which motor would make more power

[motorsci]

Me and my buddy have the same set up. n42, flatops, su carbs, sm needles crane high6 ignition with ps2 coil and n36 intake. The difference is he has a schneider stage 3 cam 270/280 duration 460 lift and my cam is a stage 2 274/274 480 lift. both are cars will be on the road in the spring a local z club has a dyno day and are z club is planing an event at the drag strip on test and tune night we plan to post are numbers but juist interested in what you guys think might have the most power

[thehelix112]

Are you quoting intake/exhaust or exhaust/intake timing there? Can you quote in 0.05" dur because adv dur means jack. Same exhausts?

 

Dave

[motorsci]

The stage 2 duration is 234 intake 234 exhaust

The stage 3 duration is 232 intake 234 exhaust

[Guest bastaad525]

LOL talk about splitting hairs. It's gonna be real close either way. If I were a bettin' man, I'd go with the 274/274, 480 making like... 5 more hp if that LOL Don't put any money on it though, and don't lose any sleep over it either

 

And don't be surprised when you get whupped on by a new Civic or something like that... hate to put it to you that way, but I went the EXACT same route you did in my '72 240, overbored 2.8L engine (.060 over, technically 2.9), flat top pistons, N42 head, minor port work, 480 lift 270 duration cam, rebuilt SU's with SM's, 6-3-2 headers from motorsport, full 2.5" exhaust....

 

Netted me ~170 rwhp and about the same torque, and a high 14 second 1/4 mile, 0-60 in about 6.5 seconds. Felt fast, sounded fast, but hardly 'fast' by todays standards, with even some of the lowest priced of the entry level sport compacts being about that quick. Just be careful who you run against

 

I got tired of getting whupped on and ended up dumping the whole setup (engine cost me about $2500 to build, I was only able to get $600 for it) and going with an L28 turbo.

[Guest norm[T12SDSUD]]

HHmm or you could end up running 13.4 @ 101 mph, which is what I did with my old stock block 2.8L with shaved N42 head and 9.6:1 CR with stock SU's and small 272/282 .460" lift cam and crappy Nitto drag radials.

Drive it like you ain't afraid of towing it home and you just might be surprised what she can do!!

 

Later,Norm

[2802NR]

bastaad is right. I'm running a .030 over flat top n42 with the stage III 270/280 .460 lift. 3 into 2 header, 2.5 exhaust. On stock FI, I put 169hp and 175ft/lbs tq at 4200ft elevation. needless to say I expected a little more but thats the way it goes sometimes. Anyway, I would bet the two cams will produce different torque curves with very similar max numbers. just my 2 cents.

[Guest norm[T12SDSUD]]

Hey 280NR, at sea level that 169 HP would have been 190 HP!!

 

You lose 3% of your HP for every 1000 ft of elevation increase.

 

Check out this ET correction website for altitude.

 

http://www.smokemup.com/auto_math/nhra_correction_factors.php

 

Later,Norm

[Silent]

hmm according the calculator, i ran a 13.80@99

 

hmmmm

stock head

stock su's

wheeeeeeeeeeeeeeeeee

[johnc]

Me and my buddy have the same set up. n42, flatops, su carbs, sm needles crane high6 ignition with ps2 coil and n36 intake. The difference is he has a schneider stage 3 cam 270/280 duration 460 lift and my cam is a stage 2 274/274 480 lift. both are cars will be on the road in the spring a local z club has a dyno day and are z club is planing an event at the drag strip on test and tune night we plan to post are numbers but juist interested in what you guys think might have the most power

 

The one that is has been more accurately measured, cleaned, machined, and assembled. The one that the owner spent more time on making sure all the parts matched up properly. The one that the owner assembled, checked, disassembled, adjusted, assembled, checked, disassembled, fixed, assembled, etc. The one where the owner spent 8 hours getting the cam timing exactly right. The one where the owner spent 4 hours adjusting the valves. The one where the owner spent 1 hour properly breaking in the cam on startup.

 

Basically, the engine that the owner cared more about and spent the time to do it right instead of just throwing parts.

 

BTW... doing it right can get you 208hp at the crank on a 2.4L engine using the stock cam, valves, pistons, rods, crank, untouched head, SUs, etc.

[BRAAP]

Me and my buddy have the same set up. n42, flatops, su carbs, sm needles crane high6 ignition with ps2 coil and n36 intake. ..... just interested in what you guys think might have the most power

 

 

The engine that makes the MOST torque at the highest RPM WINS!!!!

 

That's my $.02

[Guest bastaad525]

bastaad is right. I'm running a .030 over flat top n42 with the stage III 270/280 .460 lift. 3 into 2 header, 2.5 exhaust. On stock FI, I put 169hp and 175ft/lbs tq at 4200ft elevation. needless to say I expected a little more but thats the way it goes sometimes. Anyway, I would bet the two cams will produce different torque curves with very similar max numbers. just my 2 cents.

 

Come to think of it, when I dynoed that 171 rwhp I was at high elevation as well... I was actually very close to LACR which is at like 3000 feet or very close to it. This was in the Palmdale/Lancaster area. So that might have been a few more ponies down near sea level.

