Motor build

[Mike D]

i just purchased a 66 corvair a ton of upgrades done to it it was non running because it had been sitting, however i just got it running today, and all seams well.

My question, is how much HP do you think the motor makes with the mods listed below by the PO in his for sale Add


Enigine( forged light wieght pistons, molly rings, all jugs mechined and honed standard bore, rods sent out, lightened shot piened and magnufluxed, new bearings, new cam its a 280 grindwith high lift autocross racing/compitition cam, the last of the streatable cams you can put in this engine, new cam and crank gears, high capacity oil pump, high capacity finned/baffeled valve covers and oil pan alluminum, racing headers, racing quad port manifold with 390 nasscar double pump custom carb made by holly taylored for this engines needs, new liflers adjusted to engine, custom lifters and rods, triple ground valves and nylon valve seals, ported and pollished, modern oil filter insalled, crane cams electronic ignition with 60k coil and taylor 409 Hemi wires, has the big heads, bigest ones chevy made for the crvairs, new fuel pump, altinator, starter, pullies, magnisium fan, clarks fan belt, lightened and ballenced race fly wheel.

[flat6_musik]

I'll just guess and say 200.

[UNSAFE]

Not wanting to rain on your parade but those mods are likely to make less than 10% additional HP if all is well tuned.

A 140 HP only really made about 100 hp so you could optimistically expect about an extra 10 HP.

It takes an awful lot to get an honest 200 hp out of a Vair.

[Vairforce1]

Is this the convert that was listed on the Boston Craigslist? If so, I think you have a pretty decent base of a car to work with. IIRC, there were a lot of suspension uprades done to this car as well. Should be a good project!

Dave

[Mike D]

yep, this was the one on CL in boston, it has a TON of suspension upgrades. to me a good chasssis is worth way more than a straight liner.

the owner wanted to claim it made 220-240hp, although that sounded high to me,,

when i get it running straight, ill put it on a dyno to see what it makes

here are a few photos i havent cleaned it yet, just been focusing on getting it running,

[Corvair.crazy]

Looks pretty nice! A double pumper holley, thats seems like a lot of carburation. Does it have good throttle response?

[Mike D]

yep terrific response,

its only a 390cfm,, so its much smaller than ones that are on v8s (most 350s use something in the 600cfm ballpark) i was told that it was custom taylored for the motor.

[flat6_musik]

Not wanting to rain on your parade but those mods are likely to make less than 10% additional HP if all is well tuned.

A 140 HP only really made about 100 hp so you could optimistically expect about an extra 10 HP.

It takes an awful lot to get an honest 200 hp out of a Vair.

You may be right, but.....I'm going to disagree. If what you're saying is true, then this specific motor combo is only going to put out 110 H.P. @ 6000 RPM?! (we ARE talking @ the flywheel, right?) I think that would border on pathetic! I don't have any dyno experience with these motors, but SBC's have been capable of 1 H.P. per cubic in since the 50's through cast iron exhaust manifolds! Hard not to imagine a 1 H.P. per cube ability with a hot cam and headers in a 'vair. Most of what was mentioned on that engine build sounds more like a stock-ish 140 with a hot cam, headers, forged pistons and a good amount of durability upgrades. I was actually a hair away from typing 180~200 H.P. originally.

Unsafe, your car is capable of mid-14's isn't it? What would you say your setup is putting out? It's got to be fairly substantial amount, being as 'vairs aren't THAT lightweight.

[UNSAFE]

You may be right, but.....I'm going to disagree

Mark wright's 3.1 efi motor made about 190 hp on a dyno. Roger R's modified turbo was about 200. Michael Leveque's race motor was about 180 , Duane Cartwright's EFI car made 190.
I beat Roger in the Qtr but he was coming on strong at the end with a faster trap speed than my car. He is likely making more power than I am .

I always wanted to think that I was getting 250 hp but more realistically it's probably about 190 hp. This is with 190 cubes , ported heads with angle exhaust ,bigger cam , headers , etc , etc.

Using a hp calculator based on 1/4 mile times my car is at 176 hp

The stock engine test paper lists the 140 at about 100 hp so I'm sticking by my guns

A vair that can do the Qtr in 16.5 at 85 mph is making 124 hp. That's still as fast or faster than what most Corvairs can do.

[martyscarr]

Here are some dyno results of some of the above mentioned Corvair engines: http://corvaircenter.com/phorum/read.ph ... msg-471830

"It takes an awful lot to get an honest 200 hp out of a Vair."

Very true. Without a lot of head work on the intake (removing the stock manifold for individual runners) and the exhaust (install slant tubes) you're going to be limited in your gains.

I'll bet Mike D's car is quicker/faster than a stock 140, but nowhere near 200 flywheel HP.

Marty Scarr

Mike D

[flat6_musik]

That's pretty sad then. My old chevy's 4.3 V-6 was factory-rated @ 200 H.P. I know that's quite a jump in displacement over a 'vair, but I would think that throwing "everything in the book" at these engines would send them at least to 200. Do the cylinder heads "fall off" after 6000 RPM?

