Swap 3.27 for current 3.55 in 65 monza 110 4 speed.

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Mcwho
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Swap 3.27 for current 3.55 in 65 monza 110 4 speed.

Post by Mcwho »

My mechanic is diagnosibg the car now. Looks like i may new trans and possably trans also. Currintly with a code AB diff it seems to run at 4000 rpm or so. Would swappinng for a 3.27 ratio make it feel less like a jet engine ? Thoughts on drivability or 3.27 over the current 3.55. Im in florida where its flat.

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1965 Corvair Monza Coupe 110, 4 speed, Liberty Blue

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Mcwho
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Re: Swap 3.27 for current 3.55 in 65 monza 110 4 speed.

Post by Mcwho »

Meant to say may need trans and differential.

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1965 Corvair Monza Coupe 110, 4 speed, Liberty Blue

66vairguy
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Re: Swap 3.27 for current 3.55 in 65 monza 110 4 speed.

Post by 66vairguy »

The first thing to check is tire size. A fellow in our club had small low profile tires. The speedometer read 12 MPH too fast and at a real 70MPH the engine was screaming! The ideal tire is 825 revolutions per mile. Easy to check. Chalk tire a couple revolutions to get a good "rolling" average. Divide that into the inches per mile and you've got your revolutions per mile. The old 6.50X13 tires were about 865 revolutions per mile and the 66 and on 7.00X13 tires were about 835 revolutions per mile (yes it makes an ideal speedometer read a little fast, but that was done to allow for speedometer and tire variations).

If the tires size if fine you can still go with a 3.27 to 1 axle if you feel the need to. I have two cars, one a 3.55 and one a 3.27. I run bigger tires that are 828 revolutions per mile. There isn't a huge difference between the gear ratios. The 3.55 car is an in-town cruiser and I like the easy start off in 1st. The 3.27 car is more of a road car and at 70MPH runs the engine turns about 250RPM slower which isn't much, but makes a difference on the road. Starting off in 1st. isn't as quick.

As far as the transaxle repair goes. Find a good Corvair specific rebuilder, not some generic transmission shop. The Corvair transaxle has some rebuild idiosyncrasies. Very hard to find a good used ones now. Most fail because few ever changed the lubrication. Our local transaxle expert rebuilds them for a vendor and he says most now need a lot of parts. The vendor was using a basic transmission shop and HALF the units were coming back with problems so the vendor went with the our local expert for rebuilds.

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bbodie52
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Re: Swap 3.27 for current 3.55 in 65 monza 110 4 speed.

Post by bbodie52 »

66vairguy wrote:...The ideal tire is 825 revolutions per mile...
Below are some 14" tire options that can do well on the Corvair. These provide some options for those who want more performance choices than those available in the narrow options found in the obsolete 13" wheel size. More choices can be researched in 15" and larger for mostly late model Corvairs, but to maintain a proper overall tire diameter, the tire profile must become increasingly low profile with a somewhat narrow, stiff sidewall.

Sizing Corvair Wheels and Tires
http://autoxer.skiblack.com/tires.html

Warning: many currently available 13" tires are not designed for passenger cars, and are specified for use on trailers only.

The MAXXIS 185/80R13 is currently a commonly recommend choice for the Corvair, as there are few other brands offered in this size. The even smaller 175/70R13 passenger car tire begins to present an overall diameter that is significantly too small for the Corvair, which will take engine RPM speed much higher at conventional highway speed limits. The tread contact patch is also smaller, which can have a negative impact on handling and braking.

185/80R13
OVERALL DIAMETER: 24.7" REVS PER MILE: 842 TREAD WIDTH: 4.7" SECTION WIDTH: 7.2" SIZE: 185/80R13
MAXXIS 185/80R13: RIM WIDTH RANGE: 5.0"-6.5" SECT. WIDTH: 7.4" TREAD WIDTH: 5.4" OVERALL DIAM: 24.7" REVS. PER MILE: N/A
175/70R13
OVERALL DIAMETER: 22.7" REVS PER MILE: 881 TREAD WIDTH: 5.1" SECTION WIDTH: 7" KUMHO SOLUS TA11 - SIZE: 175/70R13
OVERALL DIAMETER: 22.6" REVS PER MILE: 919 TREAD WIDTH: 5.1" SECTION WIDTH: 7" GENERAL ALTIMAX RT43 (T-SPEED RATED) - SIZE: 175/70R13


14" WHEELS

Image
DEFENDER T+H - SIZE: 195/70R14
OVERALL DIAM: 24.8" REVS. PER MILE: 839
https://www.tirerack.com/tires/tires.js ... mpare1=yes
The Defender T+H tire is Michelin's Standard Touring All-Season tire developed for the drivers of coupes, family sedans, minivans and small crossover vehicles looking for a long-lasting, comfortable tire that delivers all-season traction in the dry, wet and light snow...

Image
TIGER PAW AWP 3 - SIZE: 195/70R14
OVERALL DIAM: UNSPECIFIED REVS. PER MILE: UNSPECIFIED
https://www.tirerack.com/tires/tires.js ... mpare1=yes
Standard Touring All-Season tires are for drivers who want a combination of sporty appearance, long wear, predictable handling and S- or T-speed rated durability, along with all-season traction including in light snow. Standard Touring All-Season tires branded with the M+S symbol are often used as Original Equipment (O.E.) on sporty coupes and sedans...

