Inline six. Torque monster? How come?

Just out of curiosity, what what's the weight difference in the 6's and the 8's? Looks to me like the V-8's would be quite a bit lighter.

And if you want to know if 6s can run, you might google Glen Self from Durant Oklahoma. But he can make a V-6 and V-8 run too. I always heard that an engine doesn't know what name is on the valve cover, they might not know how many cylinders they have either.
Larry T

 

I won't debate the power potential of these engines......I do know that a hobbyist builder can put together a 350 Chevy and get 375 HP without needing a cam more than 220 degrees duration at .050. or more than 9.5 compression.This engine will idle nice at 750 rpm and have 400 pounds of torque over a wide RPM range. This would be a roller cam engine,no big deal as there are millions of roller cam blocks out there..The amatuer can do this for less than 2000 bucks including machining.All these parts can be found used within 20 miles of my house.New parts are everywhere,a click of the mouse.
383 Mopar? Not many left in these parts.And used parts are more expensive and harder to find for a guy like me.People horde this stuff and it doesn't go cheap.
That,and the BB Mopar is a larger and heavier engine with far less options on external stuff like headers and clutch housings.

 

I plan on finding out for myself: I'm putting together a "bobber" truck running a Chevy 250 I6.

 

Is it just the Aussie Ford I-6's that came with a crossflow head or did some American motors get them too??

 

I guess it depends where you are.
In America V8 engines and parts for them are a lot cheaper and more readily available than in many other parts of the world. Gasoline is a lot cheaper too in the US, and that is very significant.
When gasoline is $10.00 per gallon as it already is NOW in most other countries, a carby cast iron big block day driver may not be so wonderful.
In Japan, Australia and Europe there are some really excellent high technology, high horsepower I6 engines that would be both rare and expensive to modify in the US.
Many high performance I6 cars with excellent engines never made it to the US, because they were only ever made right hand drive.
So you guys get to play with your SBCs, and we have just as much fun, and go just as fast with our I6's.
And don't forget the DOHC four valve I4's and rotaries too, some of those are as light as a feather and make insane power when highly turbocharged.

 

I have been having hot rods for a long time. Mostly on the salt. My first time at Bonneville was in 66. But I had had drag Altered coups for 12 or 13 years by then. I have run GMC sixs and Ford and Pontiac and Packard V8s as well as Chrysler and Dodge Hemi V8s. I ran a Nissan 3 liter V6 SOHC and went 231 mph. I have run Pinto and Lotus four cylinder engines as well as 1932 Plymouth four bangers both flathead and ohv conversion. Now I am working on a Dodge Bros/ Morton & Brett OHV conversion for the salt. You know which one I liked the best? The one I was running at the time. Every one was a challange. Every one was fun. and they were all fast. Sometimes fast is 113mph and some times it's 231 mph. So much for this discussion.

 

Never better than a V8.Heavyer. les power. longer. higher.
and sounds like a trumpet out of tone
But if you like a I6 its better for you

 

Ok You're right on 2 points:Longer and higher : Yes they are.

Heavier?????? My AMC inline WITH auto-trans and starter is 15 kg's lighter (and that is with oil in both engine and trans) then a Chevy SB without trans or starter (no oil)

And for the less power-statement = Your welcome to my part of Sweden and try it out,bring Your car with the tugboat-engine and line up...

And b'out the sound thing:I think they sound nice,my sounds a bit like a Yamasukisaki-thing when revved to 7000+ rpm

 

Turn the question around; Is a V8 better for a hot rod than an L6?......

The same old questions with the same old answers. Answer to either question is; run what you like.

Someday I want to build an L4, but the L6 motors I currently have in my Jalopies are there to stay. There is no requirement that I can think of at the moment where I would ever need a V8 for a jalopy. I have two L6s and am building another.

Economics is part of it. Are my 250 and 292 Chivvys more economical than any V8? Yep, it's a no-brainer. 6 pistons. 6 sets of rings. One head. 12 rocker arms. 12 valves. 12 tappets. Easier to work on? Yep. Run like a bat out of hell? Yep.

