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Increase max RPM
Posted by: LeadFootLogan ()
Date: May 15, 2019 05:54AM

Recently I installed my Corsa dash in my 65 Corsa(Last owner had a Monza dash in there, don’t ask, I don’t know why either), and I noticed that the redline is around 5500rpms. I know it was 50s and 60s technology, but to me that seems low. My question is, what engine mods would I have to do to make the max RPMs higher? I’m looking for 6000rpm-6500rpm.

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Re: Increase max RPM
Posted by: Wagon Master ()
Date: May 15, 2019 06:03AM

What engine/cam combination do you have? Most stock grinds will be at the top of their power band about 5,000-5,500. Other than that,
1. Stinger electronic ignition.
2. After market valve springs.

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Re: Increase max RPM
Posted by: LeadFootLogan ()
Date: May 15, 2019 06:12AM

Currently I have a stock 140. I know eventually I will build the engine with an Isky 280 cam with more performance parts. Also the engine is sitting in my garage so I can’t do an out of car engine start

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Re: Increase max RPM
Posted by: Phil Dally ()
Date: May 15, 2019 07:05AM

Bring your checkbook and get ready to spend some money.

If it is a driver you're better of just leaving it stock.

140 engine runs really good in it's original configuration.

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Re: Increase max RPM
Posted by: BobV66Vair ()
Date: May 15, 2019 07:14AM

I am about to receive my Sedman engine. It will be limited to 6200 RPM and 220 HP. It is capable of much more but I want it to last for a while (no decent spare). Only about $9500 to achieve that number. it is a race only engine, not for street. RMP and power cost. How fast do you want to go?

Bob Vinnacombe
Sandy, Oregon
1965 Corsa 140 stock
1966 Monza Soon to be race car
1968 Monza Parts for now

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Re: Increase max RPM
Posted by: Phil Dally ()
Date: May 15, 2019 07:17AM

Ray did you right Bob...good price!! thumbs up

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Re: Increase max RPM
Posted by: LeadFootLogan ()
Date: May 15, 2019 07:20AM

Well, I want it to be decently fast for what it is. I would like to keep up with a stock civic Si. One day I’m going to get a Monza and do my version of a crown V8 swap. I’m going to get a C5 transaxle and a LS1 or whichever LS motor that runs the coolest on a stock radiator and mate them together. It will be a 400hp+ mid engine street car.

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Re: Increase max RPM
Posted by: Kyle_in_Mich ()
Date: May 15, 2019 07:32AM

Lifting the rev ceiling doesn't not necessarily make the car faster. I take it you want stoplight-to-stoplight performance? Maybe look at changing the differential gear, which will be cheaper than building a performance engine but will make the car accelerate quicker. Just lose some highway manners. It's all about balance.

CORSA Member
Traverse City,MI
Daily driver- Bicycle
Fun driver/project- 65 Corsa 140/4 speed

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Re: Increase max RPM
Posted by: LeadFootLogan ()
Date: May 15, 2019 07:37AM

Not really. As I have said on other threads, I’m building it for autocross and street usage. I know when I run my Isky 280 cam it has a power band range up to 6500

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Re: Increase max RPM
Posted by: MattNall ()
Date: May 15, 2019 07:57AM

LeadFootLogan Wrote:
-------------------------------------------------------
> the engine is sitting in my garage so I can’t do an out of car engine start

========================================================================

Wrong! Just like VW / Porsche... we don't need no stinking car body to run! GG

running on a table!

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: Increase max RPM
Posted by: chris ()
Date: May 15, 2019 10:23AM

Logan, to add to what Wagon Master said, one of the items (my understanding anyway) that can help you increase your RPM is installing new springs. Several vendors sell them and also have lightweight retainers. Ken Hand I know has stiffer springs and titanium retainers and others have used LS-style beehive springs/retainers (on my to-do list). Both Ken's and the LS retainers are about half the weight of stock retainers.

'65 Monza 4 door
4 speed
110hp
Gardner, KS

Heart of America Corvair Owners Association

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Re: Increase max RPM
Posted by: LeadFootLogan ()
Date: May 15, 2019 11:28AM

Thanks! I suppose there is a formula on my maximum RPM when I do the retainers and other modifications?

