bore vs stroke

[louisb]

Given two engines of the similar size, would you rather have a larger bore or stroke? Would you run same the cam and heads on them or pick a different combo?

Example:

74 stroke X 90.5 bore
69 stroke X 94 bore

or

82 stroke X 90.5 bore
78 stroke X 94 bore

How about for a full weight sedan vs a lightened car? I know I left out a lot of variables. just something to think about.

--louis

[Zach Gomulka]

I like the big bore because it helps unshroud the valves so the heads breathe better. I also wouldnt use a stroker crank shorter than 78mm... its difficult to get the deck height set, A pistons are too tall, B pistons are too short. And lastly, if you are gonna bore it out, might as well go 94. Same price, mo powa!
All this applies unless you are building a STF motor, or you are a goofy, period performance nut like I am, thats why the GTV will eventually get a 1679cc, my '67 a 1835cc, and some other car I build down the line will get a 2180cc (hey, when you come across NOS 92mm birals, you use them!!)

[louisb]

The two examples were more to illustrate the different ways you can get close to the same size engine. Okay, lets throw in another variable. How about we limit the carb choices to a 40 duals or 48 duals. (Make is unimportant here.) Could even get real weird and limit it to a single center mount too. There are a lot of ways you could change this to make the combos behave differently.

Say you take the 82 x 90.5 combo w/ the 40s. That sounds like a good motor for a bus or TIII. Put 48s on there and put it in a light bug and its a different animal. Would you rather have 48s on a 74 x 88 or a 69 x 90.5 (or even 94)? And we have not even gotten into cams.

--louis

[nicolas]

from what i know a larger stroke will lead to more torque. that is a very simplistic vieuw but it holds true to some point. but you also asked about cams and heads. that changes a lot depending on the combo you use. a cam like a W110 works really well in a 1641 but you get something like a tractor engine if you put it in a 2276 engine. in an engine that has the same cc's but a different stroke and PC, it also can matter as with the different combo the speed of the pistons changes also. so it does matter. but what matters even more is the heads and cam combo. if the heads can't flow the air and fuel there is no way the bigger cam can work in any engine. as it is said before the power is in the heads.
just look at the different combo's  that are built. Jim Ratto's and Greg Brinton's engine are both 78 x 94 and for instance gary bergs car was a 82 x 90.5 engine. they don't differ much in cc's from eachother, but they will work differently and there powerbands will be at different rpms.
hope this isn't too far off, but there is more to take into account 

[Steve D.]

Bigger bore breathes better 

[louisb]

It is all pretty much wide open. I am just trying to spark some conversation about different combos. It mostly started after reading the rags to ripper engine article and thinking what would be better. It or a 69 x 92. How all the components work together in an engine has always fascinated me.

--louis

[Jim Ratto]

The age old question....

So much of it depends on rod length, which determines piston acceleration and velocity.

I think a street car, with all its weight, needs long stroke to give it the torque. Think about how weak a stock motor feels, when you encounter a grade, even if it has Kadrons. A lot of this has to do with the stroke and also cam (on a stock motor, you're also restricted by the carb and the tiny manifold). If you add displacement by stroking it, the motor will gain more torque, through simple leverage, but also, the cylinders are going to pull fuel/air charge in "harder."

[louisb]

Bigger bore breathes better 

Ferrari engines, along with a lot of v12s, use much smaller pistons than a comparably sized v8 with larger pistons. They tend to breath pretty well and can get up high in the rpms. I know we are talking about different sized 4cyl engines so that probably doesn't apply. Just a random thought.

