402 stroker ino

[speedfreak]

402 Stroker Build Questions

 

--------------------------------------------------------------------------------

 

i have a 04 rcsb 2wd with a 5.3 with whipple. i recently purchased a 01 6.0 engine complete with 10,000 miles on it. i plan on ordering slp's 402 stroker kit and installing my whipple on it. my questions would be what cam and heads combo would work the best? i use the truck daily and drag race on the weekends-(normal gearhead). right now i have the ls6 valve springs in my 5.3 that i plan on using, yank 3000 converter-which i been told to take out and put the stock converter back in with the stroker to make better use of the low end torque. i don't want a real lumpy cam just something mild and i would like to stick the the stock 6.0 alum. heads. i want to make 450 to 500 at the rear wheels, i am at about 375 now with the 5.3. any help would be great. this is my first engine build and i know there are some experienced pros out there to help a rookie make some good old american horsepower! thanks

[zippy]

i would just use the stock 6.0L heads with an XR281HR for your combo. i certainly wouldn't go back to the stock converter, but i would ask yank to re-stall it for your new combo. with the 402 and blower it'll be stalling around 3500 and you won't want that. 3000 actuall stall will be just fine with the 402 and blower.

[BenKey]

Personally, I would want a little higher flow than the stock heads. Maybe like a stage 1.5 at a minimum. 315+ cfm is the general rule of thumb for flow on a NA stroker, at least the consensus locally. All of that is not needed for a FI setup, but definitely more than stock flow. You should easily get more than your goal, unless you want to choke it back to where you want it.

 

 

Can the LS6 springs handle .573 of lift? Comp 918s are only about $120 and can handle .600 of lift.

[TurbochargedBerserker]

I'm going to weigh in here on not choking your cubes and planning on a set of heads as long as you can afford it. There are much easier and cheaper ways to get 450 hp than a stroker, so if cost is a major consideration, I'd go another route.

 

Stroker cubes are definitely not cheap hp.

 

Here's my argument. The stroker is going to need more air to make more power. I know FI provides more air because of boost, and while velocity is handled quite nicely by FI, flow is not. Much adieu is made about boost, but really we want power from boost, and that means airflow. Boost is just a measure of restriction in the manifold and intake runners, and while that pressure means you can force air into the cyclinders with better flowing heads you can force MORE air into the cylinders.

 

I'd say to get 450 - 500 hp, do a set of 10:1 pistons in the 6.0L and add a 75 shot for the added power and the intrecooler effect. On top of the motor and swap costs, you'd be adding about $1k, able to use stock heads, etc., and still make your goals.

[speedfreak]

when you guys say FI are you refering to fuel injection or something else.

sorry for the dumb question

 

thanks

[BenKey]

FI=Forced Induction (turbos, superchargers)

[zippy]

stock heads on a 402 with a mild cam are still going to have no problem getting 450-500rwhp down with the blower on there. i also see no reason to find a stroker to be a big expense. there are some decent mid price kits out there with parts that are much better than stock and will take all the abuse the average guy will throw at them. the ports on the 6.0L heads are pretty much the same as what you'd find on an LS6 which makes 405hp at only 6000 using a mild duration cam and is naturally asperated. if you do some searching on boards with dyno sheets you'll find that under boost the big dollar heads aren't as big of a hp adder as most would guess. they sure do look good when you buy them and for bench racing. the other idea is that later on down the road once you've gotten used to and bored with your current power level the short block is fine and you can upgrade from there.

[BenKey]

The least expensive stroker kit I have seen is the Eagle kit. Still runs around $2K. I think if the target is that much hp, then there are easier ways to get there before a whole other build.

 

I don't push for high dollar heads on a FI setup either, but I do believe that the stock heads are a little too restrictive. It may just a change of the valve size, if nothing else.

 

If I wanted only 450+hp, I'd drop in a mildly used LQ4, knock up the boost, and figure out a I/C for the supercharger, since Whipple f****D me on it originally. You could easily have that much hp out of a setup like that.