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Re: Increase max RPM
Posted by: MattNall ()
Date: May 15, 2019 11:54AM

Several times in the past I have just shimmed stock engine's valve springs with 0.040-0.060" shims.... check for coil bind...

These engines then rev'd to 6200 or better..

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: Increase max RPM
Posted by: Willt65 ()
Date: May 15, 2019 12:25PM

I have the 280 cam, 6 into 1 4 barrel, headers, stiff valve springs, igniter II ignition, etc.. . What redline should I expect the car to make power to, or what should it easily rev to? I'm tuning my carb and about to put NGK plugs into it. So far it seams to be around 5500, though I haven't had much time to play with it yet. Just curious what you all with experience would say my setup should be. Thanks

Will Teeter
Flintstone, MD
65 Corsa project

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Re: Increase max RPM
Posted by: Willt65 ()
Date: May 15, 2019 12:27PM

Sorry I hope I'm not hijacking this thread, don't mean to.

Will Teeter
Flintstone, MD
65 Corsa project

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Re: Increase max RPM
Posted by: solo2r ()
Date: May 15, 2019 12:43PM

I will say to put your $$$ in suspension and wheels/tires. Get to know the car with seat time then go for power. I started out this way with a 110 with a rotated 4x1 set up for a few years. Then built more power as time went on. My car still has pretty much the same suspension I started with . I had even put a 6 point roll
cage in before adding power!
Started out in SCCA ESP and am now in Street Mod
Here is a few pics the second day I had the car out with the 'chrome' engine and the car [pretty much] today with tri-ported FI 3.0

Attachments:


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Re: Increase max RPM
Posted by: LeadFootLogan ()
Date: May 15, 2019 01:06PM

The suspension is fully built. I disassembled it, had it powder coated, poly bushings, KONI adjustable shocks, Clark’s heavy duty springs, longer studs for the hubs, rebuilt hubs, Wilwood disc brake conversion(front and maybe rear), 4 piston caliper. I think it’s fair to say my suspension is good to go. I have my wheels picked out for racing and tires I’m still deciding, but I am looking at summer tires from Toyo and Firestone Firehawk Indy 500.

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Re: Increase max RPM
Posted by: CoCoCo ()
Date: May 15, 2019 01:26PM

At what point are there other limitations to the max rpm of a Corvair engine?
I get the breathing part, but are the block, crank, rods and pistons good to a known rpm level? Cylinder heads building heat or losing seats more readily after a certain rpm that can't be evacuated without changing the cooling setup?

Seems that lots of much higher power engines run the stock block, correct? How far do the crankshaft and connecting rods limit things, if at all?
Valvetrain has the usual upgrades, but when do the pushrods become a limitation, if at all?

I know we're talking apples to oranges when comparing to other engine families, but you mentioned "50's and 60's technology" yet some other engines both small and large had higher peak rpms. Even some American V8's had much higher redlines back then, though not many. Some mid-sixties Corvettes could really rev up with the solid lifter engines.
Not sure which one was the king (L88 maybe?) but I've seen factory 'Vette tachometers with the redline well into the high-6's and low-7's (if I'm remembering correctly).

Just wondering aloud here, other than valvetrain, at what point do other things start to fail to perform, or even fail completely?
A friend of dad's had a heavily modded '63 (completely gutted, washer bottle converted to the fuel tank, etc) and I want to say his rev-limiter was set to 7800 rpm and was reached regularly at autocrosses.
No idea what he'd done internally, but he'd done a lot of work to get it to that point.

Thanks. Just curious what other limitations we deal with.

Paul

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Re: Increase max RPM
Posted by: solo2r ()
Date: May 15, 2019 01:42PM

Do not need discs for autocross! They weigh more than drums. I forgot to mention that I still have drum brakes although I have special shoes ,drums,etc. Have done more than few time trials as well and the drums were adequate even for those.
I have special springs, delrin front bushings, tubular sway bars.

You have a lot of seat time in Your car?

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Re: Increase max RPM
Posted by: LeadFootLogan ()
Date: May 15, 2019 02:05PM

Yeah I say I have about 2 years of seat time. Never went anywhere because it doesn’t run. I am using it for the street as well like cruising around with my friends, and with how people drive today, I need the best brakes I can get.

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