--louis

[Zach Gomulka]

Im not totally sure what you're getting at. Given what I said earlier, Id obviously like the 94x69 motor over a 88x74... unless its some goofy, period correct thing Im building

For a sane person (unlike myself ) there are only a few motors worth building, IMO:
1600. Cheap to build and keep going. Can be quick if done right.
1915. Best bang for the high performance buck, by far.
2165. If you want a stroker and want to keep the engine narrow (for early cars), or trust a welded and stroked VW crank over a chinese one piece. (I dont advise going past 78 with welded strokers, but thats a different story)
2276. Great big motor. Excellent rod ratio with short rods. Motor stays stock width. Structural integrity of the case and crank is retained. Larger strokes require longer rods, then the motor gets wider and it is harder to get the ideal rod ratio back.

Those are the base displacements. Add whatever cam, rockers, heads, carbs and exhaust to get the motor to do what you want it to do.

[Zach Gomulka]

Bigger bore breathes better 

Ferrari engines, along with a lot of v12s, use much smaller pistons than a comparably sized v8 with larger pistons. They tend to breath pretty well and can get up high in the rpms. I know we are talking about different sized 4cyl engines so that probably doesn't apply. Just a random thought.

--louis

They also have 4 or 5 valves per cylinder!!

[louisb]

Not the 60s versions. I am not really looking at a specific engine combo. More just starting a conversation on the different ways you can build the same size engine and what the different characteristics are going to be. Well, that and its rainy here today and I am bored at work. As for the engine sizes you listed, it used to not be so cookie cutter. You read some of the older mags and there were a lot of different combos being run. Now days it seems everyone has a 12 sec 2276. give me the engine size for almost any engine in a car featured this year in HVWs or Ultra VWs and I can probably tell you when parts they used without even looking at the mag. Is there no innovation in VW engine building anymore?

--louis

[Jim Ratto]

Bigger bore breathes better 

Ferrari engines, along with a lot of v12s, use much smaller pistons than a comparably sized v8 with larger pistons. They tend to breath pretty well and can get up high in the rpms. I know we are talking about different sized 4cyl engines so that probably doesn't apply. Just a random thought.

--louis

Ferrari engines use 180' cranks and small single cylinder displacement to allow these motors to make horsepower thru elevated rpms (we all know hp is a product of RPM). The smaller bores allow smaller "lungs" which are easier to fill at elevated rpms, even with relatively sedate valve timing. Multiply all of those "small lungs" by 12 and you have a big hp engine. With a VW we are limited to 4 cylinders to make power, so to make any power and torque, you have to make those cylinders big, and the makes it so much more difficult to fill those big lungs at high rpm.
There is a definite science to it.
In fact there is a formula that can be utilized to determine valve area required to make a level of horsepower at a given rpm.
For a Volkswagen street car, that you don't want to wind up to 7500rpm to make power, just build it as big as practicality allows. Obviously, 94mm's are the way to go, no matter which crank stroke you use.
When somebody asks me what to build if they are on a budget, and aren't familiar with building big cc VW's, I ALWAYS suggest a 1914. They run hard if cammed right, and are a simple motor to build.

[Zach Gomulka]

Not the 60s versions. I am not really looking at a specific engine combo. More just starting a conversation on the different ways you can build the same size engine and what the different characteristics are going to be. Well, that and its rainy here today and I am bored at work. As for the engine sizes you listed, it used to not be so cookie cutter. You read some of the older mags and there were a lot of different combos being run. Now days it seems everyone has a 12 sec 2276. give me the engine size for almost any engine in a car featured this year in HVWs or Ultra VWs and I can probably tell you when parts they used without even looking at the mag. Is there no innovation in VW engine building anymore?

--louis

Those engines were designed from the get-go to be free revvers. The Volkswagen?? Not so much!!
There were alot of "interesting" engines back then, because the VW high performance industry was still teething. I think I can safely say that now, we have it pretty much down packed as to what works and what doesnt. A N/A race car was doing pretty good if it made 200hp 35 years ago, and that motor was like a grenade with the pin pulled!! Now we have street motors making that much power, and more, on pump gas, that you could drive across the country!!

[louisb]

Okay, so what is the next step in the evolution? Monster 3 liter NA motors with Berg 58s? Or should we all just go turbo?