[flat6_musik]

Here are some dyno results of some of the above mentioned Corvair engines: http://corvaircenter.com/phorum/read.ph ... msg-471830

"It takes an awful lot to get an honest 200 hp out of a Vair."
Very true. Without removing the stock manifold on the head you're going to be limited in your gains.

I'll bet Mike D's car is quicker/faster than a stock 140, but nowhere near 200 flywheel HP.

Marty Scarr

Mike D

Well, wait a minute. On that Corvair Center's thread, Matt Nall's post show's Mark Wright's 3.1 triple-barreled run @ 270 H.P.! I'm confused.

I don't know about the others.....that Bill Elliot's turbo 2.6 putting out 203 H.P. and 220 Tq?! Makes me wonder how much boost he was running. I just don't see how that's possible. My son's Nissan 240SX's 2.4 liter 4-cylinder turbo puts out 270 AT THE WHEELS!.....running close to about 20 lbs. of boost.

Seems like I read that Starr Cooke guy stated his Weber setups were good for 300 to 325 H.P., didn't he?

[cad-kid]

Looks like a great project there Mike!

[Mike D]

and here i was hoping for 180whp out of it,, sounds like ill be disapoinfted in performance when i finally get to drive it

I tune saabs for a living, Sadly ive become used to 300 wheel torque cars.. Still no complaints because its a super cool convertible. And it sounds it has that nice high compression sound, in an email he said he figures compression to be around 9.3/1

in other news, im reminded today as to why i hate carbs, a minor diaphram leak on the accelorator pump caused a minor fire,, Nothing damaged besides my sence of trust in simple machines

i also got all the vac lines sorted out,, its clear to me the PO didnt know how vacume leaks affect a cars performance

Carb rebuild kit, and exhaust parts have both been ordered

[Trip]

Not wanting to rain on your parade but those mods are likely to make less than 10% additional HP if all is well tuned.

A 140 HP only really made about 100 hp so you could optimistically expect about an extra 10 HP.

It takes an awful lot to get an honest 200 hp out of a Vair.

Exactly right,

(Edit: Don't be disheartened, you've got a very nice Corvair engine there!)


For starters when our cars were built they were rating engines by "developed horsepower" rather than "Certified Brake Horsepower".

Horsepower has become more and more honest over the years but especially in the 60's the ratings were often "optimistic" even if you factored in all the restrictions and loads that were not present when HP was measured.

Another thing worth noting... the Dyno's that are available to us presently for a fee are also generally misleading. Basically most customers will be unhappy if they pay to have the car dyno'd and get a disappointing result. In order to keep customers happier and make more money they have become semi-dishonest.

It's hard to say how much HP you are going to gain from those mods. An honest 200hp with a Corvair engine is a VERY lofty goal... not something us (by us I mean me) poor folks have much hope of achieving.

One thing worth noting, I have a 140 with similar mods but mine is .060 over and minus the lightened parts, single carb setup, and headers.

I too have the 280 Isky cam and the main thing it does (besides make idling sound AWESOME!!!) is move the power curve up to higher rpm. This means that if you really want to use this engine to it's full potential you need to rev it well past the factory red line. This is not something I'm comfortable doing, but once or twice a year I can't resist.

I'm very interested to compare my actual times from this engine to the more or less stock 140 I will have on the road soon. Hopefully I'll get some decent measurements for both.

[UNSAFE]

I'm confused.

Mark Wrights car is about as modified as you can get and still be driveable. He has spent years refining the car for autocross and he is a superb driver to boot . I'd never have a chance against his car in curvy track events but I'd still like a shot at him in a straight line

Bill Elliots car should be considered full race plus he adds a little hot air of his own

The ricers and other foreign cars usually have overhead twin cams and 4 or more valves per cylinder on much better flowing heads than the Corvair has . It usually takes the ported angle tube exhaust heads with I.R. induction to get a major boost in power. ---- Or "Cheatin"


Remember that those are dyno numbers and they were only making that much power for a brief time . They would not hold up very long at WOT in real life without breaking or melting .

Ray's dyno has a drag race Vair motor making 380 hp but only for 10 seconds or less at a time.

I've also heard tale of a sand drag motor making 500 hp but thats for less than 3 seconds at a time.

Seems like I read that Starr Cooke guy stated his Weber setups were good for 300 to 325 H.P., didn't he?

Starr claims a lot of things He's a really nice guy and I've bought some things from. I think what he is saying is that the weber set-up can support 300 hp without wheezing but the rest of the motor would have to be highly modified to need that much carb. Webers have replaceable venturii so you can make them flow just any cfm that you want them to. I'm running 40mm webers but the 46s would be capable of even more power even with the same size chokes.

and here i was hoping for 180whp out of it,, sounds like ill be disapoinfted in performance when i finally get to drive it

I sure wasn't infering that you'll be disappointed . I also have a Corvette with a 425 hp 383 stroker but my Vair is still more fun to rod around in.

I tune saabs for a living

I'd rather push a Corvair than drive a Saab

If you want a good idea about how a well tuned 140 with similar mods runs , and for Grymm some shots of the tachometer check out sdmonza on youtube. Here's one---