No, they don't have more, or less torque than a V8 of equal hp. Is the peak torque on a stock motor usually at a different rpm than most stock V8s? Yep. But that's a gearing/camming issue to be figured out depending on application.

 

Will you be my mentor?

 

But a Ford sb is 65 kg lighter then a Chevy sb that make it 50 kg lighter
than yours
And if you make it rev 7000 rpm it whop the ass of your amc six
and a AMC 8 at 7000 rpm whop your six to
What have you don to your AMC six?
we have to compare stock 6 to stock 8
and hotroded 6 to hotroded 8 havent we?
and i dont like yamasuki sound att all.
Wounder in wich car i have a tugboat engine
THATS a torque monster but newer seen a tugboat
with a six

ps i think my stock mercedes V8 whop your six to

 

Sure if it don't cost me anything. You want to drive a Packard powered Vega?

 

I guess I should have asked a different way; considering the typical round-town driving and the usual traffic light/stop-go that that we all have to put up with, does an inline 6 make for a better stop light-to-stop light powerplant in a lightweight (2500 pounds) rod?

The 300 hp sbc I have in my 55 truck hauls it real good (manual trans). I'm wondering how different the I6 will be in a slightly lighter vehicle (with an auto trans).

Maybe the answer will have to wait til I build it and try it out.

 

Come on Louise!!

Everyone knows the engine that gets the most magic fairy dust will make the most power.......

Wow, I made it through about 2 pages of this thread and saw more "I think therefore it is" reasoning than I have seen in quite a while. My brother in law used to be king of this kind of thinking, but it appears to be a little more widespread than I thought...

 

We would have to see. I'm not into racing per-se. I'm not a serious competetor at all, just playing with cars in my old age, but my jalopies are no slouches either.
Getting off the light up to posted, I've beat a few, a few have beat me.
But, I haven't had a ticket for speeding or careless or evading, am pretty conservative, so that don't tell you much does it?

I'm expecting the 292 Chivvy I'm building now to compete with the average street V8.

 

How does that work? I agree that the piston does move more slowly in the bore as it approaches TDC, having reached maximum velocity at 90deg BTDC.

How do you go about speeding up the piston movement through BDC? Seeing that the crankshaft pin traces a circle in its rotation, the same piston speeds should occur at the top AND the bottom of the stroke.

 

Put it this way,pure racing engines have very long rods in relation to the stroke.A typical American V-8 has a rod that is about 1.75 times longer than the stroke.Racing engines have ratios around 2.5 even Formula one engines making power above 16,000 rpm. It a long rod wasn't an advantage,no matter how slight,racing engine builders wouldn't do it.

 

Exactly, which was my point regarding bore/stroke ratio. As best I can figure a long rod should act similarly to a short stroke, and a short rod a long stroke insofar as side-loading on the cylinder walls and piston dwell/speed...but I could be wrong.

 

A good example is the common SBC 5.7 inch rod.If possible,a 6 inch rod gives a slight increase in torque.Probably makes no difference in a street engine.I don't build racing engines,I read this stuff from guys that do build them for a living.

 