--louis

[Zach Gomulka]

Turbos? Bahhh. IMO, the VW engine is reaching its peak in evolution. Think about it, its design dates back to the 1930's and its been hot rodded (first by Porsche) since the late '40s. Its been tweaked and tuned for almost 60 years! There isnt much left to do that already hasnt been done. I dont mean to piss on your campfire, but thats just the way I see it. I dont think that many of us are here because we want the latest and greatest in technology
I think there is more power to be found in valvesprings, cam design, and heads... Multiple valves per cylinder.

[Jim Ratto]

Turbos? Bahhh. IMO, the VW engine is reaching its peak in evolution. Think about it, its design dates back to the 1930's and its been hot rodded (first by Porsche) since the late '40s. Its been tweaked and tuned for almost 60 years! There isnt much left to do that already hasnt been done. I dont mean to piss on your campfire, but thats just the way I see it. I dont think that many of us are here because we want the latest and greatest in technology
I think there is more power to be found in valvesprings, cam design, and heads... Multiple valves per cylinder.

yeah really... once you've got over 150hp or so in a Bug...how much faster do you want to go?
I think there are so few "street" motors out there that have reached the magic 100hp per liter number, that it's a pretty good indication that the poor little Volkswagen has reached its hp peak.... so many "real" competition motors have been able to cross the 100hp/liter border since the 1940's.

louis.... I think alot of the "copycat" motors that you are seeing (and I am glad you have brought this up) are the result of the industry taking a shift from where it was 15-20 years ago. Open any Hot VWs in the last 18 months or so....look at the ads...they are all catering to the "Rennkafer" phenomenon. Fifteen years ago when I used to take my car to Bug shows and the drags at Sears Point, I was sometimes the only car there sporting 48IDAs. Or maybe 1 of 4 street cars that were racing. Now I haven't been to Sac in years and years, so I don't know, but I bet there are mile long lines of street cars racing. So the industry has taken note and figured out they can make money capturing the desire of so many guys that want to do the "Rennkafer" thing to their cars.... 
Back in the 70's and 80's there were no such thing as off-the-shelf CNC ported "wedgeports"....sure you could buy Street Eliminators but they needed hours of hand work. My point is guys can satisfy their "I want it NOW" needs today. They can just click online, 82mm crank, 5.400" race rods, 94mm p/c set, FK89 cam, 48IDAs, CNC heads, turbo muffler....click...bing bang it's a 200hp motor at your doorstep.

[louisb]

they are all catering to the "Rennkafer" phenomenon.

These days there are very few "street cars" in RKF. But yeah I agree with you. If you go on the Samba there are advertisements for 3 or 4 engine builders/head porters guaranteeing 200+ hp engines that will run on street gas.

--louis

[Jim Ratto]

they are all catering to the "Rennkafer" phenomenon.

These days there are very few "street cars" in RKF. But yeah I agree with you. If you go on the Samba there are advertisements for 3 or 4 engine builders/head porters guaranteeing 200+ hp engines that will run on street gas.

--louis

What kind of motor are looking to build, louis?

[louisb]

This post is more a mental exercise to discuss different engine specs, combos, trends. I am not really looking for a specific engine out of this post. But since you asked, for the '67 I keep vacillating between a couple of different combos:

The vintage option. Would be great drive. I like this one when I am in a vintage/inexpensive mood but I think I would want more power after a while.
74 x 88
w120
Single Port heads w/ stock valves, port & polish
Kads
100ish hp
1 3/8 header
stock geared tranny w/ welded 3rd & 4rth

The middle ground. More expensive since I don't have IDAs. Still a reasonable engine to build. This is right out of the HVW engine book. Maybe 14s with this engine?
78 x 90.5 or 94
w125 (Actually probably a web 110)
40 x 35 heads
IDAs
140/150ish hp
1 1/2 header
stock geared tranny w/ welded 3rd & 4rth

When I am suffering from Baddest car in the Valley syndrome I like this one: Much more expensive though, but I am sure it would be a kick in the pants and would probably be close to my ceiling for a street car. The engine or tranny I could have done by next summer. The rest will take another year or so:
82 x 94
Web 86c
42 x 35 (37?) heads
IDAs w/ 42 vents
190ish hp with the right set of heads
1 3/4
Berg 5 close 1-4 stock 5th.

