally aspirated engine, i think you want to talk to this guy...

http://www.jmengines.com/index.htm

[Zero10]

3.0L crank - $1000-$1500
pistons - $800-$1600 depends on manufacturer and coatings
rods - $1200ish (can avoid buying pistons if you buy the right rods)
This is all ontop of a normal rebuild cost of ~$1000 for gaskets/bearings/other replacement parts
So, if you bought the right rods, a 3.0L crank and a full rebuild kit, you could possibly get away with only $3200. However, you would probably want to go with bigger valves and some other head work as well, driving the cost up more.

[CJFusco]

Hmm. But if this is a long-term project, with the money spaced out over a couple of years... not necessarily so bad

[fast924S]

CJ, you might also want to think about some changes to the oiling system, The pick up and return oil feeds are too close to each other, Half the time the fresh oil pickup is sucking in HOT foamy oil cus the return is soo close, So you might wanna think about playing with the tubes, Also welding a ring/sheild around the pickup this makes it suck oil from lower in the pan incase of Hight G cornering it will be less likely to suck in air.. Also if your gonna go NA then for more power your gonna want more displacment. Get some custom JE pistons and sleeves, I wouldnt play with the stroke to much, Im not a fan of stroker motors it puts alot more stress on the engine. I would go 2.7 with some good compresion and good flow and keep everything light weight so you can rev.

I know its alot of money but you might wanna try playing with some engine dyno sofware for your PC, some have all the specs for the 944 engine and you can play and mod with a virtual engine all you want. It might not be 100% accurate but it will give you a IDea of what differnt mods will do. The biggest problem is gonna be in the head with the single cam and only 8v you will reach a point where you cant get the head to flow good, then you gotta start sacifising low end power for high rpm power. If you have any question let me know I have been playing with my engine and ideas for about 2 years now

[seaboltman]

hell if you dont want that block, ill take it. Shoot me a PM if you decide not to take it.

[AA_Ezra]

It's contageous isen't it. Now i to feal the need to upgrade a few thing's here and there " while im in there " right? I belive somone on here posted an engine that broadfoot built for hime 2.5 block to a 2.7 or 2.8 Sodium Vavles X-drilled crank and some other stuff for about i say 3500-4500 but 4500 seems closer

[CJFusco]

Ugh you guys aren't doing a very good job of talking me out of this!

I have a couple more days to decide. Then I'll let you guys know. Thanks for the imput, BTW.

[Zero10]

Talking you OUT of this?.... whoops. I was talking you IN to this
Give up your life savings, build one crazy 944 motor, then enjoy it!

[CJFusco]

Well the situation is that I am 25 and a graduate student, not exactly making a ton of money and meanwhile paying for grad school out of my pocket, living in a split-house with quite a few expenses. Sure, I can get the block for cheap (but come to think of it, shipping might be $90), but will I trust myself not to empty my savings account in anticipation of getting a built engine?

Now, If I had a place to put a roller car to part out...

[Zero10]

Haha, I have 2 engine blocks in my basement taunting me as well......
I know exactly how you feel. Slight differences only. I'm 21, under-grad, and living in a basement suite.

[CJFusco]

It looks like the block is no longer available; I think I would be better off waiting to find a 3.0 liter block; if I want to build a displacement engine, I might as well start off from the best starting point.