 

Norm, many people are still left wondering how you, and only you, seem to be able to run as fast as you do on that setup. The closest I've seen to your numbers has come from Bryan Little who has also done a very similiar setup and ran I believe a 13.9? I know you've done a lot of little things (and some big things, like some very nice headwork if I remember right, and we all know L6's make all their power in the head) that all add up, but somehow people who do many or all of those things still never get the numbers you have. I still think you've got some secret things you've done that you don't tell everyone

 

Truth is though that on average, a flat top piston, N42 head combo (~10:1 compression) with stock SU's and SM needles, a mild cam, and header and freeflow exhaust, in a 240 chassis, is usually gonna be somewhere in the 14 sec range or maybe high 13's if you're a really good driver and have great tires. Add headwork (porting/polishing) bigger cam, maybe tripple carbs, or consider a lighter early 240z (70-71, like Norm has), some combination of these things or all of the above, and you're pretty much guaranteed 13's. Getting to 12's seems to require boring and/or stroking to increase displacement.

 

By the way, for what it's worth, I found when I dynoed before and after upgrading the cam that the torque peak number barely changed at all, like 2-3 lb ft, but peaked at a different rpm and hence, ended up making more hp. That was from the stock cam to a 480 lift 270 duration. Before the cam was 150 hp / 170 ftlbs, after was 170/170. Torque peaked about 800rpm later in the powerband if I remember correctly. Of course, there may have been variation for weather or whatever so I won't claim outright that the cam was worth 20hp. At any rate, I don't see there being any significant difference between the two cams he listed, though I would be the one with the great lift would make a tad more power if either of them did.

[JMortensen]

I think Norm gets some 10ths and some mph just for beating the crap out of his car. Most guys won't thrash their precious car like he always says he does. That WILL make a difference. Shifting as though you don't need to drive the car home later makes a difference. Launching like halfshafts never break makes a difference.

 

Another thing that I think is CONSISTENTLY lacking in L series builds is the cam. I think the Z community would all be better off if MSA renamed the "Stage III" cam the "Stage I" and had Schneider make some more larger cams. I know they don't because the bigger cams don't work with FI and they don't want pissed off customers (plus it probably gives the FI guys the feeling like their cam doesn't suck ***), but the camshaft is a big deal. Bastaad you always say that the L makes more power with the head, but I'm getting a little tired of seeing "built" L series with that .460/270 camshaft. As BRAAP says, more torque higher means more hp. That means a bigger camshaft than that PUNY Stage III. IMO.

[johnc]

Cam braggadocio: "If you ain't duratin' at 300, you ain't s**t!"

[JMortensen]

Cam braggadocio: "If you ain't duratin' at 300, you ain't s**t!"

That means I ain't ****, but it's also a true statement. I got sucked into the weenie cam just like everyone else... When I bought my .490/280, I heard: "You won't be able to drive it on the street", "It won't idle", "It will be impossible to drive in traffic". BS!!!

[thehelix112]

I must admit I don't get the fuss either. A couple of my mates have 76 works cams in their L20Bs and with the right tuning (silly webber people) they will idle at 800rpm quite happily. Thats from a what? 230 0.05 dur cam or there abouts?

 

Go big.

 

Dave

[Guest norm[T12SDSUD]]

Hey Bastaad, as far as I know I have shared 95% of my "secrets". The other itty bitty tiny 5% secret stuff shouldn't add but a few HP at most.

I think the key really is in driving the crap out of my car!

 

You all know how much stuff I have broken in the past, but then again it is not uncomon for me to run 20-30 times in one night. I actually ran 44 times before breaking the 1-2 shift dog on one very slow night.

 

I let off the gas when I shift and I don't launch at more than 3500 on the street tires.I do however always do long burnouts on my regular street tires that, contray to popular wisdom, WILL indeed lower your ET at least a tenth or two.

 

I can't believe my headwork is any better than anyone else cause I didn't even know what I was doing. I just simply made the port holes about a 1/16"-1/8" larger on the intake side.

I highly polished my pistons and combustion chambers which according to HOT ROD magazine can add quite a bit of HP. If I remember the article correctly it said you could gain 5% or more just from that step.

 

Anyway, I wish more people could duplicate my times as I know it can't be that hard to do!!

 

Later,Norm

[Guest bastaad525]

Norm, if those last few secrets of yours only add "a few hp" my question to you is, why aren't you sharing them? No offense but it doesnt' make sense to keep 'a few hp' secret but let everyone in on the big stuff. I also question just how big of a difference your driving style is making. Not saying that driving like you stole it won't make a difference, but again, consider your 'competition'. As I mentioned, fastest I've seen a 240 comparable to yours go has been Bryan Little at 13.9 (not saying there aren't others who've gone faster, just none I know of). Now you're going to tell me that beating the **** out of a car accounts for one full second in the 1/4 mile? I find that hard to believe. Not trying to sound standoffish... just saying, there has to be more to it than just launching hard, banging the gears, and a few hp worth of secrets.