It all comes down to home much do I want to spend and how long do I want to wait to save up the dead presidents to pay for it. None are real original except maybe the first one. Course I could always use the set of 94mm squishie pistons and 86b cam I have had sitting around for about five years. I just hate the idea of being locked into a head porter. 

--louis

[Jim Ratto]

This post is more a mental exercise to discuss different engine specs, combos, trends. I am not really looking for a specific engine out of this post. But since you asked, for the '67 I keep vacillating between a couple of different combos:

The vintage option. Would be great drive. I like this one when I am in a vintage/inexpensive mood but I think I would want more power after a while.
74 x 88
w120
Single Port heads w/ stock valves, port & polish
Kads
100ish hp
1 3/8 header
stock geared tranny w/ welded 3rd & 4rth

The middle ground. More expensive since I don't have IDAs. Still a reasonable engine to build. This is right out of the HVW engine book. Maybe 14s with this engine?
78 x 90.5 or 94
w125 (Actually probably a web 110)
40 x 35 heads
IDAs
140/150ish hp
1 1/2 header
stock geared tranny w/ welded 3rd & 4rth

When I am suffering from Baddest car in the Valley syndrome I like this one: Much more expensive though, but I am sure it would be a kick in the pants and would probably be close to my ceiling for a street car. The engine or tranny I could have done by next summer. The rest will take another year or so:
82 x 94
Web 86c
42 x 35 (37?) heads
IDAs w/ 42 vents
190ish hp with the right set of heads
1 3/4
Berg 5 close 1-4 stock 5th.

It all comes down to home much do I want to spend and how long do I want to wait to save up the dead presidents to pay for it. None are real original except maybe the first one. Course I could always use the set of 94mm squishie pistons and 86b cam I have had sitting around for about five years. I just hate the idea of being locked into a head porter. 

--louis

I had this exact motor in my '67 in the early 90's. Except 44IDFs.

78 x 90.5 or 94
w125 (Actually probably a web 110)
40 x 35 heads
IDAs
140/150ish hp
1 1/2 header
stock geared tranny w/ welded 3rd & 4rth

For a driver, it was probably the most fun out of all of them, maybe it was just because it was the first "big jump" for displacement under my young right foot. But this was the motor sheep and I went to Phoenix with, and it ran very well. The ability to blow by slower traffic on Interstate 5 was what impressed me so much, compared to the 1641 it had replaced. It would run very happily at around 3800rpm on the highway, under 180F, get 23mpg, and if I just tickled my toes against the gas pedal it would roar up to 4500rpm in an instant. It really was just a sweet driver.

[Steve D.]

Somebody explain to me why stroke is going to make more torque than bore.  I've heard the argument time and time again that "the longer arm is a bigger lever" and stuff like that, but I'm not so sure that I believe it.  Here's why:

The torque you are going to get out of a motor is going to be the cylinder pressure acting on the crank.  When you put a longer stroke crank in the motor, the journal is going to be further from the centerline at 90* after TDC, giving you the "longer lever" argument.  The catch is, on a gasoline motor the majority of the cylinder pressure is just a few degrees after TDC (~13* or so if I remember back to when I used to know this stuff).  So when you have this 6.5mm "longer lever" (82mm - 69mm/2 (stroke is back AND forth)) and you apply it to the peak cylinder pressure at 13* or whatever after TDC, then what kind of mechanical advantage do you have left?

