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Re: Actual HP numbers
Posted by: 63turbo ()
Date: November 15, 2020 08:06PM

tomkeo Wrote:
-------------------------------------------------------
> Here's the math. HP = Torque X RPM (divided by) 5250. Looking at the dyno curve Dave posted, you would need OVER 500 lb/ft of torque at 3500 rpm in order to produce 350 HP at that speed as shown on the graph. Not very likely, even with an E-flow compressor. Matt is right, at wide open throttle and the same boost level, there will be very little difference in HP between FI and carburetor.
> As far a true horse power rating, Hugh MacInnes (he wrote the book on turbo's) told me that the L/M 180 produced a true 160 hp at the flywheel. Hugh's company (TRW) did all the development work on the Corvair turbo set-up for GM.
>
> Tom Keosababian

Its only true that an FI engine and a carbed engine will make the same power at the same boost if they have the same timing and the inlet air is at the same temperature, and generally, because of severe throttling losses, fuel air mixture differences cylinder to cylinder and timing advance compromises to cover up those issues, they will NOT make the same power. Its more like they "can" make the same power.
One thing about the turbo graph, remember, it has a 3.89:1 differential, so there's a lot of torque multiplication... it is at 20psi of boost with a 3.1 liter engine, and I seem to remember reading about one of your cars being tested in the late 60's at a dragstrip, and from the 1/4 mile times they estimated your car at being in the 350hp range. Doesnt sound that unreasonable to me!

------------------------------------

Kevin Nash
Friday Harbor Washington
63 Spyder, Daily driver, EFI read about my project here: [corvaircenter.com]
first test start on EFI here:[www.youtube.com]
first official EFI boost test here:[www.youtube.com]
My new fan! [corvaircenter.com]
engine less 62 Spyder
Canadian 64 Monza Parts car



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Re: Actual HP numbers
Posted by: American Mel ()
Date: November 15, 2020 08:15PM

tomkeo Wrote:
-------------------------------------------------------
> Here's the math. HP = Torque X RPM (divided by) 5250. Looking at the dyno curve Dave posted, you would need OVER 500 lb/ft of torque at 3500 rpm in order to produce 350 HP at that speed as shown on the graph. Not very likely, even with an E-flow compressor. Matt is right, at wide open throttle and the same boost level, there will be very little difference in HP between FI and carburetor.
> As far a true horse power rating, Hugh MacInnes (he wrote the book on turbo's) told me that the L/M 180 produced a true 160 hp at the flywheel. Hugh's company (TRW) did all the development work on the Corvair turbo set-up for GM.
>
> Tom Keosababian


Thanks Tom.
so, if we minus 20% for drive-train losses, we should be seeing 128 on the ground, not 99.
Those numbers just didn't add up!
50% loss is just ridiculous!
Yes, I knew that 35 on an 80hp was not correct, I was just trying to make a point.
180, 99 on the ground. eye rolling smiley hot smiley

-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
WA. state, 1 mile south of the Canadian border,
I am not at the end of the world, but you can see it from here.
Have; '66 Monza Coupe - 140, 4-spd. Daily driver beater
'67 Monza Vert. - 140, 4-spd. Daily driver beater
'67 A/C Moredoor Monza
Have had; '61 Monza coupe, 80hp, PG
'62 Monza Wagon, 4spd.
'63 Spyder,
'65 Corsa
.
non-vair
'04 Dodge Cummins Quad Dually, approaching 400K
'03 Honda Del Sol
17'Terry

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Re: Actual HP numbers
Posted by: MattNall ()
Date: November 15, 2020 09:44PM

Amel, it was a DOG and I told him so!!! GG

Also, he never told us what his timing curve was!

MODERATOR
Sea Mountain, between Charleston Harbor and Coos Bay! SW Oregon Coast
Click HERE for My Website...Click HERE for My TechPages!
..............................110-PG.................................................Webered-Turbo




Edited 2 time(s). Last edit at 11/16/2020 08:42AM by MattNall.

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Re: Actual HP numbers
Posted by: jjohnsonjo ()
Date: November 16, 2020 01:43PM

Going from "memory" as I don't remember where I read it. Corvairs were closer to correct hp than other cars of the era. Most were tested with no muffler, fan or air cleaner. The turbo Corvair was the truest HP, because the muffler, fan, alternator and air cleaner/carb were all required to test it as a system. If someone has solid info that this is not correct, please post it and correct my aging brain.

J.O.