 

 

Jmortensen - When I think in terms of Z I always consider the cam as overall part of the head. I guess what I should say is "Power in an L28 is NOT found in the block"... You can take any L block and make good power on it... 2.8, overbored 2.9, bored and stroked 3.0 +, even the 2.4. The displacement doesn't make all that much difference, yet many people think it makes all the difference. I have found in my personal experience that going with overbored pistons, more displacement and higher compression really didn't make a whole lot of difference in power. My biggest gains came when I swapped the cam, and when I went from a stock, bandaided and barely cutting it EFI to the SU's. And what I've observed from others, the largest gains always seem to come from headwork, and then of course upgrading the cam and carbs/etc. to take advantage of that. Whereas if you upgrade to tripples or a big cam w/o any headwork, never seems to make nearly as much difference.

 

I agree about the cam sizing... the 480/270 was barely a step over stock, in only moved my powerband like 500rpm. The idle was barely any worse. I would imagine there is a ton of room there to put something really nasty. I wish I had known more about cam sizing before I bought my cam because I do feel like I got short changed by the cam I ended up with, I really wanted to move my peak power up to like 6500 and make it a real screamer.

[Guest norm[T12SDSUD]]

Well if my couple little secrets add up to 6-8 extra HP then I will still be a tenth quicker than my nearest SU competitor so I don't want to share!! hehe

 

The last few secrets have to do with the SU carbs. Just little stuff but maybe enough for 6-8 more HP!

 

Also REMEMBER the track I race at is only 330 FT above sea level AND I race with open header which will add 2 tenths and when I ran the 12.8 it was around 50 degrees which adds even more HP!!

 

Later,Norm

[JMortensen]

My biggest gains came when I swapped the cam, and when I went from a stock, bandaided and barely cutting it EFI to the SU's. And what I've observed from others, the largest gains always seem to come from headwork, and then of course upgrading the cam and carbs/etc. to take advantage of that. Whereas if you upgrade to tripples or a big cam w/o any headwork, never seems to make nearly as much difference.

I don't have any personal experience because my head was already very mildly ported and I already had my "big" cam in there when I added triples, but as I've said before it was an INSTANT 40 hp easily. I can't tell you what it would do with a stock cam, but I'd be absolutely shocked if adding 44s or 45s onto a stock head and cam didn't add a sizeable amount of hp. People who have 40's (with only a few exceptions) don't seem to get that big an increase. I've seen that enough that if you offered me a set of 40s for $200 I'd turn you down. But the 44s or 45s are a different story and although as I said I don't have personal experience I'd be really surprised to find out that you were correct on that one.

I agree about the cam sizing... the 480/270 was barely a step over stock, in only moved my powerband like 500rpm. The idle was barely any worse. I would imagine there is a ton of room there to put something really nasty. I wish I had known more about cam sizing before I bought my cam because I do feel like I got short changed by the cam I ended up with, I really wanted to move my peak power up to like 6500 and make it a real screamer.

Well as I said before, I think having the Stage I and Stage II sets it up so that the stock FI people can say "I have a Stage III" and feel like they need to step up to the Magnum condoms. Aside from that there are other issues that come into play like the valve stem seals hitting the retainers and coil bind that need to be dealt with, that I'm sure your average Joe just isn't aware of. So instead of being sold a cam that requires a bunch of additional headwork to install, they keep it simple. It's too bad. I really do wince every time I see a "Check out my new L series" thread and they've got a Stage III from MSA in there.

[Guest bastaad525]

I never tried tripples out for myself but I've had several interesting conversations with guys who've done lots of dyno time and quite a few times I was given evidence that people who throw tripples on a bone stock head and cam often gain no power, as a matter of fact they ended up losing midrange, and even if they picked up some power in the high rpm range the car overall was slower or felt slower. I think the stock intake setup, whether SU's or EFI, doesn't really pose any huge restriction to the stock head and cam.

 

I honestly have a hard time believing tripples added anything like 40 hp unless your head was so worked that it was just choking on whatever you were running before. I've had guys who've dynoed give me numbers and it was always more in the range of 15 to 25hp and this was NEVER on a stock head and cam. I have moved away from the whole 'carb scene' since getting into turbo and EFI so it's been a long time since I've really bothered digging or asking or talking to people about it. But I remember during the year that I built up that motor and finally switched to SU's I did hours and hours of reading, posting, chatting and talking about it. I do know that enough people have dynoed before and after that at the time I had no problems getting some good numbers and in the end I decided based on the info given to me that tripples just weren't worth the extra cost and effort for my relatively mild setup.

 

I know this is really not a scientific bit of evidence but it was a strong influence none the less... the day I met up with an owner who had a nearly identical setup to mine, same year car, same block and head... everything almost exact except his had nicer paint and he had tripple 44's. We agreed to allow each other to test drive each others car... I will skip the long of it and summarize... I felt that his car was a dog until you revved it up high, in normal driving I was very unimpressed with the torque but once the tach hit like 4500rpm then it screamed. His impression of mine... well... his first thing he said to me after driving mine was "I'm switching back to SU's!" I kid you not.

 

I don't doubt that they add power if you have the setup to take advantage of it but just like a big cam they are a tradeoff. But I still have a hard time believing 40hp *shrug*.