If you go with bigger bore, you can develop the same cylinder pressure but apply it over a much larger surface area.  As a bonus, the bigger bore leaves more area between the cylinder wall and the edge of the intake/exhaust valve, letting it breathe better and increasing the volumetric efficiency.

So the way I see it, bore and stroke both make bigger CC's, which is great.  Stroke makes the motor wider, so anything over 86mm really starts to run out of real estate inside the case and can also make the motor super wide (I know, you can put a 92mm crank in blah blah, and short rod this, and pin height that, I'm just going general here).  Bore keeps the motor narrow, improves VE, and allows more room for even bigger valves if needed, and consequently even BETTER VE.

As far as advancements, you aren't going to spin this relics to 9,500rpm and have them live on the street, turbos are a plumbing headache, sound like popcorn machines, and have all the asthetic appeal of a big spider humping the back of your car- you can go with a CB style deal with injection but that's just $$$$, and you still lose the simplicity and character of an old VW.  So if you aren't going to spin them any higher or pressurize them, the only way to go is BIG, and I think Jeff Denham has knocked this one out of the park.  His pump gas street motor is making gobs of power and mountains of torque all while being set on "snooze".  If he ever popped that thing apart and went RennKafer style on it with a big gulp camshaft and C12 compression it would blow people's minds (not to say that it hasn't already).

For me, I think the way to go are big lazy motors- build it big, build it lame, it will make big power effortlessly and drive around the planet on kerosene and not eat itself in the process.

Let's hear what you have to say, this is just my opinion and that's all- just an opinion.  If you do debate/educate me, please keep the engineering equations out of it, I prefer to speek in layman's so we all know what's going on.

 

[Bill Schwimmer]

Just like my 2275 was the prototype for the modern Cal Look/ Hot Rod VW motor when i built it 15 yrs ago... Jeff Denham's & Steve Dalton's  2.8-3.1L motors are the prototypes for the next generation of N/A street performance motors. I would be willing to bet that within the next 5-10 yrs 4" bore motors will be commonplace.  250 hp on 91 octane gas ? These guys are doing it right now..I found it amusing on the other forum that Steve D.'s performance @ LV dyno day did'nt raise an eyebrow. They did'nt understand that history was being made. Steve later made a jet change & it pulled 204hp @ the wheels, with the belt on ,91 oct Cali gas & at about 4000 feet or so elevation. Think about it..  That was the most impressive feat I have seen in a long time. I hope the CB performances & Gene Berg Enterprises of the world take notice & start making the stuff to do it available @ a reasonable cost.   Sorry to spill the beans for you Steve  & sorry for rambling    Bill

[louisb]

Okay, the cat's outof the bag Steve. Spill the beans on what you got in that motor.

Oh, and I hardly ever read the CLF so I missed the thread on the Dyno day. Have to go check it out. Maybe someone will show up with one of these motors for the next engine build off.

--louis

[The Ideaman]

Wow, that makes a lot more sense to me.  I thought he was doing it with a 2332.

[louisb]

Just like my 2275 was the prototype for the modern Cal Look/ Hot Rod VW motor when i built it 15 yrs ago... J

Not only is your motor the prototype for most of the modern Cal Look / Hot Rod VW motors, but your car is pretty much the prototype for the current trend in Cal -look style with stock trim, brms & 48s. Mason's black car would be the other car I would credit with kicking off this movement that has sort of culminated in the DRKC cars of today. I am curious what you would build today if you were starting off with a blank sheet of paper.

--louis

[Zach Gomulka]

Heres another 2 cents worth, at this rate you'll have a quarter soon!!