The rod length thing is very overblown. Mopars have the best so If I was prejudiced I could jump up and down and piont to them but having said that SBchevs and BBC which have terrible rod ratios but still make good power and dont seem to be hampered in any way. Someone said if it wasnt true engine builders wouldnt do it. I would put no credence in that either. Engine building is fraught with myth and black magic and so called speed secrets just like everything else. There is an advantage to a longer rod but it is so minor that it isnt worth worrying about unless you are in a position to lengthen it at little extra expense. .
A 360 dodge has a 3.58 stroke and a 6.135 long rod (I am working from memory but i know the rod length is very close to that of a 454 chev and i think that is about right. That gives a 1.71 in the dodge and 1.53 in the chev BB. A 383 mopar has a 6.58 rod length and a 383 chev has a 5.7 usually . That gives a 1.946 in the mopar and 1.52 in the chev and yet I would have to pay chev guys a fortune to change to the Mopars right? In fact they would not . Bottom line it is an interesting deal and if you are in a position to run a longer rod without excessive expense do it but otherwise dont worry about it. It is a very very minor part of engine building. The biggest speed secret for any engine be it 6 or V8 or whatever is matching ALL the components to the combination. There is far more power to be had right there than there would be fooling wth rod lengths in a 100 engines.
Cam to compression ratio or Compresssion ratio to cam duration , Head flow to RPM requirements , Cam duration to RPM requirements Carb size to engine pumping demands (CFM to CFM) Ignition timing curves to cam design .Carb jetting to engne requirments and last but certainly not least CAM charchteristic to torque converter stall . This is the stuff that gets left in the dust almost everytime some magazine guru does an engine article with the trick of the month stuff. Who does this stuff then? The guys you see at the track who claim they are running basically a stock combo or similar and are blowing everyones doors off . The guys you heard someone say about "No way that is a stock based motor. I Know for sure he has big roller cam in it and I am sure it is a stroker! " You know who i am talking about . Every track has a couple these guys. These are the guys to learn from. Not only do they know what IS important they also know what is NOT.
Don
The first Old Reliable engine 440 BTW cost me $1685 (carbs (2 x 4) to oil pan)and ran mid 11s in a #4150 74 charger. Some may have seen the video of it running on Dropshots. I probably dont have that or about that in the senior dragster in total. if you think it is not fun running low buck stuff that is competitive you haven yet discovered FUN. 6 cylinders are the ultimate form of this.
Do we run sixes to tick off the competition when we beat them? Probably if we are honest , yes.

 

Beatnik Pirate, I've often wondered... are you in the Beatniks car club?

My snack eating pal Jack Rudy (Beatniks CC) has a super cool Chevy sixer that he was always so excited about. I think he finally put it in his car or pick up, can't remember. That was a neat engine! Think there was a pic of it here too in the back of his truck at a show...

 

Dollars to doughnuts, you can't beat an LSx engine for power/weight/reliability and packaging. Aside from the power, they have a little less of the cool factor of something oddball, but if you want to go fast and not pay a weight penalty, they are hard to beat.

 

Depends on what goals you set for "good". If you're looking for "fastest for cheapest", the V-8 would be the way to go. Otherwise, everyone would be bitching about all the straight 6s being bellybutton and boring. (G)
As far as a 6 being cheaper to build because it has less cylinders, I'd have to see it on paper.
Larry T

 

It would only cost you a small amount of patience.
And yes, I would love to drive a Packard powered Vega.

 

Thanks for taking the time to share the info...this thread is becoming an excellent technical read!

Do you have any experience with the MoPar flathead 6?

 

Put $ aside, take it out of the equation. Based on the usual stop-light, around town driving and limited freeway driving (in other words, low rpm driving), is an I6 a better choice for a rod motor, in a lightweight rod? Do they develop torque at lower rpms than a V8? My sbc is happiest when it's wound up in the higher revs. If an I6 develops gobs of torque at low rpm, it would probably make for a better rod motor given the above type of driving, I would think. Is this the case?

 

OK, I'm going to ask a newby question. Why is it the Nailheads are considered to be a torquey motor compared to say, a sbc?

 

Antny- Think about a 400 SBC. That is built to be a low end motor. Either will work. Depends on you and what you like.. Biscuit--Go back to the start of this and reread what was written about rpm range inwhich the torque peak comes in. The Buick may well have less torque than some other motor (SBC) when you compair both peaks. But the Buick was built to move a very heavy car away from a stop sign in a satisfing maner. And it will. By the end of the block, here comes the Chevy. Climbing towards it's peak while the Bue is past peak.

 

The straight sixes are just built for low-RPM torque...Small bore, long stroke, low-RPM cam, small valves and ports, small carb, heavy flywheel. It's not that they make more torque than the average V8, but that they make it at such low RPM. And those are all the same reasons why a stock I-6 doesn't rev very high. It does what it was designed to do.

 

Keep in mind that, no matter what you do to the average I-6, you are still dealing with a long, and relatively twisty, crankshaft that typically doesn't have very many main bearings supporting it. Not the best combination for high-RPM use. Again, they were designed for economical low-speed work. And for that, they're great.