Author Topic: performance 2.5  (Read 2422 times)

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YJmechanic

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performance 2.5
« on: December 21, 2005, 02:59:37 PM »
Alright I'm going to try and remember all of this.  I started with my 94yj 2.5 which had a huge blow-by problem.  First was complete tear down.

 I started with the block.  The block was bored 60 0ver.  Any machine shop can do this. Next the deck was shaved to increase the compression ratio.  This is a variable depending on how high you want the compression to be and what you want this motor to do.  Mine is 10.5-1 and it needs high octane and gas milage is not great, but my jeep does almost no daily driving. Don't skip on little things like freeze plugs while you have it this easy to do.

Then is the cam and crank. The crank was turned 10-10 and repolished this is just to tighten up the bottom end and keep the motor smooth.  Horsepower can be lost just by motor slop.  The cam was custom cut by clifford.  It is a 426 lift cam.  They have the template for this and can be cut for anyone.  they also go up to a 502 I think and lower also.  This big of a cam needs a manual tranny or a stall converter to run and not shut the motor off.  I got hydro adjusting lifters also from clfford along with pushrods.  The bearings for both cam and crank are clevitte tri-metal bearings.  You can order them or have napa order them for you.  The 60 forged pistons came from york tool warehouse who can make or get just about any custom piston you need. I also got cromolly ring sets and shoulder pins from them.  Remeber when changing cam or crank the bearings have to change accordingly.  The connecting rods are original but have been smoothed and shot-peened.  This again creates better flow.  Also spend the extra money to have the bottom end balanced together.  The machine shop will check the crank/rods/pistons to make sure they work smoothly together.  Again power can be lost for sloppiness and engine balancing can fix that.  The oil pump and water pump are reman originals as I don't need more at this time.  Too much flow can be dangerous just like not enough.

The head is a factory head that has been redone, ported, and polished.  New valves and double valve springs installed along with bigger retainers and locks.  Most of that all came from clifford again.  

That's about all the internalls, outside is a borla header, custom flowmaster exhaust,  Accel 8.8 wires, blaster coil, poweraid tbs, injen ram intake, and optima batt.

That's about it.  This took a lot of time but not tons of money and now my 2.5 is as powerful if not more than a 4.0 but alot lighter.  I run down imports with 33's on and laugh. This is a big project though and without the right no how, You could spend a lot more money in having someone fix you mistakes, so make sure you are up to this kind of project before you start.  If I forgot anything please let me know and I get back to you.

jwrape

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performance 2.5
« Reply #1 on: December 21, 2005, 03:24:27 PM »
I am actually going to copy your formula for your engine. I am getting a warn-out block for $50 and will collect the parts as i go and start building slowly. My current  motor runs pretty good with the 4.0 TB and a conical air filter setup with a inertia ring on the fly wheel, but I really want the next motor to have some power but I don't want to do a swap, I would hate to cut the harness and make it look like crap under the hood so I figure I would build the 2.5L motor and 1)Keep the weight down, 2) keep the engine compartment clean and roomy and 3) Build a motor that no one would expect would have any power.

Every body that I tell i am gonna build the 4 banger tells me I am stupid or ignorant for keeping that dog, but I will love proving them wrong.

This engine with the AX15 behind it will be a nice compliment to the Jeep.

Do you remember what the machine work cost you for the block and the head work? Also to balance the bottom end?

I found something funny. My Dad's ski boat has the exact same GM block as the 2.5L but it says it has 140 hp stock. I would assume that extra 20 or so HP is from the block being balance already.

Offline Jeffy

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performance 2.5
« Reply #2 on: December 21, 2005, 06:13:05 PM »
Do you have a more specific list of parts and costs?  I'll trim and edit it later so it fits the format better.

Also, pictures would be nice.
Youtube Channel: https://www.youtube.com/channel/UCZNlr60GXH5OlKIFrT7P6mg
My Jeep: http://4bangerjp.com/forums/index.php?topic=2783.0
"If the motor car were invented today, there is absolutely no way that any government in the world would let normal members of the public drive one."

BK2LIFE

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performance 2.5
« Reply #3 on: March 25, 2006, 01:33:35 PM »
any more info on this?  how about cliffords info?  phone number? website?  any contacts?

BK2LIFE

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performance 2.5
« Reply #4 on: March 25, 2006, 01:33:51 PM »
any more info on this?  how about cliffords info?  phone number? website?  any contacts?

ragincajun

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performance 2.5
« Reply #5 on: April 02, 2006, 08:40:04 AM »
I am interested too in the list of parts, and costs.


Did you follow the buildup in the mopar engine book?

BK2LIFE

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performance 2.5
« Reply #6 on: April 02, 2006, 09:18:51 PM »
how much did you deck/surface the block, head?

BK2LIFE

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performance 2.5
« Reply #7 on: June 05, 2006, 10:48:08 PM »
hello? you there?