Inliners International Forums General Discussion Engines Mid Range Power

Now for some mid range power. I6 230 with stock rebuild. Electronic ignition, split long headers, dual 1bbl carbs atop an Offy intake.

Any suggestions?

Sixpack: I don't know if the 230 is already built or in process or what diff ratio/tires you have/plan on running. You didn't mention if your cam is also stock.

This site has very good info on cam selection and what engine mods/cam will give you mid range power. They all have to work together.
Just remember, you always give up something to get something. http://www.amotion.com/

Thanks El Plymino,
I'll have to sort through the information. I have an uncle who has a 69 Road Runner I bet you'd like. If I had to look at the list of ranges and guess, I'd say I'm only looking for mild street performance. Driven most of the time in city, with an occasional 20 mile trip on the highway. But if a young kid pulls up beside me and eyes me, I would like to have a little power to go with the noise! The engine was already built when I purchased it. I believe it to be stock except for the carburetion, headers and electronic ignition. Not sure I have the ignition correct as it is wired up into my truck by guess. It runs ok, starts beautifully, but just doesn't seem to have much power.

[This message has been edited by SixPac (edited 12-27-2003).]

Long tube headers may not be the best for mid range power, short tube or tri Y(two into one) usually works better.

I believe Tony's right with regards to the headers and how the length affects the torque. I have 36 inch tube headers attached to my 292. Probably losing a bit of low end but the cam more than makes up for it.

I recommend the RV cam for Chevy inline 6s that JC Whitney sells. Works great for me in my 292. My low end (< 2000 rpms) is not as good as my old stock 250 but the mid range torque is superb and HP is greatly improved.

Here's the numbers on my cam>

.464I/.490E lift and 194I/204E duration at .050 Performance-wise those numbers are a little better than stock. I believe the numbers are the same for the 230/250 grinds as well. These cams are produced by Elgin and sold through JCWhitney.

Cost about 80 bucks for the cam. Money well spent in my opinion for extra mid-rpm (2k-4.5k) boost.

-magic mike-

hello....Long tube headers that you y together are VERY good for low end performance-especially 1.5" primaries which all Chevy Inline headers are Except Clifford headers which are 1.5/8".....by using this setup up and a chamber muffler-any muffler except a straight thru design-or a 2" straight-thru,-not ANY bigger-you will have an excellent combination for low end torque...Magic, glad to see you like that cam for performance and price-i thought you would.... remember this, a cam for a 230 will be small for a 292 ,and a cam for a 292 will be big for a 230.....

Lee

[This message has been edited by LeeLites (edited 12-29-2003).]

If you have a chevy2 You have no choice at this time that I am aware of But to buy cliffords headers. 68 on up chevy2s/Novas Other companys have headers and Not all are 1-1/2 tubes I just in stalled a set few Mos ago on a pick up with a 250 And they were Not cliffords pipes and they were 1-5/8 2-1/2 collectors and we Down sized the collector to a 2in. an Duals all the way back to rear axle with thrush mufflers with turn downs. Hope this is a little more food for thought.}[oooooo]

Ps.
An Now about a week ago after the guys has run his truck this way and after seeing My motor and Other members pictures hangging on our shop wall. He Now has ideas of installing a intake & cam sometime next yr. He was very surprized to see/feel what difference just the headers made on that motor. as i laughed just a little I told him He would be alot more surprized after He makes the Intake & cam change. If he realy thinks Them headers made a difference Just wait till you start doing the rest. In His words AND to think I was going to do the vthing.And now I may have me a little more fun and still save on some Gas.
Humm now if i can only get him to Join

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NovaMan/Twisted6/Larry



[This message has been edited by Twisted6 (edited 12-30-2003).]

