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View Full Version : Question for anyone running 4.2



BTobiczyk
05-26-2009, 07:48 PM
I am planning on rebuilding the motor on a 90SC auto that i just bought and was considering on stroking it out. Curious of who has this done on their car already and what kind of performance difference they are getting out of it. What compression, other tuning or parts, that kind of stuff.

Young-SC-Owner
05-26-2009, 07:58 PM
Search this... "David Neibert"

David Neibert
05-26-2009, 10:45 PM
Search this... "David Neibert"

I can't give any good info yet because I'm still working out the buggs and haven't completed the tuning yet.

David

BTobiczyk
05-27-2009, 01:02 PM
well so far how have things been looking? Are you using a cast crank or do you have a forged one?

David Neibert
05-27-2009, 02:59 PM
well so far how have things been looking? Are you using a cast crank or do you have a forged one?

There isn't a forged 4.2 crank available and a billet crank was going to cost about $2300, so I'm using the cast 4.2 neutral balance truck crank, Scat rods and Wiseco custom forged pistons. XR7Dave (aka Dave Dalke) supplied the parts and built the motor.

Things are looking very good, except for having problems with the motor running too hot. BTW, I don't think the cooling problems have anything to do with the increased displacement.

David

old_coot
05-27-2009, 03:07 PM
I built one last year for the shootout---I won fastest stock appearing with it.
I used a stock truck crank, stock SC rods, and a set of replacement hypereutetic pistons for a 98 mustang 3.8 V6.---Yeah I took the cheap route but I knew with the stock MAF, throttle body, and M90 I wouldn't be straining anything. I managed to run a 13.82 with a single intercooler and only making about 9 1/2 pounds of boost.--That was on a set of worn out 225/60/16 el cheapo tires too.
I am currently redoing the engine to pull a bit of compression out of it since doing what I did made about 9.4 to 1 compression. I am going to have a bit of a dish machined into the top of the pistons, also I had to have .200 cut off the center counterweights on the crank to clear the piston skirts because I used the stock SC rods.
I did manage to build the engine for about 1400 bucks so bang for the buck was pretty high.................Dan

BTobiczyk
05-27-2009, 11:21 PM
no problems with the cast crank? I have heard rumors of them not being able to hold up to the boost. That was my main concern before starting the build

David Neibert
05-27-2009, 11:36 PM
no problems with the cast crank? I have heard rumors of them not being able to hold up to the boost. That was my main concern before starting the build

That has always been my concern too, but after seeing several the v6 mustang guys make 500-600 rwhp without breaking them, I decided to give it a try. Several of them have busted pistons, bent rods and even cracked the block, but the cast crank always seems to survive.

David

Roadhawg
05-28-2009, 10:04 AM
I'm running a 4.2

BTobiczyk
05-28-2009, 04:17 PM
Where did you get your crank from? Just an oem one or did you get a race prepped one from supersix or something? I am going to be tearing mine down in the next few days and im trying to make all the decisions on where to go with it.

Roadhawg
05-28-2009, 04:38 PM
Where did you get your crank from? Just an oem one or did you get a race prepped one from supersix or something? I am going to be tearing mine down in the next few days and im trying to make all the decisions on where to go with it.

A Ford factory 4.2 truck crank, 6.125 SCAT H beams and a set of Ross forged 8.5:1 pistons.

BTobiczyk
05-28-2009, 05:05 PM
What kind of numbers does it make? what else do you have done?

Kurt Sunday
05-28-2009, 06:46 PM
Didn't Dr Fred build a 4.3 with great results. Anyone remember the details?

J dot Miller
05-28-2009, 08:41 PM
BTW, I don't think the cooling problems have anything to do with the increased displacement.

I dunno about that. When I put the 5.4L in the Cougar a new radiator was only good for 2 years. After that amount of time it was fouled enough to start running warm, forcing me to change it (Thunderroad has my last one). This problem occurred when She was less than 30HP over stock. Finally I gave up and installed a Griffin. Glad I did now with much more HP I need all need all the radiator I can get.

So I ask the question: How old is your radiator? If it is 3+ years old? Is it stock?

old_coot
05-28-2009, 11:03 PM
I haven't had any overheating problems with my car and was very surprised to get 24 mpg on the highway----it made 271hp and 375 torque last time it was dynoed...but the power went away quick after 4500----just not enough air flow for the increased cubes due to the restricted intake and intercooler---I'm going to try doctoring that a bit for next year............Dan

David Neibert
05-29-2009, 12:01 AM
I dunno about that. When I put the 5.4L in the Cougar a new radiator was only good for 2 years. After that amount of time it was fouled enough to start running warm, forcing me to change it (Thunderroad has my last one). This problem occurred when She was less than 30HP over stock. Finally I gave up and installed a Griffin. Glad I did now with much more HP I need all need all the radiator I can get.

So I ask the question: How old is your radiator? If it is 3+ years old? Is it stock?

It's a Griffin aluminum radiator that is about 5 years old (less than 20K miles since installed) and in excellent condition. Coolant was changed just about every year because stuff like cam swaps or engine being pulled from the car for upgrades or repairs.

David

deathvenom
06-21-2009, 12:17 AM
i also have a 90 sc auto. stock but all new parts minus the block. i got it running and then i lost a ring #2 piston. now here is my idea: buy low mileage 4.2L from lkq $275 "u-pull it" put my new heads, intake, brackets, m90, and sensors "stock ecc and efi". i know there will be harmonic balancer issues. and i have a hypertech chip. what am i missing? will the heads and intake fit? i plan on keeping the 4.2 block internals all stock and keeping the 4.2 fly wheel. will it mount to my trans? :confused:

bowez
06-21-2009, 08:25 AM
Looks like 4.2 with forged rods may be a good replacement engine if can't get a SC block.

deathvenom
06-21-2009, 08:42 AM
i found this just needs sc heads and intake
<embed src="http://videos.streetfire.net/vidiac.swf?video=397fd8f0-ae78-49de-bbc9-e4d5ff4c62b0" width="428" height="352" allowFullScreen="true" type="application/x-shockwave-flash" pluginspage="http://www.macromedia.com/go/getflashplayer"></embed><br/><a href="http://videos.streetfire.net/video/1996-Thunderbird-42L-V6_40296.htm">1996+Thunderbird+4.2L+V6+Stroker</a>:cool:

deathvenom
06-21-2009, 08:53 AM
4.2l with sc heads and the M90 which cam would give me more power from 2800-3200 rpm the stock 4.2l or the stock 3.8l sc?