Chevy 307 engine

Do you have any idea what you just said sir?   SBC is not just a 350. You make it sound like it is. I never dissed SBC in general.  Yes he is hardcore and as such he has is own opinion.  SBC is a good motor and I never said anything about it being bad.  If you share my view of reading means learning, then perhaps you should read some more. SBC is 283 - 400.  Not just 350.  

Also, when I say 305, 350, and 400's are common, look at the vehicles GM has made. Almost every vehicle from 1970 has a 350 standard and 76 for the 305. Cars, trucks, Vans, SUV's. Almost all Vortec p/u are either 305 or 350.  I am not talking about anything other than a V8.  Ford for example, they are mostly 302's and 351's. 

Read the start of the post. Everyone told him to remove the 307 and replace it with a 350.  Not asking what he wanted to do with it. My point was and is, build it up. See how you like it. You can always put those parts in a 350.  SBC is SBC 283-400.

No you are correct in what you see JCharlie. Unfortunately, CompCams does not list .050 lift specs on their website for this cam.  So I have no idea what they are.  Jeg's I believe does, but they don't say and I wanted to have specific IVO, EVO, IVC,EVC timings.  If you have or know a place to get the .050 specs, I'd be happy to re-run the dyno.  

I want to make a general statement about dyno sim software. This is not directed at you Jcharlie but rather anyone who is reading these posts.

I do not think these dyno sims are 100% accurate and I have never claimed them to be.  I think they are helpful for people like me who do not have access to a dyno facility.  I do believe there is room for error, and I think the figures, while perhaps close in some or most results, are probably more of a ballpark-perfect-world figure.  There are many things I would like to see this software factor in.  Obviously, a performer RPM DP or Airgap manifold will help an engine perform better than the GM intake.  However the software does not care.  I think that diminishes the results some.  Also altitude is not factored in, octane, weither the gas has ethonal, what kind of sparkplugs you have, ignition, carb type/brand...etc....

The only thing I have to compare these results to realworld is a comparison Horsepower TV did a couple weeks ago when installing a new cam. They used this software to determine the cam they would use and they said the results were close.  I would like to see people who do have engine dyno's compare the results because I am curious.

Just trying to help people out and get some feedback and help in the process...

I would like to hear feedback on peoples experience with this software and if they were able to compare the two, instead of this constant dissing of it.  It's always bashed, but no one says why....

Re the XE250H cam, I found the following in a Comp Cam catalog:

--  Duration @ 0.050": Intake 206, Exhaust 212

--  Adv. Duration: Intake 250, Exhaust 260

--  Lift (w/ 1.5 rocker): Intake 0.432", Exhaust 0.444"

--  LSA: 110

--  Operating range: 600 - 4,600rpm

The catalog didn't provide any valve timing specs.

I will go ahead and do another dyno with the specs you gave, however to input the data I have to create a cam profile with ivo/evo timing that the software generates based on the duration, center angle, and lift. So if the timings are not exact it may be off, but It may be close.  Thanks for the info. Wish they would post it on the internet.  

here's the xe250h cam in action.   

307 - 3.875" Bore / 3.25" Stroke

9.09 CR  -1.7IV / 1.5EV 70CC Head Stock porting / low performance

Xtreme E-Cam 250H-10 @.050 .432"/.444" - 206/212

RPM        HP       TQ             Vol. Eff%

2000     127      332              75.0

3000     193      337              78.8

4000     255      335              83.4

4500     275      321              83.7

5000     279      293              81.1

5500     269      257              76.8

.050 specs move the power range up the rpm scale opposed to adv. dur.

For fun, here is the results with a 350 block and 882 76CC heads, same XE250 cam @0.050 ... 9.10 CR 1.94IV 1.5EV

rpm        hp           tq

2000      148         389

3000      225         394

4000      299         392

5000      338         355

6000      315         275

Hey I run a 307 and dont call others punks.  There are some good and bad points to all engine combos 305 heads can work well if your not running a 671 or 871 as the piston cost goes way up as for the die hard 350 guy if you want to talk no budget look at the 307 that took second in last years small block challenge from phr that thing was wild and a true street engine where the winner was not and that was admitted buy the builder.  For the guy looking for better pistons look up weisco online they make them and actually will make any sized slug you need but borrow a big pocket book first long before their entrnce into the racing market for cars they developed a solid audience in the Harley market.  On the RPM intake it workes well although if you have a larger cam or switched rockers and want a little more HP look to old tech prior to getting mine I ran a GM aluminum 5" from the 60's and the center of the plentum was ground down about two cm it ran quite well in the top end great thought for drags although it gives up some low rpm power I would ask an air flow professional that actually does manifold modification often before cutting up one your self they would probbably just recomend letting a machinest port match them though.  I noticed a little gain not much from operating on my rpm so ask a pro I just like to race I appologise to all for the fact that I am horrible at spelling.

