abdywgn
dismantler
I did that with my 69 340 Dart 4-speed; used the auto recommendations for 13 second range because i was running a 3.23 SG. car went 13.18 at 108 best in 3rd gear thru the traps.
cubic inches vs. head flow vs. rpm
- Thread starter abdywgn
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B3422w5
Well-Known Member
Some of us are good at other things other people cant or wont do. Its good that you can port heads and assemble your own engines.
You probably shouldnt demean others who cant, or may not have the time or inclination to do so.
I like to think my combination of smarts and hard work have combined to put me in a position to where my ideas can be made into reality by porters and assemblers. They do it every day for a living. I dont mind paying( and can pay) for that service.
Many people cant do what i do. I dont hold that against them.
Pretty silly statement you made John.
I don’t hold it against them but trying to encourage them not to be helpless or afraid to learn. Sorry if I offended you or others. I’ll bow out now
abdywgn
dismantler
so I'm 60 but I found it easier doing swap meets and meeting people face-to-face. working in auto part store and dealerships had it's benefits of connections also. yes, internet has made it easier to buy parts, get ideas but alot is missed by not standing around in the garage bs'ing and throwing ideas around. I still have my Craftsman socket set my dad bought as a Christmas gift the first time he was in the hospital over Christmas.
B3422w5
Well-Known Member
Like many, i have become “ dangerous” over the years, but i have found trusting people who know what they are doing is worth its weight in gold. I do what i can, and dont do what i cant
yellow rose
Overnight Sensation
To be fair, I don't think that's what 'pittsburgracer' is saying at all. But I also share his perspective. not wrong, just different.
Translation: If I didn't learn how to be self-proficient, I could not afford to do this race stuff, or *****. You fill in the blank..
A little mutual respect heals a lot of wounds..
B3422w5
Well-Known Member
He has said very similar things on other forums.
I respect his knowledge, but unlike him retired at 60 and lots of spare time, i work 7 days a week at 62 and have little/ zero interest in putting motors together with the limited time i have.
Its good he has that skill, others have other skills. Its all good
Duane
Well-Known Member
No need to bow out. I agree with many of the wise statements made by you and the others.
My 41 years tinkering with cars and engines is very much like yours.
I agree that to learn you have to be willing to try yourself. But it also helps to have good teachers. I rebuild my first engine in grade 9 auto shop. It ran successfully. But only had a $100 bucks in parts.
My first trans rebuild did not work.
That is how you learn sometimes. I am still trying to learn any way I can. I never understand why some people get bent out of shape when something is quoted from a book. Those books are written for people who are willing to learn. I do,not have your amount of years racing but have been around it for many years. I have seen many people get out of it because they pay top dollar for everything because they are afraid to try and eventually the cost becomes prohibitive and they leave the hobby.
But somethings I will pay for because those areas I do not have enough experience in. Paid a guy last winter for a full cage and such.
Was not cheap but I have no regrets because it was done right.
Ok. Thank you for the clarification. It can be hard to cut through all the noise sometimes.
I must say, it's kind of hilarious I understand both of your perspectives. I was always too broke and short on time to have total success but, I really clung on to the victories, no matter how small, I had.
I've been porting heads, on an off, for nearly 30 yrs. Mainly cause I'm fascinated with it, AND I can't afford to pay someone else to do it. Having my own flowbench has made that quest a very humbling experience, and was also an education that can hardly be bought.
Not to take anything from you, of coarse.. Kudo's in fact, that you STILL find time for your passions. (remarkable, really. 7 days a wk?) I stand corrected
BTW: I was forced into retirement.. head on collision can do that..
B3422w5
Well-Known Member
Ok. Thank you for the clarification. It can be hard to cut through all the noise sometimes.
I must say, it's kind of hilarious I understand both of your perspectives. I was always too broke and short on time to have total success but, I really clung on to the victories, no matter how small, I had.