Lee,long tube headers may increase the lower speed power over stock, but a shorter tube or tri Y will out power either system from my experience. For racing ,a longer tube works for torque, however on a street engine that's not necessarily true.The addition of a exhaust system with a muffler and tail pipe changes everthing.On my modified 261, I use short untuned cast iron Fentons, a 2 into one system, and it outperforms a long tune header system, no problem.For most of our inlines, high speed is only 4500 rpm, most street driving is below 3000 rpm, the long tuned headers have no advantage in this situation from what I see.

hello...interesting and more learning....I will say that ONLY Clifford currently makes 1 5/8" headers for truck applications and universal fit short tube headers...If you have seen a set of 1 5/8" headers that were new, they were NOS(new old stock)- I have confirmed this many times with Dynomax,Hooker,Hedman, Pacesetter and Clifford and only Clifford makes 1 5/8" headers at this time....I have seen, touched and measured all 5 of these....from my research I have also found none of these manufacturers make car headers at this time-please correct me if I am wrong about the car headers.....as far as performance is concerned, Long tube headers allow a larger power/torque pwer range than short tube headers...if your your results are different then thanks for sharing, but as a general rule, the shorter the tube the smaller the power band, the longer the tube the longer the powerband...and yes an exhaust system does change all this,so for best street results you can tune your engine torque/power band by your exhaust system-short tube vs long tube primaries,collector length and size,chambered muffler vs straight thru(chambered mufflers are best for low end torque due to flow restiction at mid and upper rpm's and small diameter pipe straight thru mufflers are generally good for BOTH low end/mid torque and upper power-NO flow restriction)...of course we all have different opinions-mine are based on at least 15 different exhaust combo's(header design,primary pipe size,collector pipe size and length,muffler desigh-both chambered,straight thru and glasspacks, length of exhaust sytem, dual or "Y" together, where the dual ends, where the "Y" starts and ends)-what I state here is my experince in having a daily driver Inline 6 for over 20 years-if this helps Great!!!On my current 292 I have had 5 different combo's...one thing to also consider in all this is that there seems to be VERY little info on what sound waves do to engine performance-just as harmonics create problems and rob HP,so do sound waves that cannot flow quickly away from the head/block/crank-harmonic's are vibration waves like exhaust sound waves...the sound waves can only add to harmonic problems of engines if the sound waves cannot move away from the engine and not back to engine-especially the Inline 6 ..this can be confirmed in MANY books written on exhaust and tuning exhaust for HP....also find as many "old school" 6 cylinder engine builders-street,hotrod and racing-they have more info than you can imagine....if the sound waves hurt your ears, what are the sound vibrations doing to the engine???
again its how you build your engine and what goal you have....I will say the 2 most important addition's I have seen on my Inline experience,is when i had my 1st Long tube headers on my stock 250 years ago and then what I consider is the most dramatic change to these Chevy Inline engine's - the Bolt-In Lump.... I will thank those who have have inquired about them and am also surprized by those that send me "not so friendly" email about them ....now if I told you what "old school" engine techniques are in my 292 drag truck that is built and running, some would say "that will never work!!!"..it was good for 9 sec quarters in 2800 lb Nova's 20 years ago with engines that didnt have heads as good as the WAY OUT Bolt-IN Lump head mods I have learned from PES....its so amazing what keeps happening and I feel lucky.....Lets Have FUNNNN!!!!

Lee

[This message has been edited by LeeLites (edited 12-30-2003).]

Alot depends on what gearing you are running especially in street applications. A thing to remember is that POWER-what we typically associate with the engines ability to move the car up a hill--is measured as function of torque and rpm----and rpm is directly a function of gearing.

Lee I will have to agree with you on the sound wave matter. It WILL losen Parts Just like the harmonics that seem to plague our Inlines. At one time When My headers were not of equal lenght and the collecter Ended right along side my tranny(& bell housing area) Things came lose Like shifter, some linkage to name a few and All had lock washers or some type of locktight. Once I tuned everything Meaning tube lenght and collectors I never once had this issue again. And cliffords headers Are Far from being of Equal length. And as for who sells what headers any more I'm not realy sure, Because i build my own headers Now It's cheaper at half the cost And I know they are of equal lenght. And I mit add much easier to install around the linkage now as well and a little more ground clearance Then what cliffords long tubes are for the chevy2s( seeing that I smashed my tubes the first nite out with them On a manhole cover) they said I needed 14in. tire which I had. But they just sat to low under the draglink and I hit the first tube In the first set of 3 that pass under the draglink.So that is what prompt me into learning how to build headers.Plus i wanted a equal tubes. Hope this helps }[oooooo]



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NovaMan/Twisted6/Larry