How Much Can Heads Improve Compression???

-
moparmat2000 said:
My God this thread is old. I posted to it in 2015. I really stalled out on my build. Ended up buying a 4" stroker crank from ohio crankshaft about a month ago though. Bought some new eagle H beam rods, and a clean used set of KB forged stroker pistons off fabo these are a street engine stroker piston. With a .040" headgasket should put me right at 9.8-1 cant remember the PN of em. This will let me run the 91 octane thats in my area.
Click to expand...
If you are in the Grand Teton area, you are probably at 5-6,000 ft or more. No need to worry so much over CR. The lower air pressure will take care of it, once the fuel-air mix is set right. (now driving to a lower altitude WOULD be an issue...., both due to the air pressure increase and the carb not responding to that.)
 
rumblefish360 said:
Wow! Old thread.
Click to expand...

There's another thread on the old closed chamber small block heads that I had to refer to this one for some pictures... So I updated this one as the old format it was made with did not let the pictures come up...

moparmat2000 said:
My God this thread is old. I posted to it in 2015. I really stalled out on my build. Ended up buying a 4" stroker crank from ohio crankshaft about a month ago though. Bought some new eagle H beam rods, and a clean used set of KB forged stroker pistons off fabo these are a street engine stroker piston. With a .040" headgasket should put me right at 9.8-1 cant remember the PN of em. This will let me run the 91 octane thats in my area.

So yeah dealing with what i deal with on a daily basis, i am pretty much outta G.A.S. (Give A ****)
Click to expand...


This build got delayed a bit also... I'm now having to mill the intake to fit the engine... As soon as that's done, I have decided to put it in our Valiant wagon as the kid sold his Challenger that we were going to put this into...
 
hehehehe
Time marches on
nothing stays the same.
I would rather have lotsa-compression and a stock cam, than a factory 340 cam and pressure in the basement. Nothing wrong with a 318 cam that a nice set of valve springs, a 2800TC,a freeflowing exhaust, and 4.30s won't cure. Just cuz it makes peak power at 4500 to 4800, doesn't mean they can't rev to 5500 and beyond. 4.30s are nice cuz you can hit 60mph at 4800 at the top of second gear, just after the factory cam peaks. Two gears to 60,me likey.The 2800 will let the engine launch close to peak torque, and the tires even at the stock compression ratio, are gonna be begging for mercy.
The stock 318 torque at 2800 might be as much as 300ftlbs, so 300x2.45x4.30=3160ftlbs, multiply that by at least 1.2 for the TC hit at zero mph, and you have 3800ftlbs available to roast tires with. Heck you could leave the big-valve heads on and a big two barrel and still burn rubber.
But even if the torque is only 200ftlbs, the math still says 2500 tire-frying ftlbs at zero mph.
I'd rather have the hi-compression for a cruiser because it will get better fuel-mileage, and the low-rpm transition response will be much improved. At higher rpms lower compression doesn't hurt that much, but at low rpm lack of cylinder pressure takes all the fun out of a combo.
As long as it doesn't detonate. Cuz that can quickly ruin a good time. And if you have to burn best gas all the time, well then you trade off efficiency for dollars and end up at the same cost per evening of fun, so sometimes more is not better.
 
nm9stheham said:
If you are in the Grand Teton area, you are probably at 5-6,000 ft or more. No need to worry so much over CR. The lower air pressure will take care of it, once the fuel-air mix is set right. (now driving to a lower altitude WOULD be an issue...., both due to the air pressure increase and the carb not responding to that.)
Click to expand...
Nope not in Idaho or Wyoming area. Texas flatlands. Went to Idaho Falls, want to go back to visit some day..
 
Just cuz it makes peak power at 4500 to 4800, doesn't mean they can't rev to 5500 and beyond.
Click to expand...
Because it is Generally a stupid idea.
Pushing the revs past peak should be done at the finish line stripe only unless your being chased at your life’s peril or trying to save someone else’s life.
 
moparmat2000 said:
My God this thread is old. I posted to it in 2015. I really stalled out on my build. Ended up buying a 4" stroker crank from ohio crankshaft about a month ago though. Bought some new eagle H beam rods, and a clean used set of KB forged stroker pistons off fabo these are a street engine stroker piston. With a .040" headgasket should put me right at 9.8-1 cant remember the PN of em. This will let me run the 91 octane thats in my area.

