R16 Horsepower Curiosity for Stroker and Race engines

[Pjackb]

Thanks for the input, I was really just curious. I'm not in a hurry to rebuild my engine. But, if or when the time comes, I know I would want to do it right and do what I can to increase the power. With that being said, I don't think I would object to an engine/trans swap as well. Still just trying to get my car on the road, so really no hurry, just curiosity.

Thanks again.

You have some really fast cars in your list so you can get your speed fix fairly easily.
a well built stroker nothing crazy will be relatively cheap and will run 80-90 mph all day which is really fast in these cars
Good luck with whatever you do and take the time to look at the stroker and dyno threads, lots of good info

[70MTRoadster]

I built a stroker and posted it made 83 hp at the wheels. Stock alloy head and valves, valve springs, reground cam from American cam regrinding ( I believe), stock carbs and header, bored .020 over with aftermarket slightly dished pistons. Look it up under 70MTRoadster. Scott

[JT68]

Hi JT: is that a bolt on for the 5 main stroker crank, and I'm looking for something around the 15 to 17 lbs range that some others are using,....10 lbs sounds awesome for racing, but mine needs to be happier on the street,...LOL !

We have the 9.5lb for race use. Yes.

The 10lb is amazing for street since you pick up a pound with the bigger pressure plate. Its pretty much perfect, definitely not TOO light for street. I wager you will find it is the best money you spend on the stroker. You would have to spend 3 or 4 times the money in engine mods to make the same difference in actual performance. Money back if you don't love it.

PJack has already described it well. Don't take my word for it- check with Nick Mack and Glenn (augsburger), if you would like more input on how well it behaves in a street car. (None of them race except between stoplights)

Lightening the boat anchor won't compare to the purpose built piece in any regard.

[RCMike]

Both do not compare to the one I had in my E36 M3 , that was not fun had it had about a 1/2 inch of travel and everyone no exception that drove the car the first time stalled

I could be completely wrong, but I would say this has more to do with the clutch bolted to the flywheel, than the flywheel itself..

I have 2 race engines with ridiculous like 8 pound flywheels..

One is beyond easy to get rolling. One is just about impossible. Difference between them is the clutch. the 5 inch Tilton double disc is literally a light switch. Its either on or off, there is ZERO slip. The 7 inch Tilton is controllable to get rolling.

Otherwise, interesting discussion. Love the numbers.

[Daryl Smith]

"1840cc R16 undergoing engine dyno testing. 38 mm Hitachis. Long 4-1 pipes. 120 hp @ 6000. 212 ft/lbs @ 4000."

Okay, no disrespect to Lou and what he's doing, but this doesn't add up!
(rpmxTQ)/5252 = HP

(4000 x 212)/5252 = 161.5 HP
That is 161.5 HP at 4000 rpm with 212 ft/lbs of torque.....

To be clear, horsepower is a calculation BASED on torque measurements.

TQ = (HP x 5252)/RPM
(120 x 5252)/6000 = 105 Ft/lbs
So....in 2000 rpm we've lost 41.5 HP and 107 ft/lbs of torque??

1) Simply put this is NOT POSSIBLE!!!
2) imo, that amount of torque would very likely break the 3 main 1500 crank.

If these are the readings off a dyno, somebodies dyno needs a tuneup!!

[JT68]

yes, something seems wrong with the math. Just as a reality check, 212 seems way out of feasibility for an 1840 roadster engine. I also get 105ft-lbs which makes much more sense since an R16 making 96 is 84ft-lbs at 6k. U20 making 150hp is 131ft-lbs at 6k.

We know the torque didn't more than double (at any rpm) by adding 240cc. I think something got lost in translation/calculation. Maybe there was metric-sae conversion mistake etc. Something is off.

[JT68]

I heard from Lou. Thought it was something simple. Not 212ft-lbs, 121 for the 1840. Just a typo.

He also said his last 2005cc R/H-20 did 140HP and 140ft-lbs with the 1.6 SU's (corrected)

Those numbers sound right on-no BS- and measured at 6k. Those are useful street numbers, while 7500/8k measurements are really just useful for race cars.

I'll bet the 1840 is all kinds of fun- very light rotating mass. Thanks Lou!

[23yrRebuild]

This is now beginning to sound useful. Are there any other specs about this "Lou engine", we can know about ?
CR / Crankshaft, Rods, Pistons, Valves, valve springs, porting work, exhaust, and of course the cam specs. Also, any lightening to the crank or flywheel.
What all went into making this 140 HP Stroker....Please Lou, tell us ALL about it !
Knowing about the displacement and that it's using good ole fashion 2L carbs is a great start....thanks from me....
Mike

[RCMike]

I heard from Lou. Thought it was something simple. Not 212ft-lbs, 121 for the 1840. Just a typo.

He also said his last 2005cc R/H-20 did 140HP and 140ft-lbs with the 2L SU's.

Those numbers sound right on-no BS- and measured at 6k. Those are useful street numbers, while 7500/8k measurements are really just useful for race cars.

I'll bet the 1840 is all kinds of fun- very light rotating mass. Thanks Lou!

That makes perfect sense.. I was wondering what kind of diesel numbers we were talking about on the other..

[Tomc18]

My road car stroker was a PO build back in the 80's. Ran like a dog when i got it,but sorting out the timing and initially replacing the needles on the SU's it had and then junking them for some U20 carbs improved it. Ran it on a chassis dyno when I was trying to sort the SU's at 106hp and it feels stronger with the Hitachis, but I haven't re-run it for numbers - likely 110 or so at the wheels, about 130 flywheel. According to the info I got with the car, I think the valves were 2mm oversize, and the before and after flowbench figures were there, but the paperwork is locked away in my factory at the moment, I remember it claimed it should be good for 145hp+ (got to love flow figures) When we are unlocked I can post some more details

I have the original cam specs (Thomas Cams 4D298) so it's 214 degrees measured at .050" lift, .282" total lift, .015" clearances - it is very sensitive to clearance. Until I pull the head off, that's all I know, but it is definitely fun to drive around

I speak with Lou most days, he built my 226hp U20 stroker race engine. That's real world engine dyno numbers, Also checked in the car which made 182hp at the wheels on the same chassis dyno I ran the road car on - it's just a bit quicker. For H20/R16 stroker builds Lou sells a lightweight rod/flat top piston set (about .5kg lighter per cylinder) pretty cheaply that he used to get the 140/140 numbers, same as go into his 175hp U20 builds

I was suggesting he sell a kit with a H20 crank, but they are starting to become scarce even here in Aus now, and the shipping on cranks is $$. Would make a pretty easy upgrade.

cheers
Tom