I've been porting heads, on an off, for nearly 30 yrs. Mainly cause I'm fascinated with it, AND I can't afford to pay someone else to do it. Having my own flowbench has made that quest a very humbling experience, and was also an education that can hardly be bought.
Not to take anything from you, of coarse.. Kudo's in fact, that you STILL find time for your passions. (remarkable, really. 7 days a wk?) I stand corrected
BTW: I was forced into retirement.. head on collision can do that..
Haha... good deal bud. Sorry about the accident.
Yea, i own a car dealership. Open 6 days a week. Most Sundays i drive from here in Michigan out East( 8.5 hours) where i have a long standing trusted source to buy used cars.
I buy on Monday, drive the 8.5 hours back on Tuesday, work in the store Wednesday through Saturday, and start it all over again.
I take January off, and a few select weekends in the summer to race, etc. and sometimes scoot out on a Saturday for a local bracket race. But 40+ weeks a year the above is my schedule
Trying to get retired here in the next 3-4 years
Yeah.... always wear your seat belt..
You're in a nice area there. I bet it feels good to get out of the 'thumb', and back into the quietness of Portage.. I have an uncle, by marriage, that lives there. Being 40 minutes from Martin probably keeps your racing spirits high too ! You're lucky, nice track.
B3422w5
Well-Known Member
Thanks. Never lived in the thumb. Went to high school here, and after time in the military and brief time in Texas have been in this area. Used to troubleshoot mainframe computer systems, till about 29 years ago. Now car business. Was a big career change
Yes, 131 is a great track and its nice its close by. I used to index race up at Stanton( Mid Mi Motorplex) but havent been up there in a long time now.
Just 131 and a yearly trip to Norwalk for the most part
Yep, drive about 50k miles a year, been lucky, never had an accident.
My little bro has a 66 Dart Gt with a 416 he races
abdywgn
dismantler
had 002 & 003 springs with long shocks and pinion snubber, front had 6 cyl. t-bars with used shocks. it did not spin but 27" dia. slicks were not ideal, 25.5-26" would have been great but $100 bought me the 27 inchers mounted and ready to go. I will probably make the same "mistake" again on this car because later on I'd like to toss in a 3.73 gear, so that is what the engine will be built for. just like the other had pieces intended for the auto combination. that and I still have that 3.23 SG pumpkin.
The only substitute for cubic inches is cubic dollars.Basic rule Cylinder head flow in cfm X2 will be your HP there are variables as always,but this will ball park you.Ie I have a ported set of Magnum's that Flowed [email protected] 225 X2=450HP.Hope this helps
The problem with the 2hp per cfm rule of thumb, pretty sure thats more inline with big cam and cr race engines. A 285 and 10:1 probably gonna be more like 1.8hp per cfm
And obviously less cam and cr will be less.
dart_68
Well-Known Member
Something I've not seen mentioned is the bore vs stroke combination when it comes to how fast the air is moved.
What I'm talking about if is you take 2 engines with the same CID but one is big bore and short stroke and the other is small bore and long stroke, the big bore engine will move more air vs. crank motion. In other words, a big bore engine will move more air per, say, 1 inch of crank stroke than a small bore engine thus requiring a larger port.
This thought came to me when I was looking at a set of Pro Stock heads and pondering the huge port sizes.
What I'm talking about if is you take 2 engines with the same CID but one is big bore and short stroke and the other is small bore and long stroke, the big bore engine will move more air vs. crank motion. In other words, a big bore engine will move more air per, say, 1 inch of crank stroke than a small bore engine thus requiring a larger port.
This thought came to me when I was looking at a set of Pro Stock heads and pondering the huge port sizes.
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Say 408 big vs small block, at the same rpm, amount of time the big block moved on inch wouldn't the small block move more than a inch since its got a longer stroke needed the same amount of air ??
The small engine moves the usable rpm higher for a given head/port flow, and the larger engine will be top out at a lower rpm. It is only one variable in a very large set of variables.
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