Dad sold his express, moved into a smaller house, bought a model A coupe, and is tinkering with that lately.

Problem i have lately last 5 years is dealing with a kid that has mental health issues. This **** cropped up when she turned 8 years old, My household is insane, i end up buying **** for projects and then nothing gets done, because every day there is a ******* emergency around here. Block may finally go to machine shop next week along with other stuff needed to balance the crank and bore it out. Honestly i will probably get it all back, gun brush out the oiling holes, coat it with oil and wrap it in a trash bag, and it will probably sit for another 5 years.

In 5 years she turns 18. I told my wife, at that time, this kid will find another place to live on her 18th birthday because we are no longer legally responsible. And i want her to take her nutty **** and go the **** away. Wife takes her to a head shrinker weekly, kids on meds, wife even had me go to visit w this kids head shrinker for a bit to i am guessing try to deal with this ****, i went a few visits and i finally said to the shrink, no there aint anything about me that needs fixin. Never went back.

My wife went out for a girls night out with one of her friends this last saturday night. Kid had a **** and fell in it over that. Other daughter was at a friends house overnight, my son was already asleep, so i went to bed, told my wife go out have a good time with your friends. If this kid wants to argue, she can argue with herself. Wife says things will get easier once she starts bleedin every month, i shook my head and said ummm i dont think so.

So yeah dealing with what i deal with on a daily basis, i am pretty much outta G.A.S. (Give A ****)
Click to expand...
God bless ya Matt. Best of luck with your build.
 
moparmat2000 said:
Nope not in Idaho or Wyoming area. Texas flatlands. Went to Idaho Falls, want to go back to visit some day..
Click to expand...
Ah OK LOL.... your listed 'location' is a wish, not the actuality. Understood....looking seriously to move out to that area myself.
 
rumblefish360 said:
Because it is Generally a stupid idea.
Pushing the revs past peak should be done at the finish line stripe only unless your being chased at your life’s peril or trying to save someone else’s life.
Click to expand...
Or if you have a too narrow RPM band and have to rev it to get past a too-large gear step with a manual trans.....BTDT.
 
True-ish. Running/racing an odd ball wacky gear spread trans is a personal call and obviously nit the best for the track or constantly running it like it is on the track in the street.

Professing this as OK is just simply bad advice and stupid.
 
Now I hear Rumblefish blathering on about How I am stupid for not shifting at the power peak or a little after.
Enclosed please find a dyno curve similar to mine.
So let's say I do it
Rumble's way and shift at 5900, which I imagine will be 430hp. Now imagine I have a TF and the 1-2 split is 59%, so the Rs drop to .59x5900=3480.... and there we have 250 hp. So the simple average power put down will be; (430+437+250)/3=372
Now my way, I'm gonna run it up to 6400@414hp, drop to .59x6400=3776, and now I have 275 hp there. So the simple average is (415+437+275)/3=376; So I lost 15hp after the power peak, but I gained 25 at the bottom. That's like a full cam size down there, maybe more.
But wait, my way is better for another reason; look at the shape of the torque curve. Look at the pivot point at about 3900. From that point and lower, the torque falls off faster, so I want to be above 3900 to take advantage of the meatier curve, and build a higher average power.
But I don't have a TF, I have a manual trans with splits of .78-.80-.78.. So if I shift the 1-2 at 6300@412hp, and drop to .78x6300=4914, where the power is 400hp, my simple average will be (412+437+400)/3=416. Yikes! This is nearly11% more than the 376 and nearly 12% better than the Rumble-Way
And if I shift the 2-3 at 6100@430hp, dropping to 4880@410hp, With the .80split my simple average will be (430+437+410)/3=426......
That shift happens a 72mph, and I am heading to 93@6100.....into the wind at full-power. I think this is why my little 367 goes 93 in the 1/8; it's up on the cam, almost the whole way. You can see it is putting power down, like it had a cam more than 2 sizes bigger. Thank you GearVendor.
But I could just as easy go to 6300@412hp, and drop in at 5040@420hp, for a simple average of (412+437+420)/3=423.......
Your results may vary,lol.
To be fair
I agree that if your powercurve drops like a stone after the peak, then you would do yourself a dis-service to spend more time there than you need to. I always talk streeters, that's all I know. With a TF you gotta carry the revs, or go to the basement, so if you put a combo together that doesn't carry the power but falls like a stone after the peak, well, dig out the sundial.
As for me and my stock-cammed 318,I'm holding her in second "til she hits 60 or blows up.
I'm a lil like Willrun, I screw my junk together and watch it run. Bolt on an 850TQ, on a small-port intake, on an otherwise stock lo-C 318, with TTIs and twin full-length 3" pipes, ,a 2800TC,with 4.10/4.30s, and watch her fly! Find something to hang onto passenger.......


