should I get a 2.2 or 2.5 common block

[ForceFed Wraith]

Pre ignition would be caused once again by a hot spot on the head, am I correct?

BTW, I do have an intercooler and during some cold nights, the IC pipe was very cold...which is why I'm even more surprised that the piston melted.

I have an air fuel gauge which was always pinned at the second / third rich bar under WOT. An EGT gauge was "comming attractions".

pardon my ignorance but what is dwell time?

Also people mention the heavier wieght of the 2.2 forged crank but will also have a shorter radius. But the "planning" part is definitely where I fall short.

[glhsken]

Quote:

Originally posted by stampederunner Ok I read that page and found it very helpful thanks for the link, but I still have one question. The site says my pre-common block is good for a certin hp point but it doesnt say what. Basicly I want enough hp to see 13's I dont care if is 13.99 I want a 13 sec time slip! How much hp do I need and is my block good for it if not what would be a realistic hp and quarter mile time goal for a heavy daytona with a pre common block and still be a reliable every day car.

88 Shelby Z, 18 psi boost... 13.5 @ 103, mp computer, +20's fp 45 psi... easilly enugh done

[glhsken]

Stock 2.5L pistons are VERY prone to detonation.... 2.2's are much more forgiving.

[Stratman]

Quote:

Originally posted by cawcislo Some say 250hp is what the pre common block's are good up to then it's iffy. I'd say with a 3100 lb car or so you may run a 13.99. You'd have to cut some good 60' times though so nice slicks are a must. If you can cut a 2.0 60' time I think you can pull it off with around 250 hp in a pre common block. Any one agree/disagree?

88 stock rebuilt T2 2.2 block, very little port work and backcut valves on swirl port head, 15-16 psi, 2980 LBS on Fully furnished Daytona,
Stage 3 FWD Performance SMEC, stock intercooler, A-413,
Car dynos at 174 HP and 218 TORQUE:

BEST RESULTS :
1/8th Mile
60' 2.108
9.144 E.T.
75.64 MPH-- No 2nd gear, went from 1st to 3rd horribally!
21 inch tall street tires

BEST 1/4 MILE RESULTS:
60' 2.172
14.340 E.T.
96.04 MPH-- Had 2nd at the time--first time at a track, 4th or 5th pass
24 inch tall street tires

[GLHNSLHT2]

Quote:

Originally posted by ForceFed Wraith pardon my ignorance but what is dwell time? [/b]

Dwell time is the time the piston sits at it's upper most position. A longer stroke will make the piston sit there longer. The spark and fuel and flame front have more time to push on the piston. The bad thing is that it can fire too early while the rod is still completing it's rotation to the top. So a Shorter stroke motor can take more spark advance.

[GLHNSLHT2]

Quote:

Originally posted by glhsken 88 Shelby Z, 18 psi boost... 13.5 @ 103, mp computer, +20's fp 45 psi... easilly enugh done

And slicks?????

[glhsken]

Yes, slicks, sorry I missed the question

[ForceFed Wraith]

Quote:

Originally Posted by GLHNSLHT2 Dwell time is the time the piston sits at it's upper most position. A longer stroke will make the piston sit there longer. The spark and fuel and flame front have more time to push on the piston. The bad thing is that it can fire too early while the rod is still completing it's rotation to the top. So a Shorter stroke motor can take more spark advance.

Ah yes. Thanks. I did notice that when I rebuilt my 2.5 couple weeks ago and was rotating the assembly to ensure that everything is spinning freely. It had a noticably longer "dwell time" than my 2.5 V6 mazda motor.

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A longer stroke will result in a lower rod angle. And that will result in lower cylinder wall wear, am I correct?

Also, a longer stroke will give you a higher exhaust velocity as well. So will that spool a turbo quicker?

[macncheese]

Quote:

Originally Posted by ForceFed Wraith It had a noticably longer "dwell time" than my 2.5 V6 mazda motor.

a kickass motor. expensive, though. it was gonna cost me about $1800 in parts for one that i ran under water. oops.
tony

[ForceFed Wraith]

It definitely is a kickass motor especially for a N/A ... and VERY expensive. I have mine in a 96 Probe GT with a fairly large hybrid. It screams after 4000 rpm, I love it.

Much shorter stroke though. Plus less displacement per cylinder compared to TD motors. As a result, it has very little torque, but comes alive between 4500 and 7000 rpm.

[WantSum?]

not to hijack, but all motors includeing the 89 2.2T1 are common block arent they?

BTW, my friend has a MX-6 with the 2.5 init, full body kit, 17's, and he is just finishing the T4 ( i believe) turbo instal. i cant wait to run him and see what its got.

thanks nate