65 Corsa Turbo Vert
79 Honda XL 500S
69 Honda CL 160 D
2010 BMW F 650 GS
2003 Bounder 36D
2013 KIA Optima SX turbo-AKA ZIPPY (wife,s car)
69 Newport Holiday Sailboat
Baja 150 dune buggy cart
Coleman HS 500 UTV
2016 KIA Sorento SXL Turbo

Bethlehem,Pa


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Re: Actual HP numbers
Posted by: joelsplace ()
Date: November 16, 2020 03:53PM

I've read that actual crank HP on a 180 is 186. I can't remember where I saw that.

Joel
Northlake, TX
5 Ultravans, 113 Corvairs and counting...

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Re: Actual HP numbers
Posted by: jjohnsonjo ()
Date: November 16, 2020 03:59PM

joelsplace Wrote:
-------------------------------------------------------
> I've read that actual crank HP on a 180 is 186. I can't remember where I saw that.

It may have been in one of Bob Helts books, where at a lower ambient temp the HP correction was above 180

J.O.

65 Corsa Turbo Vert
79 Honda XL 500S
69 Honda CL 160 D
2010 BMW F 650 GS
2003 Bounder 36D
2013 KIA Optima SX turbo-AKA ZIPPY (wife,s car)
69 Newport Holiday Sailboat
Baja 150 dune buggy cart
Coleman HS 500 UTV
2016 KIA Sorento SXL Turbo

Bethlehem,Pa


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Re: Actual HP numbers
Posted by: vairmech ()
Date: November 16, 2020 05:11PM

I'm surprised no one has put this up yet. All I can say is dream on everyone!

[youtu.be]

[youtu.be]

You can watch history being made.

Ken Hand
Handy Car Care
248 613 8586

Vairmech@aol.com

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Re: Actual HP numbers
Posted by: tomkeo ()
Date: November 16, 2020 05:15PM

Kevin Nash wrote:

<One thing about the turbo graph, remember, it has a 3.89:1 differential, so there's a lot of torque multiplication... it is at 20psi of boost with a 3.1 liter engine, and I seem to remember reading about one of your cars being tested in the late 60's at a dragstrip, and from the 1/4 mile times they estimated your car at being in the 350hp range. Doesnt sound that unreasonable to me!>

Making 350 hp at 6500 rpm is not the same thing as making the same hp at 3500 rpm. The 180 stock turbo produces 265 lb/ft or torque at 3200 rpm. Using the formula I posted earlier, that represents 160 hp. In order to double the hp at that rpm, you would have to double the torque (530 lb/ft)! It has nothing to do with gear ratios. If you could produce 265 lb/ft of torque at 7000 rpm, you would have 350 hp. It would be impossible for a Corvair engine to produce 350 hp at 3500 rpm on gasoline. The BMEP would be so far off the chart, the engine would detonate as soon as the turbo spooled up.

Tom Keosababian

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Re: Actual HP numbers
Posted by: MattNall ()
Date: November 16, 2020 05:17PM

Ken that's old news! like 8 years old!! GG

MODERATOR
Sea Mountain, between Charleston Harbor and Coos Bay! SW Oregon Coast
Click HERE for My Website...Click HERE for My TechPages!
..............................110-PG.................................................Webered-Turbo




Edited 1 time(s). Last edit at 11/16/2020 05:19PM by MattNall.

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Re: Actual HP numbers
Posted by: alphasud ()
Date: November 16, 2020 06:31PM

I called my local area and got 2 shops that perform chassis dyno testing. One guy is several months out and the other didn’t return my call. Will keep trying and hopefully the weather holds out to get in before I’m down till spring.

David North Idaho
1965 Corsa Turbo converted to 140
1971 Super Beetle with 2.5L Subaru engine
1965 Corsa mid engine project
1973 Mercedes 280 project

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Re: Actual HP numbers
Posted by: 63turbo ()
Date: November 16, 2020 08:40PM

tomkeo Wrote:
-------------------------------------------------------

>
> Making 350 hp at 6500 rpm is not the same thing as making the same hp at 3500 rpm. The 180 stock turbo produces 265 lb/ft or torque at 3200 rpm. Using the formula I posted earlier, that represents 160 hp. In order to double the hp at that rpm, you would have to double the torque (530 lb/ft)! It has nothing to do with gear ratios. If you could produce 265 lb/ft of torque at 7000 rpm, you would have 350 hp. It would be impossible for a Corvair engine to produce 350 hp at 3500 rpm on gasoline. The BMEP would be so far off the chart, the engine would detonate as soon as the turbo spooled up.
>
> Tom Keosababian