land_dyno.jpg

Chart pirated from Hughes Engines
 
Last edited:
AJ/FormS said:
Now I hear Rumblefish blathering on about How I am stupid for not shifting at the power peak or a little after.
Click to expand...
A little after peak is good, not the amount you love to write about.
But fear not! I'll prove you stupid in the next paragraph, hold on !!

So let's say I do it
Rumble's way
Click to expand...

Wait a minute here. You are now a LIAR due to the "My way" you say I said in which I didn't in anyway shape or form.

You are purposely misleading everyone and disrespecting myself and them. OK, your don't give a **** about me, so it is now OK? And to everyone else is just fine then?


But I don't have a TF, I have a manual trans with splits of .78-.80-.78.. / Thank you GearVendor.
Click to expand...

And there is the problem running not only the MP O.D. Trans but the addition of the GV/OD. That you thoughtlessly add into the equation where others do not have this option.

To be fair, I agree that if your powercurve drops like a stone after the peak, then you would do yourself a dis-service to spend more time there than you need to.
Click to expand...
Now he agrees with me ....

I GUESS ALL YOUR TIME IN THE CALULATORS IS FOR NOUGHT! LMAO!!!!!!

Don't cry AJ! I'm still not beating you up as you so often pine about.
Your advice (Kind of..... ) fits everyone with a Chrysler manual overdrive trans hooked to a Gear Vendors Overdrive!
And you keep on reving to 7K plus now!

OH! Next time, please print your own graph and not one from hhughes engines. Thanks!

Would those people please stand up and show us all a picture of your 833OD trans hooked to a GV/OD?
 
rumblefish360 said:
Because it is Generally a stupid idea.
Pushing the revs past peak should be done at the finish line stripe only unless your being chased at your life’s peril or trying to save someone else’s life.
Click to expand...
I blew my OD transmission up by 2004 or so. That was a long time ago.
I don't normally use the GV for splitting, just when I'm showing off.
The GV ratios were added after I did the math on the TFs.
I tell you what you short shift if you like, I'm good with that.
And you can scream at me, and call me names, if you feel the need.
As for me I will continue to have fun. I like what my car does when I let her stretch her wings. I like that she goes 7000 without falling on her face. I like that she does this with a little 230 cam. I like that she spins 292s or 325s to 60mph, be it at 5500 or 7000. I choose 7000 cuz it revs me up. The screaming pipes excite me the howling tires get my heart pounding. The smell of burning rubber is fueling the fire. I like it.
My posts are long because I include the reasoning behind them. If you find them too long and don't bother to read to the end, how is that my fault.
Is it my fault you don't like the word blathering? Ok. maybe that was too strong a word. Forgive me, please.
As for the graph, I said I pirated it. I said the engine was similar to mine. and it was used in ALL the calculations. So where's the problem?
Look I know you are not a stupid man. I would never call you stupid nor infer it by saying that you say stupid things. You say some things that I don't agree with, but I just move on, no need to plaster your posts with big red eXes. Cuz maybe some day my opinion will change, and then all the big red eXes would be to my shame.
Look
I'm sorry if blathering rubbed you the wrong way.
I'm sorry if you're having a bad day.
I'm sorry if you don't agree with me.
I'm sorry about a lotta things.
But I'm not sorry that I didn't fly off the handle when you inferred I was stupid, called me stupid, called me a liar, and yelled at me.
I have enough love in me for both of us.
 
You must log in or register to reply here.
-

Back
Top