140 hop up help needed

[Trip]

Hello folks,

I'm hoping for some feedback and evaluation of the hot-rodded 140 in my Corsa coupe.

My 140 has forged pistons, a 280 Isky Cam, Pertronix 2 and flamethrower coil, mildly ported heads with the step machined out, mildly modded carbs, and high flow mufflers on stock manifolds and down pipes. I briefly installed headers and did not notice any real difference. As it is I can barely out run my brother in his 5spd Honda Fit sport from 0-60 or 0-70. His car is supposed to run 10.1 seconds 0-60 and a 17.5 second quarter mile so that's about where I am. This is in my 66' Corsa coupe with the 4 speed. My tires are taller than stock changing the effective gear ratio a bit. I had Bryan Blackwell drive my car in detroit to see if he thought it was running like it should given the build.. he said it felt pretty good but that was of course seat of the pants, not measured numbers.

I won't be able to answer a lot of the questions some of you might ask. I started with an engine that it turned out someone else had built for autocross and a lot of the work was already done. When I took it apart I found it was at max bore, had the forged pistons, 280 Isky cam etc. I took the heads to the Corvair ranch to have deep valve seats and porting done (as well as new springs etc.) and Brett told me afterward that the porting had pretty much already been done to the extent that is possible without cutting the heads open for access. Also the step had already been machined out.

I took the engine down most of the way but once I discovered the 280 Isky cam I stopped short of splitting the block (I had intended to put a 270 in). The engine showed no signs of wear so it seemed the previous build had few miles on it. I cleaned everything up and put it back together.

I had my carbs done by Grant Wolf. He did a full rebuild with standard performance mods on all four. Someone had tinkered with modding the carbs before but he said they did a lousy job of it so he fixed them up for me.

I run premium fuel but my timing might not be advanced as far as might be optimal because I have to watch out for pinging. I think my timing is set right where it is supposed to be for a stock 140 by the book.

When making suggestions please take the following into consideration: This car is driven daily about 8 months per year and occasionally goes on long road trips to Corvair events. Also I'm on a very tight budget. The car sounds exactly the way I want it to but it doesn't have the performance to back it up.

Thanks in advance for your time guys!

[flat6_musik]

Hey Grymm.....sounds like you've got a pretty cool setup to start with.....at least it's fresh and got a good cam in it already. I'm no big expert and I also am not exactly sure how fast you can expect a 140 to be. I would keep the headers on though, I mean, why not? Gawd, compared to those stock exhaust logs, that's gotta give a decent boost in H.P. even though you may not have really felt it "seat of the pants". Maybe you could do some 0-60 timing with a friend or take 'er out to a dragstrip sometime. Another thing I personally am fond of it bumping the initial timing a bit and disconnecting the vacuum advance. Of course, do it incrementally so it won't ping. Hotter cams like that Isky 280 will tend to reduce the chance of the pinging in the lower RPM anyway, because they "bleed off" some cylinder pressure from the overlap.

Also, look for little ways to pick up power.......good low-restriction air filters, making sure you're getting full throttle opening, maybe even a lighter oil! I hope your tires aren't THAT tall! Good luck!

[martyscarr]

Ray sez: "The car sounds exactly the way I want it to but it doesn't have the performance to back it up."

Ray-

Okay, so more performance is desired, as in quicker 0-60 times, is this right? If so, you can do the following:

Change to a smaller tire - or change to a 3.89 or 4.11 ring and pinion. This will make your car noticeably quicker. Changing to a smaller tire/wheel combo is pretty cheap. Downside is it's not much fun if you do a lot of freeway driving.

Put the headers back on - they work well with ported heads and a 280 cam, and the results can be measured. If you're not documenting performance changes with a G-Tech (or similar) you are only guessing. Seat of the pants is BS.

Install an Megajolt ignition and have the car dyno tuned with a hub dyno (like Dynapack). There are measurable gains to be made with a programmable ignition and dyno tuning will maximise the HP gain.

Go for further head mods - not cheap but that is where more power can be gained. Porting mods inside the log manifold are good for 20 HP according to Warren LeVeque. Beyond that, tri ported heads, Webers or EFI will get you further gains. How fast do you want to spend, I mean go?

More cubes. 3.1 engines are getting pretty common, and they provide quite a bit of extra torque, which is what you're after. There are several vendors that do this mod, to read about the process go to Sandsports Magazine article on Kent Sullivan's site here: http://corvairkid.com/mm01.htm

Turbocharging will get you more performance as well.......

Marty Scarr

[cvair4life]

I'm curious what your times are if you could get some real accurate 0-60, 1/8, and 1/4 mile times it would be interesting to compare them to my stock 140. I haven't timed it yet either but that "time" will come :) I'm also going to time my 110 to see how it performs... if I can ever get the popcorn machine out of the pipes.... grrrrrrrrrr

[Trip]

Got some answers for you guys, thanks for the replies =)

First off it's important to know (though most of you will disapprove!) that this car is mostly for daily driving and cruise-ins... so looks, sound, and reliability are very high on the list of priorities. In that respect I'm happy with the car now. On the other hand I feel like with the mods I invested in I should get decent performance and I don't. Also it'd be nice to be able to brag that she goes as good as she looks and sounds, currently I'm ashamed of my performance for the following reason:

(Zach) I'm fairly certain that with all my mods the car isn't any faster from 0-70mph than it was when it came out of the factory stock =(... that is shameful for a car that looks and sounds beefed up.. and after all I've put into it.

