i believe the general consensus is that the stock 2.7 can handle around 300hp before things start to go wrong. obviously though there have been exceptions. the key to everything of course is tuning.

 

it can hold a pretty decent amount approximately 300 WHP (so they say) although many will disagree, (mostly those from PR )

 

depends it can take 300 whp from the sniper easier than 300 whp from the assasin due to cfm pushed. also the turbo guys are all running diesel *** intercoolers vs a heat exchanger that has bout 10 inches to cool the air b4 it enters the combustion chamber vs a **** ton of piping.

not to mention the higher hp turbo set ups have the boost coming in later in the higher rprm range.

also tuning is absolutely key

 

Actually an Aluminum block is a desireable thing. Al block engines only really start to get weak in the serious HP ranges. The only other disadvantage with them is that you can't bore them too much, but obviously no one has tried to do that. lol.

 

the good thing about the 2.7?........... nitrous, it loves the bottle, i ran a 120 wet shot for years with only a few minor things, UD pulley , CAI , cat back. never even put a tuner on it and made 314WHP and 348WTQ,, i raced it ALL THE TIME and when i took the stock block out to put the NGM race motor it looked like brand new. several people have ran 150 wet shots on stock motors several times

with all the playing i have done on the tibs, bottle- SC- SC and meth - SC and bottle - SC and bottle and meth. ill put my money on the spray and say that coreectly tuned it will hold together as long as the WHP or WTQ doesnt break 400 then you will be good to go on an all stock block as long as you dont try to do 200 mph of corse lol

 

Thanks for the numbers.

 

you cant use an air to air intercooler on a roots style SC so you have to use water in an air to liquid intercooler to cool the charge

the week point is mainly the rods unless you get knock then its the ring lands

and aluminum blocks are just fine for power ( gm's LSX motors make over 1000 all the time)

 

There are good things about the delta? I thought the block was made out of styrofoam

 

supercharged: 300whp for the pistons and 400whp for the rods, you exceed that and it is probably just a matter of time (ring lands seem to not like running at over 300whp, apparently because they are too close to the top of the piston)

turbo: can't really say cause if you only boosting between 5000 and 6500 rpm you might be able to make big power (over 350whp), not be so hard on the block, and probably run a 14.0+ 1/4 mile

 

I'm not sure where people are getting more than 300HP; I'd like to see some dynos of those cars and a bit of history on how long they lasted.

"Good" things:
Lightweight
Dissipates heat fast
Responds well to boost (see "meh" things for R/S ratio)
Heads flow reasonably well

"Meh" things:
Rod/stroke ratio is marginal; more amicable to N/A than the 4cyl
Mediocre cylinder filling, partially due to rod/stroke ratio
Crank main bearing cap bolts are anchored in the block by only two steel press-fit dies

"Bad" things: The power limit of these blocks is all on the bottom end...
Crank main bearing caps are relatively small
Crank main bearing caps aren't girdled and are only 2-bolt design
Crank main bearing caps in the center (heavy load-bearing) section are an M8-sized bolt (thin)

The problems come when you get lots of cylinder pressure pushing down on the crank. A V6 has a very short crank length, so you only have four main bearing caps to hold it on (Pulley End -> Cyl 2/3 gap -> Cyl 4/5 gap -> Transmission end). So each main bearing cap is responsible for more load than, say, the 4-banger motor (or an 8-banger).

Unfortunately,as the block is aluminum, you don't have the same structural rigidity as you might on a cast iron block. Not a problem right, because there are aluminum blocks making 1000hp out there? Sure there are, but they've got four bolts holding each bearing cap onto the block, and all of the caps are girdled (ie - attached to one another) so that other less-loaded caps can help offset the load of the others.

Further, while 8mm studs aren't inherently a bad thing, the problem is with the "gripping force" of the matching steel dies inserted into the aluminum block. A bigger bolt would need a bigger die, which would present more surface area to grip into the block under severe load.

The "clif notes" is something like this:
The Delta block will work very well for N/A application -- opening up the head (cams, valves) will do wonders, as many of you already know. They're best suited for keeping the torque to a reasonable level and using RPM's to stretch your horsepower curve out as far as you can get it.

Unfortunately, boosted applications are not so lucky. They will respond well to boost, but they will quickly reach their structural limit after the ~300HP mark.