This is why the whole concept of horsepower was developed, to eliminate the effects of gear ratio!! torque is a measure of work, horsepower is a measure of how fast the work can be done. It is very easy to produce 500 or a 1000 ft-ls of torque by me just by giving me a long enough bar and a short enough pivot... before the concept of hp was developed, groups would try and impress people with their devices that could lift incredible weights but of course took a lot longer to lift the same weight than a competing device that was just bigger, and didn't have any gear reduction device.
Yes you are absolutely correct, it is really tough on a Corvair engine to make lots of boost at a low rpm... I know a guy that managed to hit 20psi at some low engine rpm less than what that the dyno showed, he bent a bunch of rods, and the engine only lasted 5000 miles. His was a 140 based engine with a blow through EFI but stock displacement.
Its a lot more about head flow, engine size and turbo set-up and how hard its loaded as to how quick it can "change its flow as to wether or not it could actually get to that boost level at a relatively low rpm, and it is entirely possible. Point being you cant dismiss the hp numbers because of the torque calculation. One of the reasons (among many!) that the 180hp engine only makes 180 gross and 160 net is because of the severely limited head flow. 95hp heads only flow around 61 cfm on the intake, 110 heads flow 92 cfm, 140 heads flow around 145, and amazingly can flow as much as 238 when properly ported, at least that's what mine did on a flow bench. Assuming that the rest of the intake was modded enough to keep up with intake ports that can flow 238cfm, then the engine should be able to gain as much power as the % increase in flow, because flow and hp are proportional to one another. I dont know the flow for stock turbo heads but lets just assume they flow at least as well as the 110's- to go from 92 to 238 is a 158% increase in head flow, and so this 160 hp net engine at 10psi would then make 253hp. Going from 2.7 liters to 3.1 liters is a 14.8% increase in power so now we are up to 290hp, at only 10psi of boost! its hard to see how it "cant" make 71 more hp at double the boost.
Modern turbo tech and EFI has done wonders for our engines, esp. when race gas, water injection, competent head porters, and roller cams and proper gearing are employed, those kind of numbers are being put up, but are not "street' cars. That dyno chart isnt the first time I've heard of numbers like that for Corvair engines. One other engine that I know of "like that" makes 280 at the rear wheels on race gas, and water/methonal at only 18psi boost and is a stock displacement engine, he's getting all that boost near "instantly" at around 4k for the engine... he would be around 322 with a 3.1 liter engine so no not a stretch in the slightest that only another 38hp couldnt be found by a couple more psi of boost and a slightly different tune... intermittent boost and power being easier to achieve and more safe than having to continously maintain that power for minutes or hours at a time. The other thing, we dont know how is how it is being tested... they could have deleted the fan and alternator for this.

------------------------------------

Kevin Nash
Friday Harbor Washington
63 Spyder, Daily driver, EFI read about my project here: [corvaircenter.com]
first test start on EFI here:[www.youtube.com]
first official EFI boost test here:[www.youtube.com]
My new fan! [corvaircenter.com]
engine less 62 Spyder
Canadian 64 Monza Parts car



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Re: Actual HP numbers
Posted by: MattNall ()
Date: November 16, 2020 09:00PM

Kevin!! I sure hope you used "Text to speech" today.. you've written a book!!! GGG

MODERATOR
Sea Mountain, between Charleston Harbor and Coos Bay! SW Oregon Coast
Click HERE for My Website...Click HERE for My TechPages!
..............................110-PG.................................................Webered-Turbo

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Re: Actual HP numbers
Posted by: alphasud ()
Date: November 16, 2020 09:24PM

I can’t imagine any Corvair bottom end surviving long term with that type of power. 4 main bearings ain’t much and the case halves aren’t pinned but I’m sure the builders are using special case bolts to act as pins. Still the bottom ends don’t look that stout to me.

David North Idaho
1965 Corsa Turbo converted to 140
1971 Super Beetle with 2.5L Subaru engine
1965 Corsa mid engine project
1973 Mercedes 280 project

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Re: Actual HP numbers
Posted by: MattNall ()
Date: November 16, 2020 09:47PM

TomKeo had to run 5 milesto reach 173.1 avg. at Bonneville. approx. 400 hp.

MODERATOR
Sea Mountain, between Charleston Harbor and Coos Bay! SW Oregon Coast
Click HERE for My Website...Click HERE for My TechPages!
..............................110-PG.................................................Webered-Turbo

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Re: Actual HP numbers
Posted by: 63turbo ()
Date: November 16, 2020 10:33PM

Yes, and there's sandrails that are up around 650hp, but its only for a few seconds. Boost can definitely kill engines quick at that level when something goes wrong! One guy I heard about had his block more or less explode!