I couldn't get the headers to seal and I drive the car daily 3/4 of the year so I need heat... I gave up and got rid of the headers, so I no longer own them. I really don't think that my exhaust is what is holding me back right now. According to my rough stopwatch runs near my house there was little or no difference between running the headers and stock manifolds. I used a rolling start of 10mph as measured by my GPS... gunned it as I passed a certain landmark and ran it as fast as I could to another landmark further up the road. I'm not sure of the distance but I was right around 70mph when I hit that landmark both with and without the headers. I did three runs with each setup on the same stretch with the same start and end points.

The difference between headers and stock 140 logs was less than the variance between my crudely measured runs =(. I had really hoped those headers would unleash the beast!

Also I wanted to mention I've long wanted to try a Gtech-Pro for getting rough estimates of performance differences when I make changes. I wouldn't expect the accurate numbers out of if that they claim but I thought maybe it would be good for doing before and after runs? Anyone ever try one? If it works it would be great to use it for tinkering with timing etc... and to check and see if performance mods (like those headers) payed off.

Ray R.

P.S.- I really feel like I'm beating up my Corsa when I do launches from a standing start so I have a tendency to use rolling starts when I can... Maybe I'm just getting old! =P

[Stinger Motorsports]

The Headers didn't help much b/c the problem with the exhaust lies in the port and tube design. The exhaust is required to make a 90 deg bend as it hts the port then it is restricted by the tube having a notch in it for clearance of the head stud.

The trick thing to do is have the heads angle ported. this will require removal of the head and some costly machine work (which my shop offers) The factory exhaust ports are removed and the holes opened up to allow larger diameter tubes. Also while this is being done the port gets more radius in it's design allowing more flow.

My angle port jobs come with a one piece exhaust flange with mating header flanges. These flanges seal and you can creatively cut lower shrouds to gain back some heat without worry of exhaust leaks.

The other thing to do is get a custom ground camshaft. Corvair engines are exhaust challenged and need longer dur on the exhaust cam lobe.

None of these can be done without a tear down but they will get you the results your looking for.

From the sounds of your engine there isn't going to be much of anything you can do to gain a noticable increase by just bolting something onto the engine.

About my only suggestion for a bolt on is K+N individual air filters. They make one which has a velocity stack built into it, these along with smoothing out the carb tops can greatly increase flow.


Good luck with your project.
David C
Owner
Stinger Motorsports

[flat6_musik]

One thing I was going to mention is that.....I wouldn't be surprised if that Isky 280 is maybe a bit too hardcore for your mostly-street-driven car. Lack of low-end torque possibly. I'll bet a 270 would be better. I think Scott likes his IIRC.... Although yeah, I do remember, Grymm, that the budget is the name of the game here. That might be also why you hafta slip it and launch it like a mad dog.....it may be a little soft on the low end. Just really hard to believe the headers wouldn't help.....and if they DON'T help, I'd think maybe that's an overly lean/rich problem.

[atwistedgrip]

Lose weight... Lighten your car. One of my favorite ways is alloy wheels.
Also try smaller diameter tires, it'll give you more off the line performance while the 280 cam is good for top end.

[miniman82]

Sounds to me like he's already taken the engine as far as it can go in naturally aspirated form, time to start cheatin' if you ask me!

[Trip]

One thing I was going to mention is that.....I wouldn't be surprised if that Isky 280 is maybe a bit too hardcore for your mostly-street-driven car. Lack of low-end torque possibly. I'll bet a 270 would be better. I think Scott likes his IIRC.... Although yeah, I do remember, Grymm, that the budget is the name of the game here. That might be also why you hafta slip it and launch it like a mad dog.....it may be a little soft on the low end. Just really hard to believe the headers wouldn't help.....and if they DON'T help, I'd think maybe that's an overly lean/rich problem.

I actually originally bought an Isky 270 =). When I tore the engine down I found the 280 already installed, so I sold the 270 to someone here on VV (this was maybe 5 years ago!).

I actually would prefer low end torque, but I LOVE that lopey idle!!!!

[Trip]

Sounds to me like he's already taken the engine as far as it can go in naturally aspirated form, time to start cheatin' if you ask me!

I'd love to try a turbo, I recently put a lot of thought into starting to put one together but I've since decided that I need to focus on more important Vair' projects before I get into that. I want to restore the underside of the 66' on a rotisserie for longevity and put all new bushings in it, I still have a lot of things that should be done on the 63' (reseal the engine, redo the front suspension and steering, properly fix the rusty floor that I fiberglassed, patch the trunk floor, install new weatherstripping, get a decent muffler, and more), and I have to finish putting the 65' together (now that would be a long list!). I guess I've got to curb my enthusiasm a bit and dig in on the less fun projects.