from phr that thing was wild and a true street engine where the winner was not and that was admitted buy the builder

I don't understand that part. 

anyone that believes a 307 is or can be stronger running than a 350. deserves the general motors A$$CLOWN award. the only thing that beats cubic inches is cubic dollars.building a 307 is like running a fartcan muffler on your ricer.they do nothing to make your car go faster. and if you believe that a computer sim is accurate you deserve the I.B.M. A$$CLOWN award. if G.M. ever made a lemon it was the 307. a 283 bore and 327 stroke. why not just get a 327.anyone that has an I.Q. and knows anything about chevies. will tell you the 307 sucks. ford had the edsel. and chevy had the 307. the bores are to small to ever breathe. the 305 has a 265 bore and a 350 stroke.and it has the same problem.everyone on this message board is trying to be nice to you. but me. when someone tells me the world is flat. i tell them you are so full of it your eyes are brown. so mister 307 what color are your eyes?  

The winner of the contest started with a 350 block and built an awesome engine although the follow up issue or the one after that when they printed all of the enterviews he stated that with the rings he used and some other parts it was not a streetable engine.  Switch the rings and it would still be massive.  I am not at all putting down the 350 in reference to the post after yours I am just saying to those bagging on the 307 there is a lot more potential than they are giving it credit for.  Plenty of people pick them up to swipe the crank and make large jornal 327's some of the blocks can easily be bored that far.  I know it's not the coveted dz302 but there is no reason to bag on any thing made in the good ol USA that can be a wonderfull platform for development.   

The winner of the contest started with a 350 block and built an awesome engine although the follow up issue or the one after that when they printed all of the enterviews he stated that with the rings he used and some other parts it was not a streetable engine.

Joe Sherman is the guy who won, if you ever get a chance to meet him he is a very interesting guy. He worked for Edelbrock a long time ago, he is credited for inventing the 383 SBC, he use to run 365 strokers before that. Him and his sons had a street drive, not streetable, 66 Nova Wgn that ran in the 9's on 9' slicks. I have seen his not so streetable motors driven on the street. A friend of mine has one of Shermans motors in his car- all aluminum 440 SBC runs low nines and drive it on the street but it is not very streetable.  

I would love to meet Joe Sherman and I am in no way attempting to discredit him.  604.1 peak hp & 528 Tq is awesome, If only I had the budget to get one of those built for myselfe and built with strickt rules reguarding products modifications etc..  I was simply stating that the 307 based entry by John Beck was amaizing with 556.3 Hp and 518 'lbs of Tq.  Simply put a 307 has potential and should not be doged true there is no replacement for displacement, unfortunatly factories do not give us this quality and efficiancy, wich is why hot rod did that whole europe vs japan vs america thing.  It's a 5.0 Liter with many of the same factory clearances as a 350.  Save the rod bearing oil clearance wich is only .0001'' different, the interference fit in rod wich is .0001 to .0008 with the 307 and .0008 to .0016 with the 350 The Ring clearenc in the grove tolerances are just flipped from top to second and vice versa, and of course the ring end gap .01to .20" for the 307 and .013 to .023 top .013 to .025 second for a 350.  If it had a 283 crank and a 327 bore people would praise the almighty 302 yet the 307 seems to be getting knocked hard in here when it has good potential as a power plant especially with its wonderfull capability to wind up quickly.  Compared to a 305 instead of a 350 many of the statements against the 307 would likely praise it as a platform once you get the copression up some decent headers a good intake and carb combo its still a sbc.  

IMO:

I agree, John Beck's motor was very impressive. He thought outside the box. It was a contest and it showes how attention to detail worked out, but at the same time it showed the differance in power between going exotic and going basic which more poeple would afford to do. So what I am saying is that it made you look at the fact, is it worth those exrta dollars for that extra hp-in a contest, yes. Or save some money and using what you have and know it still capable of making great hp. I also agree that a 307 is still a SBC and can make good power.

Joe Sherman 604.1 peak hp & 528 Tq

John Beck 556.3 Hp and 518 'lbs of Tq