X2 i just cant wait to see what comes out of the barns and shops this fall or next spring i am sure there has been alot of top secret
stuff going on i have heard of at least 2 out of ohio and about 2 or 3 othersblock modifications for increase displacement
- Thread starter malibu795
- Start date
X2 i just cant wait to see what comes out of the barns and shops this fall or next spring i am sure there has been alot of top secret
stuff going on i have heard of at least 2 out of ohio and about 2 or 3 others
where is this going to end?? Come on guys, a billet block? Whats the point? Its not even a duramax anymore...
It's called Hotrodding Ben
At that point why not just swap a cummins in?
Nah, I'd rather have 8
I think they'd sell, some of us don't know when to stop...
GMC_2002_Dmax
The Still Master
The point is Ben, there is NO END !!!!
Those that are going in that direction like Keith and others are the pioneers.
Without them, shops like Socal Diesel, Inglewood Transmissions, EFI-Live and all the other "Characters" in this endeavor we would all still be driving a stock truck.
the point is ben, there is no end !!!!
Those that are going in that direction like keith and others are the pioneers.
Without them, shops like socal diesel, inglewood transmissions, efi-live and all the other "characters" in this endeavor we would all still be driving a stock truck.
AMEN
This an progressive addiction. A little is good but soon that not enough. You need more or something stronger. Pretty soon your wife is concerned. All this money is disappearing. Your spending hours in the garage.
Think how bad it would be with out a support group like this!
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actually, by most rule sets, if it can swing a stock-derived crank, it's still of the same origin and thereby legal.
Some say the p-pumped Powerstrokes that are out now (like Double Overtime mod truck and the Stroked Out 3.0 truck) aren't really powerstrokes. I beg to differ but it's probably like the argument of which oil is best, comes to personal taste/opinion.
I personally can't wait until Duramaxes like these are on the scene because the duramax is proving itself in all other fields of racing and pulling except the mod/open classes. Hopefully, with the onset of these new mod-class trucks, the duramax will be a threat in the top classes as well.
And yes, it takes, as 'bu said, cubic dollars to do it but dang gone it, if someone is willing to spend it to get a 7.3 to be the top truck in mod class, bygawd someone sure as heck needs to with a duramax. I sure would if I had the means. Kudos to those that can and are!! :rockon:
C-ya
C-ya
so thing the curve of the cylinder wall possibly messed up my wall thick ness readings. i did the following.
i cut out a piece of the wall so i could get a better measurment. the end of the guage shows 3.9 inches from the deck surface. or basicly were the pisotn crown would be if if piston corwn and deck surface was 0
this is the wall thickness. which varied form .262"-.265"
seeing this.. and knowing that under .200" wall thickness with out block filler is waiting for problems(pulling from gasser crowd). one could say the a .120" overbore is possible with out block filler. this would give room for said core shift during casting. a .120 over bore would net bor dia of 4.175 with stock stroke 426.7 ci block and 454ci with a 4.147" storke
another thing i was think about was doing a short fill in the block. filling the block up to the bottom of the freeze blocks would greatly increase cylinder wall strength along with increasing the main webs as well.. going with the law that less distance spanned the less metal one need to hold X weight. one could run the wall thinner ie bores of 4.2-4.25 pending how much filler they puting the block. mainly a race application. sled pulling drag race and the like
also i noticed that the piston crown even if one ran a 4.147 storker crank, it barely goes below freeze plugs. so with that said that reduction of coolant would not have a detrimental effect on keeping the block/engine cool since there is no combustion heat that far down. though on a heat soak condition the engine is possible to run 10-25* hotter and will take longer to cool off as well.
so am i out in left field with this?
i cut out a piece of the wall so i could get a better measurment. the end of the guage shows 3.9 inches from the deck surface. or basicly were the pisotn crown would be if if piston corwn and deck surface was 0
this is the wall thickness. which varied form .262"-.265"
seeing this.. and knowing that under .200" wall thickness with out block filler is waiting for problems(pulling from gasser crowd). one could say the a .120" overbore is possible with out block filler. this would give room for said core shift during casting. a .120 over bore would net bor dia of 4.175 with stock stroke 426.7 ci block and 454ci with a 4.147" storke
another thing i was think about was doing a short fill in the block. filling the block up to the bottom of the freeze blocks would greatly increase cylinder wall strength along with increasing the main webs as well.. going with the law that less distance spanned the less metal one need to hold X weight. one could run the wall thinner ie bores of 4.2-4.25 pending how much filler they puting the block. mainly a race application. sled pulling drag race and the like
also i noticed that the piston crown even if one ran a 4.147 storker crank, it barely goes below freeze plugs. so with that said that reduction of coolant would not have a detrimental effect on keeping the block/engine cool since there is no combustion heat that far down. though on a heat soak condition the engine is possible to run 10-25* hotter and will take longer to cool off as well.
so am i out in left field with this?
Attachments
bore it out by 1/4"????
Something doesnt seem to be adding up here, I feel like if this was really possible and logical thing to do, we would have seen it already done by now.