The vintage option. Would be great drive. I like this one when I am in a vintage/inexpensive mood but I think I would want more power after a while.
74 x 88
w120
Single Port heads w/ stock valves, port & polish
Kads
100ish hp
1 3/8 header
stock geared tranny w/ welded 3rd & 4rth

1) This motor will cost alot of money for the power you'll get out of it. 88's cost more than 94's, and that 74 crank costs the same as a 78. 2) It will end up wide because you will have to shim the barrells out, or if you run B pistons (good luck finding those!) you will have to cut the cylinders way down to get any squish in the chamber. 3) Unless its a stocker, why build a motor with SP heads?? Dual ports cost the same and of course have the capability to breathe MUCH better than any single port, any day. 4) The cam is way out of wack with both the headflow, and the carbs. Its a 6500-7000 rpm cam in in something that will struggle to get to 5500. As soon as the cam turns on, the motor will lay over because its sucking air through that tiny single port straw and stock valves. It will never come close to 100hp. Make it a dual port, drop in a Engle 100 x 1.25 cam, and you will LOVE it. Better yet, save a grip of cash and stroker motor headaches, and build a 1915 the same way. 100hp, and loads of torque from idle up to 5500-6000. Single port Kadrons are great for waking up a tired stocker, and thats about it.

[louisb]

Heres another 2 cents worth, at this rate you'll have a quarter soon!!

The vintage option. Would be great drive. I like this one when I am in a vintage/inexpensive mood but I think I would want more power after a while.
74 x 88
w120
Single Port heads w/ stock valves, port & polish
Kads
100ish hp
1 3/8 header
stock geared tranny w/ welded 3rd & 4rth

1) This motor will cost alot of money for the power you'll get out of it. 88's cost more than 94's, and that 74 crank costs the same as a 78. 2) It will end up wide because you will have to shim the barrells out, or if you run B pistons (good luck finding those!) you will have to cut the cylinders way down to get any squish in the chamber. 3) Unless its a stocker, why build a motor with SP heads?? Dual ports cost the same and of course have the capability to breathe MUCH better than any single port, any day. 4) The cam is way out of wack with both the headflow, and the carbs. Its a 6500-7000 rpm cam in in something that will struggle to get to 5500. As soon as the cam turns on, the motor will lay over because its sucking air through that tiny single port straw and stock valves. It will never come close to 100hp. Make it a dual port, drop in a Engle 100 x 1.25 cam, and you will LOVE it. Better yet, save a grip of cash and stroker motor headaches, and build a 1915 the same way. 100hp, and loads of torque from idle up to 5500-6000. Single port Kadrons are great for waking up a tired stocker, and thats about it.

Actually, this motor came from Dyno Don who ran one like it in the '70s. The 120 cam is designed for 1000 - 5500 so actually fits well with a maxed out set of SPs which as you say would top out at around 5,500. The small bore works with the stock sized valves, single springs and a 1 3/8 exhaust. Run a non-counter weighted crank, not needed if you don't rev above 5,500, and a 10 lbs fly wheel. The Kads with a single throat per intake port help keep the flow high. A bigger stroke or a bigger bore would be a waste with the small intake ports on the SP heads. The motor would rev like crazy, produces lots of torque and kill a lot of other bigger motors off the line. By the time you got to fourth gear the engine is done though. Again, it is all about the combo, but I agree, it is getting 100 hp the hard way. Still, I think it would be a lot of fun in a light car or even a buggy.

--louis

[Zach Gomulka]

Yeah, I know it came from Dyno, and I respect him, but there are better ways to do it now.
I think you have the 110 and the 120 mixed up when it comes to powerband. On the chart Mark Engle emailed to me, it says the 110 is for 1500-5500, and the 120 is for midrange on up. But like Ratto says, I take that with a grain of salt. In fact, the 110 is better for more revs than that. I shifted my 110 cammed 1600 at 6300, and it would easily kick the 6500 limiter in 1st and 2nd. I believe that any VW motor, reguardless of displacement, will do the same. The only difference is that the big motor will make more down low. My 1776 with a Engle fk65 (like a 100 but designed for 1.4's), would even make power up near the 6k mark. So why put a high rpm cam in a low rpm motor?? The rule of thumb is here, use the smallest cam you can that still gives you the top end you want.
10lb flywheel and non c/w crank?? Sure it will rev up REAL quick, but your bearings will be beat to a pulp in no time!! There is no downside to using a c/w crank, so why wouldnt you?
My old 1600 made 93hp with the belt on, went 14.87@88mph, and I drove the thing everywhere- in Phoenix!. Sure, it wasnt a torquer, but it did the job, and quite well I think! I really want to build a clone of this engine, it was great fun, didnt cost a bundle, was reliable, and got 30mpg on the highway. This is how I'd do it now, with a few minor updates...

DPR c/w 8 doweled crank
Forged pistons
12.5lb flywheel
FK7 cam w/ 1.4s (similar to the 110x1.25)
40 Dellortos w/ CB update kits
40x35.5 ported heads, dual springs
8.5:1
1 1/2" header, 2 1/4" muffler

Do you know how much fun it is to kick a strokers ass, or better yet a 5.0, with a 1600?! Its the reason why my plate read 1POINT6

[mr.speedwell]

i put this in my baby

78.4 x 90.5
w110/1.25
Single Port heads w/ 40-32 valves, port & polish
dual springs
stromberg cd150

11lb flywheel

1 1/2 header

[nicolas]

My old 1600 made 93hp with the belt on, went 14.87@88mph, and I drove the thing everywhere- in Phoenix!. Sure, it wasnt a torquer, but it did the job, and quite well I think! I really want to build a clone of this engine, it was great fun, didnt cost a bundle, was reliable, and got 30mpg on the highway. This is how I'd do it now, with a few minor updates...

DPR c/w 8 doweled crank
Forged pistons
12.5lb flywheel
FK7 cam w/ 1.4s (similar to the 110x1.25)
40 Dellortos w/ CB update kits
40x35.5 ported heads, dual springs
8.5:1
1 1/2" header, 2 1/4" muffler

Do you know how much fun it is to kick a strokers ass, or better yet a 5.0, with a 1600?! Its the reason why my plate read 1POINT6

hey mail me some more info on that engine if you will; i have a 1641 and it only runs 17. 56 so there is room for improvement! 

Just like my 2275 was the prototype for the modern Cal Look/ Hot Rod VW motor when i built it 15 yrs ago... Jeff Denham's & Steve Dalton's  2.8-3.1L motors are the prototypes for the next generation of N/A street performance motors. I would be willing to bet that within the next 5-10 yrs 4" bore motors will be commonplace.  250 hp on 91 octane gas ? These guys are doing it right now..I found it amusing on the other forum that Steve D.'s performance @ LV dyno day did'nt raise an eyebrow. They did'nt understand that history was being made. Steve later made a jet change & it pulled 204hp @ the wheels, with the belt on ,91 oct Cali gas & at about 4000 feet or so elevation. Think about it..  That was the most impressive feat I have seen in a long time. I hope the CB performances & Gene Berg Enterprises of the world take notice & start making the stuff to do it available @ a reasonable cost.   Sorry to spill the beans for you Steve  & sorry for rambling    Bill

no rambing Bill, this is very true. the hobby has no limits really, there have been a lot of parts made and tested in the last decades and it seems that a lot of these things are finally used in streetcars, but the guys who are setting a new benchmark never stopped testing and developing heads, headers, pistons,... and what not. it takes a long time to build very good parts that will last. and like you said, i hope they are affordable.

and i have been thinking that an engine is a reflection of what you want as well. i personally would not build a 69x94 engine. i would rather love to build a 82x88 engine, but i can't really explain why... except that dave rhoads has that combo  , that is also what makes it so great. maybe we need to do a revival of the 1776 vs 1776 engine wars like Jim told us about. but this time set for a volume and build engines around that cc with different combo's. i am thinking out loud here. but it brings us also back to the top 10 idea that came up a couple weeks ago.

love this post, it really talks about what we live for.