On the bright side I think I've decided to slow down a bit on the 65' project and keep it at least for a while instead of hurrying up to finish it so I can sell it. I decided by the time I recover the money I'd have to spend to finish it the remainder would hardly be worth giving up my excellent 2nd 140 drive train. I think the 65' might become my winter car plus provide a backup if I break the 66'.

[UNSAFE]

The trick thing to do is have the heads angle ported. this will require removal of the head and some costly machine work (which my shop offers) The factory exhaust ports are removed and the holes opened up to allow larger diameter tubes. Also while this is being done the port gets more radius in it's design allowing more flow.

I think any performance engine work should start with the heads . The angle tube exhaust makes a major difference. The stock tubes neck down so much to clear the pushrod tubes that you can barely get your finger in them.

As far as "Cheatin" -- don't do it Grymm -- you won't be able to sleep at night

Here's a pic of angle tube exhaust for you that aren't familiar with them . These heads have been ported and modified for Weber carbs.

[Trip]

I learned about the angle port mod last year when I was trying to get a used pair of headers to seal up (unsuccesfully). I wish I had known about it before I paid to get my heads done.... I kinda feel like I got ripped off on that deal now. A certain Corvair shop was recommended to me for my head work (by a guy I met at a semi-local Corvair meet) and I paid them $900 (4 or 5 years ago?) to clean the carboned up heads, install deep seats (that they guaranteed would never drop), and clean up the ports as best they could. I'm pretty sure I got new springs too. I was told later (by the shop) that the heads already had been cleaned up about as much as is possible without cutting them open and the step had already been milled out. I also wasn't thrilled with the fact that there were gouges around the seats that could possibly result in hot spots... come to think of it maybe that has something to do with the slight ping that I (think) I hear if I try to advance the timing at all. The ping is so light it could be imaginary and I'm also told that I need to use higher RPM when driving around the hilly area I reside in.

Here is a pic of my heads after getting them back from the shop:

I'd really like to do the triple Weber's or maybe fuel injection but again I need to hold off until I get my other project cars under control.

In reality I quickly get swept up in the excitement as soon as I start talking about the possibilities but it's not really a big enough priority that I want to spend a ton of money on it. I guess I'm getting old cause installing AC is gonna come long before a whole new engine build, webers, or fuel injection .

For now I just need to make what I've got work as well as possible. I'm hoping that the car will be a bit quicker this year with proper carb balance and better adjusted linkages . I'm pretty sure I didn't get it right last year. I'd also LOVE to find out if my distributor curve is wonky or something, guess I'd better pull it out and get the numbers off it while I'm working on it this coming month.

[Trip]

Alrighty, I've settled on the "next step" for me. I've found a way to rationalize myself into paying for some further improvements!

I have a good 2nd 140 engine that was rebuilt by the prior owner. It came in my 66' Corsa (the hot rod 140 in the 66' came with my as of yet unfinished 65') and was rebuilt by the prior owner but I have no way to know to what extent.

The only thing I do know is that it ran beautifully and more or less didn't leak oil. I also know that it had one of those crappy silver colored pilot bushings that was wallowed out badly when I got it.

This engine is currently in my 65' Corsa which I recently decided I'm going to keep for a while and use as a backup/winter car.

Since I don't know if anything was done to prevent a dropped valve seat on the heads in that engine it gives me an excuse to save up to get another set of 140 heads done!!!! After all I don't want to risk a dropped seat wrecking my perfectly good stock 140 right??!!! Once I get those heads done I can put them on the hot rod 140 and put the hot rod 140's current heads (pictured above) onto the stock 140 and I'll be all set.

So the question is: About what do you think it should cost me to have an angle port job done on a good set of 140 heads along with deep seats and performance improvements to the extent a minimal budget will allow (basic porting, step removal etc.)? Anyone want to suggest a good Corvair engine guy to do the heads? It will take a while but I need to know how much $ I need to save up =). Also need to find out how much the headers for the angle ported heads are gonna cost me =).

While I'm at it maybe I should get the heads set up for webers, or fuel injection, or a turbo.... or a fuel injected turbo, or a big bore 3.1 fuel injected turbo, or a reverse rotation big bore 3.1 with a roots blower and fuel injection.............

[martyscarr]

Ray wants to know:
"So the question is: About what do you think it should cost me to have an angle port job done on a good set of 140 heads along with deep seats and performance improvements to the extent a minimal budget will allow (basic porting, step removal etc.)? Anyone want to suggest a good Corvair engine guy to do the heads? It will take a while but I need to know how much $ I need to save up =). Also need to find out how much the headers for the angle ported heads are gonna cost me =). "

David Clemens (Stinger Motorsports) 540-204-0917 or Michael LeVeque (Levair Performance Products) 765-617-9307

Either one will take good care of you.

Marty Scarr

[flat6_musik]

I wanna know too.....I'm super curious! *tax return?* :)