No offence Bu, but Im going to need to see Trippin or someone weigh in on this before I can make sense of it all. Without being a mechanical engineer I think it is very hard to calculate and figure out the logistics of such severe modifications. (which is why I dont even bother thinking about such things, because I dont have an ME degree)
again, just my own stupid uneducated oppinion
ben
.060 overvore is .030 off the wallsbore it out by 1/4"????
Something doesnt seem to be adding up here, I feel like if this was really possible and logical thing to do, we would have seen it already done by now.
No offence Bu, but Im going to need to see Trippin or someone weigh in on this before I can make sense of it all. Without being a mechanical engineer I think it is very hard to calculate and figure out the logistics of such severe modifications. (which is why I dont even bother thinking about such things, because I dont have an ME degree)
again, just my own stupid uneducated oppinion
ben
.120 oversize is .060" of the wall taken off
.250 oversize is .125" of the wall taken off
increase the radias by .060" increase the diameter by .120"
i dont think increasing the bore dia by .250 will work with out block being filled or by some other means of increase stregnth to the cylinder walls
my orginal question is how thin can the said cylinder walls be made before they break form the cumbustion pressure.
the only real answer i have gotten is dont know pick a bore size and go with it
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well in reference to what you said earlier about the big bore, shorter stroke (which I completely agree with)...do we even have the valvetrain stability to run the kind of rpms needed to take advantage of a large bore-stroke ratio? It's a pretty heavy valvetrain. I know it's the way to go on gas motors when racing, but it seems to me that Guy got the right idea by stroking these motors. Give's us more cubes, but keeps us in a reasonable rpm range.
All that being said, I would love to see some 7000 rpm dmaxs!
All that being said, I would love to see some 7000 rpm dmaxs!
nvmind, im stupid, I meant to say 1/8" not 1/4". You think 1/8" (.120) is doable without filling the block?
Bore vs stroke
When you bore a block bigger you still get tq. You have more area on the piston. Stroke in itself does not mean more tq over a bigger bore. Bigger bore means the heads work better(flow better). I think(for what its worth) that with the rocker ratio the duramax runs tht the valve train won't be that big of a problem. Yes there is weight there but little rocker ratio and light valves,spring, and retainers I think they will rev fine and stay together. The boost on the back side of the valve is small when you figure the square inch area of one valve with said spring pressure. I sure hope we can get these things to rpm I like high winders. Jeff
When you bore a block bigger you still get tq. You have more area on the piston. Stroke in itself does not mean more tq over a bigger bore. Bigger bore means the heads work better(flow better). I think(for what its worth) that with the rocker ratio the duramax runs tht the valve train won't be that big of a problem. Yes there is weight there but little rocker ratio and light valves,spring, and retainers I think they will rev fine and stay together. The boost on the back side of the valve is small when you figure the square inch area of one valve with said spring pressure. I sure hope we can get these things to rpm I like high winders. Jeff
it possible say under 800hp cylinder wall is still over .2XX" thick. that is with be taking gasser knowledge of keeping said walls above .200" in thickness.
i am sertianly not going to tell someone to go do it.
IF i went that big of a bore. i would think about doing a short fill with block filler to the bottom of the freeze plugs. to help support/stregthen the walls.
yes 03 i agree. bog bore small stroke equals high reving engine. as for valve train running that high... dont know. outside the rocker arm shaft there are aftermaket replacement/upgrade parts, pushrod, studs, billet vlv bridges, rocker arms themselves.
the stock setup bore to stroke is 1.04:1 bore/stroke 4.055/3.897
.120 over is 1.07:1 with stock stroke
.120 over and .250 stroker 4.175/4.147= 1.006:1
were as say a
cumming 5.9CTD is 4.02/4.72 .85:1
BBC 509 4.5/4 1.125:1
SBF 302 4"/3" is 1.33:1
with those engines posted. the dmax is still a very square motor. makes very good power and have a nice very wide power band
i am sertianly not going to tell someone to go do it.
IF i went that big of a bore. i would think about doing a short fill with block filler to the bottom of the freeze plugs. to help support/stregthen the walls.
yes 03 i agree. bog bore small stroke equals high reving engine. as for valve train running that high... dont know. outside the rocker arm shaft there are aftermaket replacement/upgrade parts, pushrod, studs, billet vlv bridges, rocker arms themselves.
the stock setup bore to stroke is 1.04:1 bore/stroke 4.055/3.897
.120 over is 1.07:1 with stock stroke
.120 over and .250 stroker 4.175/4.147= 1.006:1
were as say a
cumming 5.9CTD is 4.02/4.72 .85:1
BBC 509 4.5/4 1.125:1
SBF 302 4"/3" is 1.33:1
with those engines posted. the dmax is still a very square motor. makes very good power and have a nice very wide power band
its .040 danny not .40"
thats almost 1/2" and inch :rofl:.060 has already been done. from what i have been told
well hell, I like your idea. I just brought up the valvetrain stability issue since that's a concern in the high rpm gas V8s I've had experience with. I haven't really looked into the Duramax valvetrain much so I wasn't sure how high it could go. Then again, I suppose these problems might not actually concern diesels yet since we'd be spinning alot less rpm than a hi rpm gas motor (7000? compared to 9500+ on a gas motor)
its .040 danny not .40"
.060 has already been done. from what i have been told
maybe you should try1/2" and inch then