 

A stroker isn't worth the cost for parts, cost to bore cylinders, cost to build, cost to swap out for mid-400s numbers. But, aside from that, if money isn't any kind of concern, then a stroker is a nice way to go for anything.

[TurbochargedBerserker]

stock heads on a 402 with a mild cam are still going to have no problem getting 450-500rwhp down with the blower on there. i also see no reason to find a stroker to be a big expense. there are some decent mid price kits out there with parts that are much better than stock and will take all the abuse the average guy will throw at them. the ports on the 6.0L heads are pretty much the same as what you'd find on an LS6 which makes 405hp at only 6000 using a mild duration cam and is naturally asperated. if you do some searching on boards with dyno sheets you'll find that under boost the big dollar heads aren't as big of a hp adder as most would guess. they sure do look good when you buy them and for bench racing. the other idea is that later on down the road once you've gotten used to and bored with your current power level the short block is fine and you can upgrade from there.

<{POST_SNAPBACK}>

 

 

That's kind of exactly my point except I'd say don't do the stroker unless you want wild enough power to need new heads Much easier ways to get there on stock cubes ow.

 

Heck, an LQ9 with mild cam and blower is going to get in the low-mid 400s. Add a small shot (or nice exhaust on a blower system) and you're there.

 

That ZL402 kit is still $3k.

[j4nash]

one thing to keep in mind is that with a stock motor you can't run over 10-11 psi of boost. that is about as fare as our stock motors will go for the long run

[BenKey]

one thing to keep in mind is that with a stock motor you can't run over 10-11 psi of boost. that is about as fare as our stock motors will go for the long run

<{POST_SNAPBACK}>

True - 10 is easy. Personally, I would go 12, but maybe not many would.

 

Going to the 402 though, he won't have to worry about hitting that because chances are he'll never be able to come close. I know the whipple may be more efficient than a Radix, but based on the Radix results, don't think those kind of boost numbers would be attainable even with a Whipple. Not sure if there is anyone running that kind of setup on other sites.

[zippy]

if you have a 5.3 and you bought a 6.0L with 10k on it i'd just use it as is. if a rebuild is in the future i'd be looking at a stroker. rebuilding a 6.0L back to stock is pointless if a 4" stroke crank fits in there so easily. rebuilding a 10k mile engine is just spending money. i do see the reason to build a stroker for the simple reason of adding cubes. it doesn't have to be a 6 month 10k dollar project.

[bobjr]

Ok i a also wanting to do a stroker and was just wondering is there any sort of bolt in stroker kit? I mean one that wouldnt require a total rebuild? I did a stroker on my beemer and it was easy didnt even have to remove the motor from the car! Wonder if there is something like that here? 402-408 would be good for me plus the detriot speedworks turbo and i am set! Then just need to figure out how to fix whatever i will definately break on my tranny! LOL! I love this site thanx for all ya'llz help!

[BenKey]

Ok i a also wanting to do a stroker and was just wondering is there any sort of bolt in stroker kit? I mean one that wouldnt require a total rebuild? I did a stroker on my beemer and it was easy didnt even have to remove the motor from the car! Wonder if there is something like that here? 402-408 would be good for me plus the detriot speedworks turbo and i am set! Then just need to figure out how to fix whatever i will definately break on my tranny! LOL! I love this site thanx for all ya'llz help!  

<{POST_SNAPBACK}>

No such thing, at least for our motors. A stroker kit consists of a crank, rods, pistons, pins, and rings. All of which would require the motor to be pulled and completely rebuilt. Everything below your heads, internal to your block, is getting changed out. You'll also need block work. I didn't know that there was any motor that you could pull the crank without pulling the motor. Are you sure you put in a stroker crank?

[bobjr]

Yes i am positive it got a BMW turbo deisel crank and custom rods with high comp pistons! All they did was take the pan off take the guides and other things off from the bottom and shoved the whole rotating assembly up in there! And it screams!! Major autocross sleeper!