 

wrong .

 

Wrong.

If you don't need to support your argument, then neither do I.

 

A spreadsheet does not support anything about my post being wrong.

Let me make it even easier for you and the folks from PR: the block isn't structurally safe at that power level, and no amount of rods and pistons will "solve" it. The reason that the four cylinder motors go so much further (with reasonable reliability) is because they are far more structurally sound due to block composition and design decisions at the bottom half of the block.

Design decisions such as girdled crank bearing caps, cap bolts that are M10 in size, caps that are wider and thicker, and of course the simple design effect of a four-cyliner motor having one additional cap versus a V6 motor. The 4-cylinder (by comparison) has more load support and handles uneven load distribution far better.

These are indeed things that are bad about the Delta setup, some of which are shared with other V6 motors as well. By pure virtue of load capacity, an inline motor will be capable of higher load than a V-motor, all other items being equal.

 

A spreadsheet does not support anything about my post being wrong.

Let me make it even easier for you and the folks from PR: the block isn't structurally safe at that power level, and no amount of rods and pistons will "solve" it. The reason that the four cylinder motors go so much further (with reasonable reliability) is because they are far more structurally sound due to block composition and design decisions at the bottom half of the block.

Well sorry to inform you Mister wrong (and you are way off BTW) Chadolff ran his block stock(except for pistons only ) at 400 whp without any issues at all , and I do mean no issues and he musta had at least a bazillion passes on that motor plus the retarded amount of dyno pulls on that thing . the only reason his motor popped was because he decided to see how fast he could get his 1/4 mile pass down to by running the 50 shot of nitrous from start to finish I ran a stock block before building this motor on 100 shot nitrous with just I/H/E and a tune (a very low 13 sec ride might I add) for 2 yrs straight and that was about 45 -50 bottles run through the motor and no damage to the motor whatsoever(infact I still have the block to this day)Now this motor I have has been on the road now for nearly 3500 miles at over 400 whp and I'm not having any issues with this one either, granted I'm running a better bottom end >But that's because I'm running a Mp 90 blower maxed out at 7500 rpm shift point (maxes out at 24.5 psi at 3200 rpm) and structurally safe? LOL where did you get your info from ya little egghead?The girdle setup on this block has been more than capeable of handling the punishment that we've been ponding to these motors, infact we're not having crank or main bearing issues we were havin piston meltdown and ringlan problems.Oh, and just one more thing.Chads car popped a rod because of the extra nitrous load , had he been running the rods I'm running his car would still be on the same motor and still running as good as ever. So you can keep youor spred sheets to yourself <eyesroll> I've peeled enough of these motors apart and built them enough to know exactly what they're weak points are and the crank isnt one of them, I really suggest if you want to offer info in these forums that you should do it based on experience not cliffnotes and book reading. And as far as 300 whp dynos ......since you like reading so much then what you should do is hit all the forums pertaining to the GK tiburons that have their dynos posted and 1/4 mile times.........thx for your input , but no thx

 

I like how name calling had to come into the discussion. When someone is incapable of logically defending their stance, typically they feel their only remaining option is to call into question some personal trait of the other side that they can attack.

So rather than refute the logic, you refute the messenger. I'm done with this thread and the strawmen attacks it will invariably bring.

 

Um, dude.....if you're referring to the Egghead remark , that's term for book reader not a slanderous name . And if that term bugs you than just take it in the context I said it ya little book reader<there, was that better? > and there's nothing for you to refute.....this is real world experience not note book quotations. You spoke without real on hand experience on this issue(if I'm wrong then by all means speak up) after all this is a forum , that's what we do we get the information out there so that these guys know what to expect. If you feel I'm wrong on any level of this little chat please expound with your rebuttle and I will give you the benefit of the doubt ...I'm not Jesus and I dont walk on water and have definately been off a time or 2 so dont be shy if you think that you have actual useful information that says I'm wrong then by all means I will let everybody on this forum know that < Ooooops , I was wrong > Dont be shy .......speak up :3_winkthu

 

^^^ its called "Ad Hominem." Otherwise known as FLAME.

 

LOL, okay, decent debate thus far.......let's just keep it civil fellas, and it can continue.

 

LOLOL.......the kid reads alot , and he might actually get me with something I'm unaware of . Hey it happens :3_wink: