L-100 & 9" clutch

Ol' Ron said:
I don't thik the L-100 would work very well in a stock displacement engine in a heavy car. Torque i
s what moves the car and the long duration of the cam reduces the lowend torque. By boring and stroking the engine you increas the lowend torwue and the head work increases the CR as well. Planing an engine build you must consider the application. remember, a "Street engine " spends 90% of it's time in cruise!!!
Gramps
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Ron tell us the specs of the legendary Ambulance engine. I may even have them somewhere. Cheers.
 
Just a 276, Kong heads (one piece). Everything else was stock. @bl intale 94 carb and stock ignition. No porting or relieving Stock trams and .70 GM rear. 140" wheel base 5500 lb ambulance with a plat called "Ugly". Ran this way for several years.
Grampa
 
Has anyone here run an L100 in a 221 or 239 CI engine? It's generally considered to be 'too big' but has anyone here actually done it?
 
Yep! converted a 37 221 to 239 with an 8ba crank & Pistons . The A roadster had a T-5 and was light as a feather. Sometimes the aesthetic value of the cam is just the sound. Pretty expensive today???
 
Ol' Ron said:
Yep! converted a 37 221 to 239 with an 8ba crank & Pistons . The A roadster had a T-5 and was light as a feather. Sometimes the aesthetic value of the cam is just the sound. Pretty expensive today???
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Ron,

My friend and I just picked up 3, pumps in block 221 stud motors this weekend. If I recall, Paul's motor ran pretty strong for a small CI engine.
 
The weight of the Vehicle is where the problem lies. When trying to accelerate a heavy car the torque output of the engine is what has to do all the work. The more torque the faster the acceleration. Displacement and compression is what increases the torque, not camshafts, they just move it around!!
Gramps
 
Ol' Ron said : "Displacement and compression is what increases the torque, not camshafts, they just move it around!!"


That's a very astute observation, and pretty darned accurate too!
 
Ron's comment is pretty accurate (in a general sense). But, a specific camshaft can increase both HP and Torque - but the RPM at which they are available can be drastically different between any two cams (and engine) combinations.

Typically the more radical the cam profile (lift and especially duration), the higher the power band and torque curves are moved UP the RPM scale. It is not exactly that simple as there are many other factors -- like timing, advance, lobe centers, port volume, port velocity, header design, etc. . . . but you get the point.
 
I'd still like to hear about the pressure plate. A stock 9" PP slips in my mild 59a with merc cam, and merc crank, single carb, iron heads. I know Laurie from down under has experienced similar results
 
Here's why I asked about the L-100 in a small engine. Long ago I dealt with a customer's 327 SBC that had stock low-perf heads and a huge cam (Anyone remember the "Optional Z-28" cam that chevy sold over the counter? I was told that's what it was) The result was an engine that ran out of air just about where the cam started to work. It wasn't lack of carburetion, it had a 65 Corvette fuel injection unit on it.



So it had a super nasty sounding idle, and a soggy bottom end, and ran strong from about 4500 to 5000 rpm then distinctly stopped pulling at 5000 presumably because of the combination of 327 CI and the small heads.


Would a 221 w/L-100 do the same thing, or would it continue to make power at higher RPM?
Related question, how much rpm will 221 rods stand up to?


I understand about gearing and weight and torque curve, have dealt with that many times in many ways, I just wouldn't want to build an artificially stunted combination. (I find a high revving engine fun to drive, you don't need big torque when you have horsepower!)
 
My apology for not answering your clutch question before....to recap 286 cu in l-100 cam EAB heads with .040 clearance one 97.....all in a '32 pick up with 3:78 gears and
16 - 28 trans. 9" disc and pp from VanPelt.....zero slip and slightly less than moderate leg force required....my legs are 80 years old.Truth be told I was pleasantly surprised
how user friendly this clutch is....still happy after 2000+ miles. No mercy shown.

Charlie
 
Charlie ny said:
My apology for not answering your clutch question before....to recap 286 cu in l-100 cam EAB heads with .040 clearance one 97.....all in a '32 pick up with 3:78 gears and
16 - 28 trans. 9" disc and pp from VanPelt.....zero slip and slightly less than moderate leg force required....my legs are 80 years old.Truth be told I was pleasantly surprised
how user friendly this clutch is....still happy after 2000+ miles. No mercy shown.

Charlie
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That's good to know, Charlie. Those 9"ers are super light even compared to a 10" clutch.
 
The term "Horsepower" can't be measured! It must be calculated. Torque X RPM/ 5250. Has something to do with a horse lifting 33,000 lbs of weight over a period of time. Now the formula fussy about where the torque is at, Lots of torque at low rpm's very little hP. Not much torque at high rpm's lotsa hp. When your engine is turning hi rpms, iy's power is limited by the size of the intake port, which acts like a governor to limit airflow into the cylinder and a hot cam can't improve upon a small port. After looking at allot of dyno runs you can see the max torque drop in RPM as the displacement increases. Now add a blower and the torque increases as boost goes up. Thus more horsepower.. I think that;s why I like the 258 engines with aL-100 they'll turn 5k plus and make a fair amyt of hP.
Gramps
 
I understand. So for a given port/valve flow capacity, a smaller engine can rev higher and still make relatively good power(torque) for it's size. Where is the practical limit rpm wise for a flathead and what creates that limit - valve spring pressure, conrod strength, piston strength, crankshaft strength/flex, bearing oiling? Something else?
 
Yoyodyne said:
I understand. So for a given port/valve flow capacity, a smaller engine can rev higher and still make relatively good power(torque) for it's size. Where is the practical limit rpm wise for a flathead and what creates that limit - valve spring pressure, conrod strength, piston strength, crankshaft strength/flex, bearing oiling? Something else?
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It is a lot of things . . . really no different than building a SBC or any other engine.

On a flathead, there are multiple things that influence RPM potential:

1) Breathing: Ports, valve sizes, valve lift, duration, etc.. It takes much better air flow than stock ports and valve sizes to make much HP above 5,000 RPM.
2) Ignition: Many stock ignitions will not handle RPMs above 5,000 - unless they've been reworked by somebody who knows all the tricks.
3) Lower End Strength: The higher the RPMs, the more stress on the whole rotating assembly. Cast cranks and 3 main bearings start to become an issue - unless you've expertly setup the lower end, have larger bearing clearances, have everything balanced and have rods that can take the RPMs.
4) Clearances: Typically we open up the clearances on the bearings. If we're running stock rods, then make darn sure that things like "full floaters" actually float, etc.. At higher levels of HP and RPMs - the crank becomes a custom billet and the rods as well.
5) Crankshaft Support: Lots of us increase the strength of the center main bearing cap --- steel caps, supports, etc..

With all the above said, on my fully built engines there is no issue going to 6,000+ RPM . . . with full-on race engines pushing 7,000 (or more).

But, when you get to these higher RPMs a LOT of things come into play - starting with ALL the components in the package --> both valvetrain and lower-end:

Titanium valves, lightweight lifters (no adjustables), higher spring pressures, billet cams, custom cranks, dry-sump oiling systems, custom rods, special ignitions (mags, MSD, etc). etc..
 
Ol' Ron said:
At what RPM do you reach max torque?? engine displacement??
G
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That's what I'm getting at with my question about the L100 in a small engine. Will it make max torque before it runs out of RPM because of another limitation?
If it makes it's max at 4500, instead of 2500, I'm OK with that. In fact, that's kind of what I'm after. If it needs 7000 to reach it's optimum range, that wouldn't be a good idea for what I want to do because I don't want to build a race flathead.



100 ftlbs at 5000 is twice the HP of 100 ftlbs at 2500 RPM.
@2500 would be better for towing weight up a hill at reasonable RPM. @5000 would accelerate a lighter vehicle better.


A rising torque curve feels faster than a flat torque curve, even if the flat curve is actually more ftlbs, because the rising curve is increasing in acceleration as it rises. BTDT.
I'm just looking for something fun to drive in small doses, I'm not touring the country or spending a lot of time in traffic.
I do appreciate the input guys.
 
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Yoyodyne, To try and answer your question, I think [my opinion], the limiting factor is breathing. I have tried an L100 in a 221...I'm not particularly impressed with it. Sorry Tony!
Most everyone on here that is flathead performance [oxymoron] orientated, believes [possibly rightly so], that there is no substitute for cubic inches [apart from maybe rectangular money], but I tend to prefer developing the little 221 on account of its propensity to rev, on account of its smaller, lighter rotating/reciprocating assembly.
I've spent a major period of my life trying different engine mods, fitting said engines into the same car each time, on that eternal quest of finding out what works best.
Gearing plays a big part in the equation too...generally, I've found using the standard 28 tooth cluster and a 3.78 ratio out back, is a good combination for all round street performance.
So, how to build a sweet 221? main objective is to let it breathe! This involves the usual valve work, porting, multi carburation etc. Next is to raise the compression. Herein lies the old challenge of getting compression up without sacrificing breathing. Aim for 60cc volume in the chambers or less. Now, if you fit your desired L100 cam you'll find the valves in all probability hit the sparkplugs... the way to get maximum breathing through those convoluted passages is to raise the roof, BUT also narrow it...the chamber profile does not follow the head gasket contour. Do not relieve the block [obviously]
OK, how else do we improve the revvability of our favourite little engine? By lightening the flywheel/clutch assembly. Than get the whole kaboodle balanced.
I cannot tell you which cam to use...as previously said, I don't believe an L100 to be best choice....a stock 32 steel cam is pretty good [they have hotter timing, subsequently detuned by Ford in 35 with the introduction of the first 'fat Fords, which need more torque]. I find an Isky 88 to be a good upgrade. That's what I use. There are so many cam choices, it really becomes up to the builder of the engine, taking into account the application of the engine, and the mods done to it, to make a selection.
 
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