12.8 @105 07 nnbs xcab vmax.. pics
12-10-2007, 11:13 AM
#41
370's/6L are more or less factory dimensions so they will run forever if you treat them well since they were engineeried like that. Boring out a motor will reduce tolerances between the cylinders and walls (not that big of a concern unless you overbore it though) but it's changing what the block was designed for. Stroking it causes the pistons to move further down and out of the cylinder walls which it wasn't designed to do. If the piston comes to far out the cylinder she will wobble at BDC and over time she will wear the bottom of the piston and you will consume oil, burn rings or possibly break a piston or a block.
Not saying it isn't safe to bore and stroke a motor just highlighting SOME of the drawbacks and why 408's wouldn't last as long as a factory spec'd 6L.
I'm sure others would chime in if you started a new thread on the drawbacks of boring and stroking for reliability but PM Jetmann or Richard@WCCH as they help...alot.
Not saying it isn't safe to bore and stroke a motor just highlighting SOME of the drawbacks and why 408's wouldn't last as long as a factory spec'd 6L.
I'm sure others would chime in if you started a new thread on the drawbacks of boring and stroking for reliability but PM Jetmann or Richard@WCCH as they help...alot.
12-11-2007, 09:19 PM
#43
A 4.0" stoke causes no problems with piston rock (or scuffing) or problems getting plenty of mileage out from the motor. The key is knowing your piston alloys and how to setup the motor for longevity. Any 408" my shop sells will have zero problems with rings, oil burning, broken pistons or blocks. Someones giving you bad info, dont believe everything you read on the internet.
<this is why the internet is a bad place to trust what you read, everyone is a guru>
12-11-2007, 09:39 PM
#44
That is incorrect....If your 408" burns oil, you need a new builder/machine shop. Wear is no issue if you build it with the right parts.
A 4.0" stoke causes no problems with piston rock (or scuffing) or problems getting plenty of mileage out from the motor. The key is knowing your piston alloys and how to setup the motor for longevity. Any 408" my shop sells will have zero problems with rings, oil burning, broken pistons or blocks. Someones giving you bad info, dont believe everything you read on the internet.
<this is why the internet is a bad place to trust what you read, everyone is a guru>
A 4.0" stoke causes no problems with piston rock (or scuffing) or problems getting plenty of mileage out from the motor. The key is knowing your piston alloys and how to setup the motor for longevity. Any 408" my shop sells will have zero problems with rings, oil burning, broken pistons or blocks. Someones giving you bad info, dont believe everything you read on the internet.
<this is why the internet is a bad place to trust what you read, everyone is a guru>
12-11-2007, 09:48 PM
#45
Taken from another thread which was debating the same issue between a 408 and a 370...
Again I just want to clear up that if built absolutely perfect any motor will last if thought out completely and built right. But these opinions are from some people who've all built 408's and had great success with them but are commenting on the drawbacks of a stroked vs a stock stroke.
Some of the same reasons devin listed above, along with oil burning, fuel consumption, cost, etc, etc. A 370 with a magna charger MP122 and 10 psi will get better average fuel mileage than a 408, and more reliability in the motor. Been there, done that, have the T-shirt, burned it.
Both strokers I had, sucked at idle sitting in a parking lot or at a stop light. The damn thing would shudder its *** off like the exhaust or something was hitting the frame. Along with normal driving getting SHITTY gas mileage with a tight 2600 stall(single digit mpg) and of course oil consumption. The oil consumption part wasnt indicative of your typical stroker though there were other outside factors that caused that. Im going with a forged 6.0 with a nice set of heads and a 122HH to feed my power need, Im done with the big CI stuff, I dont need 800rwhp to make me happy, its not like you can make that much HP hook on the street and be safe anyway. ...Just my opinion from what I have had/ridden/driven.
my 408 ran prety good and got 15mpg. that being said i dont see any point in spending the extra money on a forged crank unless you are going for 1000+rwhp and at that point you might as well go even bigger and do an lsx block. a factory iron block 408 seems like a set up that wont be all that popular in the future. 370(up to 1000rwhp) or make the jump and get a crank and block and end up with something like a 434(1000+rwhp)
i would go with a 122 or a turbo
i would go with a 122 or a turbo
12-12-2007, 08:39 PM
#46
I guess I am only basing my opinion on the dozens that we have sold/installed/tuned and dont have any problems.
forged piston alloy, assembly details play a part in something intended to go 50k+ miles.
No 408" we build burns oil, has side loading/piston/scuffing issues, nor gas mileage issues. Period. I only recommend 370" stuff for forced inductions applications standardly....
forged piston alloy, assembly details play a part in something intended to go 50k+ miles.
No 408" we build burns oil, has side loading/piston/scuffing issues, nor gas mileage issues. Period. I only recommend 370" stuff for forced inductions applications standardly....
12-12-2007, 09:06 PM
#47
Fair enough! Was just expressing my opinion and if I was looking for something durable and reliable I'd stay stock stroke!
That being said there's a reason why there's a lot of people running around with 408's N/A or FI. They are great engines if built properly.
That being said there's a reason why there's a lot of people running around with 408's N/A or FI. They are great engines if built properly.
Last edited by Spoolin; 12-12-2007 at 09:22 PM.
12-16-2007, 08:02 PM
#48
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I think there's more chance of a stroker(if not built superb) having problems than a stock stroke(not built superb), I believe problems in the stroker would be more noticeable. More risk, more payoff if done correctly. I'll vouch for LSinnovations they do immaculate work, and lots of it. Just my $.02
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