------------------------------------

Kevin Nash
Friday Harbor Washington
63 Spyder, Daily driver, EFI read about my project here: [corvaircenter.com]
first test start on EFI here:[www.youtube.com]
first official EFI boost test here:[www.youtube.com]
My new fan! [corvaircenter.com]
engine less 62 Spyder
Canadian 64 Monza Parts car



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Re: Actual HP numbers
Posted by: vairmech ()
Date: November 17, 2020 04:51AM

MattNall Wrote:
-------------------------------------------------------
> Ken that's old news! like 8 years old!! GG
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

Yeah, but you are talking turbo and this is normally aspirated!

Ken Hand
Handy Car Care
248 613 8586

Vairmech@aol.com

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Re: Actual HP numbers
Posted by: dryenko ()
Date: November 17, 2020 05:54AM

Let us be clear here.
As many of us racers have found, a crank originally designed for 80 HP can in no way last very long when asked to survive 200+ HP or 300 lb-ft or Torque.
They usually beak at the #3 main or the 5th or 6th rod journal.
Laboratory analysis clear shows fatigue failure fron the journal radius.
Or lack thereoff, as in the 164 C crank made from the 145 CI forging.
Prudence demands changing out a Yenko race engine well prepared crankshaft about ever 8-10 weekends.
Better material cranks are available for around $2500.
But even those cranks have a limited fatigue life.
So maybe 20-25 weekend cycles.
If the change out is not done, you can end up with $10K pile of junk.
Ask me how I know.
As always, Your ideas and opinions may vary.
BC

Bob C aka Dryenko
Dobson, NC 27017

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Re: Actual HP numbers
Posted by: joelsplace ()
Date: November 17, 2020 06:17AM

So would that be an argument for using a 145 if you wanted it to last longer? The crank should be stronger and the torque would be at a higher RPM.

Joel
Northlake, TX
5 Ultravans, 113 Corvairs and counting...

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Re: Actual HP numbers
Posted by: 63turbo ()
Date: November 18, 2020 09:31PM

joelsplace Wrote:
-------------------------------------------------------
> So would that be an argument for using a 145 if you wanted it to last longer? The crank should be stronger and the torque would be at a higher RPM.

Yes, it absolutely is a good idea to use a 145 crank, because of the enormous increase in crankshaft overlap. Here's a comparison in cross sectional area between the late crank and early crank... its something like a 62% increase in area! If someone were to increase the bore size to 94mm, theres a 2% increase in displacement so theres no torque loss, and the heads do flow better with the larger pistons. If the combustion chambers are worked on to "unshroud" the valves enough to fit the new bore size the heads might very well have enough of a VE increase to make up for the reduced piston speed of the shorter stroke, and should be able to take high rpms much better. My next engine is going to use 92mm cylinders with a near virgin short stroke Spyder crank with ported 140 heads. Ought to be quite a hoot!

------------------------------------

Kevin Nash
Friday Harbor Washington
63 Spyder, Daily driver, EFI read about my project here: [corvaircenter.com]
first test start on EFI here:[www.youtube.com]
first official EFI boost test here:[www.youtube.com]
My new fan! [corvaircenter.com]
engine less 62 Spyder
Canadian 64 Monza Parts car



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Re: Actual HP numbers
Posted by: alphasud ()
Date: November 21, 2020 04:31PM

Well the guy that runs the dyno shop calle me back and a was given an appointment Saturday morning. Fist I will describe what I was testing. 65 Corsa 140 engine is stock with exception to a Sprint style exhaust. Timing set to 16BTDC and mechanical advance was verified. Carbs were cleaned and new kits installed last year. Carbs were recently checked for balance and wide open throttle. I ended up with 73HP at the wheels and a peak torque of 116ft/pnds. The HP peak was at 4300 rpm’s. and after that things started falling off. This at least serves as a good baseline as I intend to run at the same dyno when I get the new engine built and installed. Also take note of the A/F ratio’s during the run. It’s definitely not starving and if anything a slight correction could be made to lessen the high speed enrichment as it dipped to 11.5:1.
All in all a fun exercise to do and a $50 well spent.

David North Idaho
1965 Corsa Turbo converted to 140
1971 Super Beetle with 2.5L Subaru engine
1965 Corsa mid engine project
1973 Mercedes 280 project

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