stroker kit 4.2

notorious sc

Registered User
Is the 4.2 stroker worth the expense????I was conteplating to bore my block .020 over with 10.1 copression or just order a full stroker kit with .020 over pistons and 10.1 copression?What kind of HP can I make with a stroker kit,cam,P&P heads.Advice would be appriciated. THNX
 
Not sure about the power levels, but 10:1 seems a little high for a Supercharged engine unless your running race fuel or nitro or something. At the most, I wouldn't personally go any higher than 9:1 with a Turbo or SC engine.
 
Been there - Don't waste your time stroking to 4.2 or 4.3. It's not worth the hassle.

Can you elaborate on what made it such a hassle?? How much does the stroker increase displacement?? Is the 4.2 block really much different from the 3.8 SC block?? Are the mounting locations and such different?? Just curious as to what the problem you ran into were.

Just put a Stroker 302 in a friends Mustang. Increased it to 331. He was talking about a stroker for an SC, but I wasn't really sure what the benefits might be. After I get my 35th (non rusty edition) finsihed and on the road, I may work on the rust edition and build up a motor for it..
 
To do it right, you need a forged crank because the cast ones are more prone to breaking due to the increased torque.

The 4.2 block is very similar to a 3.8 but wall thickness is more uniform, stronger ridges etc. You need to fabricate a bracket for crank sensor and reposition the dipstick. Engine mount, accessory brackets all fit. Knock sensor may not work.

The process to have it built, rebuilt and rebuilt took far too long and too expensive. Balancing the rotating assembly is critical and there are a few philosophies on how to do it (so I am told).:rolleyes:

Tuning has been a PITA. And I am not impressed with the performance given all the MP bolt-ons, underdrive accessory pulleys, overdriving sc 15%, bigger injectors, lightning maf, 8.7 cr ...
 
To do it right, you need a forged crank because the cast ones are more prone to breaking due to the increased torque.

The 4.2 block is very similar to a 3.8 but wall thickness is more uniform, stronger ridges etc. You need to fabricate a bracket for crank sensor and reposition the dipstick. Engine mount, accessory brackets all fit. Knock sensor may not work.

The process to have it built, rebuilt and rebuilt took far too long and too expensive. Balancing the rotating assembly is critical and there are a few philosophies on how to do it (so I am told).:rolleyes:

Tuning has been a PITA. And I am not impressed with the performance given all the MP bolt-ons, underdrive accessory pulleys, overdriving sc 15%, bigger injectors, lightning maf, 8.7 cr ...


Good info. Does it use all of the accessories that are on the 3.8 (brackets/timing cover, etc?? ) So if you had to do it again, you would go with a 3.8 block then?? How different are the heads for a 4.2 than the 3.8?? How many bolts hold the heads down?? Is it the same number as on the SC?? Did you go with a stroker package, or construct it yourself??
http://www.need-4-speed.com/V6%20Performance%20Corner.htm
 
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It uses all of the accessories that are on the 3.8 (brackets/timing cover, etc) - all bolted up the same way, except for the differences mentioned. Used 3.8 heads but ported and welded. Same number of bolts. A lot of work on the intake. Have kook midlength headers. The plan was for an additional 4 studs each side but he didn't deliver on that.

The engine builder I used sells a 4.2 l stroker package - no names will be mentioned.

The engine builder indicated there would be huge gains in torque and horsepower at the wheels but it did not materialize and its been about 4 years of hell.

I am aware of 2 other people who are also struggling with their setup. Theoretically it sounds like a good idea however others have come up with more power in a more reliable package so if I were to redo it, I would use a blown v8 or go with Steigmeier heads and an mpx blower with a strong 3.8 bottom end. Besides too much torque and low traction does not get the car going faster - a stock SC can spin tires.
 
sounds like you had WAY more issues then normall.

take a 4.2 crank,rods and pistons. put it in a SC block. put all your other stuff on roll.

it increases the size by 30CI.

i love my 4.2L
 
sounds like you had WAY more issues then normall.

take a 4.2 crank,rods and pistons. put it in a SC block. put all your other stuff on roll.

it increases the size by 30CI.

i love my 4.2L


Are you saying to put just 4.2 stuff in the 3.8 block, or put 4.2 stroker stuff in the 3.8 block?? The 4.2 block is no good??
 
Are you saying to put just 4.2 stuff in the 3.8 block, or put 4.2 stroker stuff in the 3.8 block?? The 4.2 block is no good??

4.2 and 4.2Stroker is the same lol.

the 4.2L block is the same as the 96-00 block and 01-04 block. its fine.
 
So your saying then all the 4.2 stuff can handle upwards to 25psi or more of boost etc?

a 4.2L crank. with good rods and pistons will make lots of power.

i have ran 30-34psi and made 638rwhp through a C4.

the stock rods and pistons are junk.
 
The difference is the factory SC crank is steel. I dont think its as much the power level as it is the amount of stress put on the front snout of the crank with a roots blower.

A turbo doesnt give that type of stress
 
The difference is the factory SC crank is steel.
The correct statement would be that the SC crank is FORGED steel vs. the 4.2 being CAST steel. Both are steel. Either one is a lot stronger than a stock 5.0 cast IRON crank. Personally I have no reservations running the 4.2 crank at a decent amount of boost via a supercharger. But yes, a turbo is much easier on the crank.
 
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