Image
ALL SEASON - SIZE: 195/70R14
OVERALL DIAM: 24.8" REVS. PER MILE: 840
https://www.tirerack.com/tires/tires.js ... mpare1=yes
The All Season is Firestone's Passenger All-Season tire developed for the drivers of coupes, sedans, family minivans and crossover vehicles looking for a tire that combines year-round capability and ride comfort with long tread life...

Image
ASSURANCE ALL-SEASON - SIZE: 195/70R14
OVERALL DIAM: 24.8" REVS. PER MILE: 843
https://www.tirerack.com/tires/tires.js ... mpare1=yes
The Assurance All-Season is Goodyear's entry-level Passenger All-Season member of their Assurance family of tires. Developed for drivers of family sedans and minivans looking for practical tires that provide confident all-season traction, the Assurance All-Season delivers Goodyear value by combining attractive pricing, long wear and year-round traction in dry, wet and wintry conditions, even in light snow.

Image
SPRINT CLASSIC - SIZE: 195/70VR14
OVERALL DIAM: 24.8" REVS. PER MILE: 841
https://www.tirerack.com/tires/tires.js ... mpare1=yes
The Sprint Classic is Vredestein's Grand Touring Summer tire developed for drivers of classic automobiles who want a tire with vintage style combined with modern technology. Like all summer tires, the Sprint Classic is not intended to be serviced, stored nor driven in near- and below-freezing temperatures, through snow or on ice.

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

Image
RADIAL T/A - SIZE: P205/70R14
OVERALL DIAM: 25.4" REVS. PER MILE: 821
https://www.tirerack.com/tires/tires.js ... mpare1=yes
The Radial T/A is BFGoodrich's Performance All-Season tire developed for the drivers of muscle cars, kit cars, street rods and light trucks looking for wide, low profile, white-lettered performance tires. Today's Radial T/A tires are designed to combine classic looks and size range with modern manufacturing methods and year-round traction, even in light snow...

Image
KINERGY ST - SIZE: 205/70R14
OVERALL DIAM: 26" REVS. PER MILE: 824
https://www.tirerack.com/tires/tires.js ... mpare1=yes
The Kinergy ST is Hankook's Standard Touring All-Season tire developed for the drivers of family sedans, crossovers, coupes and minivans who want a balanced blend of performance combined with long tread life. The Kinergy ST was designed to deliver a smooth and quiet ride along with confident traction in dry, wet and wintry conditions, even light snow...
Image
ALTIMAX RT43 (T-SPEED RATED) - SIZE: 205/70R14
OVERALL DIAM: 25.3" REVS. PER MILE: 821
https://www.tirerack.com/tires/tires.js ... mpare1=yes
AltiMAX RT43 (Road Touring) tires featuring T-speed ratings are General's Standard Touring All-Season tire members of their AltiMAX family of flagship tires. Designed to deliver impressive consumer value through even treadwear and extended treadlife, the AltiMAX RT43 combines a quiet, comfortable ride with year-round, all-season traction, even in light snow...
Image
CINTURATO CN36 - SIZE: 205/70R14
OVERALL DIAM: UNSPECIFIED REVS. PER MILE: UNSPECIFIED
https://www.tirerack.com/tires/tires.js ... mpare1=yes
The Cinturato CN36 is Pirelli's High Performance Summer tire developed for drivers of classic automobiles who want modern tire technology combined with vintage good looks and driving feel. Like all summer tires, the Cinturato CN36 is not intended to be serviced, stored nor driven in near- and below-freezing temperatures, through snow or on ice...
NOTE: THE TIRES LISTED ABOVE ARE ONLY A SAMPLE OF THOSE OFFERED ON THE TIRE RACK WEBSITE. PLEASE CHECK THEIR WEBSITE FOR ADDITIONAL TIRES AND BRANDS OFFERED IN THESE SIZES
Brad Bodie
Lake Chatuge, North Carolina
Image 1966 Corvair Corsa Convertible

joelsplace
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Re: Swap 3.27 for current 3.55 in 65 monza 110 4 speed.

Post by joelsplace »

3.55 should go 60mph at 3000rpm
114 Corvairs, 5 Ultravans and counting
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Mcwho
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Re: Swap 3.27 for current 3.55 in 65 monza 110 4 speed.

Post by Mcwho »

My tires are bgs radial ta 205/60 15.

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1965 Corvair Monza Coupe 110, 4 speed, Liberty Blue

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Mcwho
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Re: Swap 3.27 for current 3.55 in 65 monza 110 4 speed.

Post by Mcwho »

Diameter of tire is 24.6"

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1965 Corvair Monza Coupe 110, 4 speed, Liberty Blue

66vairguy
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Re: Swap 3.27 for current 3.55 in 65 monza 110 4 speed.

Post by 66vairguy »

Mcwho wrote:
Tue Jul 21, 2020 9:52 am
Diameter of tire is 24.6"

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Diameter isn't that accurate. The online sites for revolutions per mile indicate the 205/60X15 is about 818 revolutions per mile. Close to the factory speedometer 825 revolutions per mile. HOWEVER some tire sites use the manufacturers dimensions and as we all know a tire squishes a little under the weight of a car. The best way is to chalk the tire and roll the the car at least two tire rotations and measure. That gives you "rolling" circumference. In your case at 60 the speedometer will be right on or maybe indicate one mile slow.

BTW -- Compared to modern cars with overdrive the Corvair engine does sound busy on the highway, but it's normal. Running these older engines too slow under load is not advised since the piston wrist pins need the oil sling off the crank at higher RPM. A 3.08 axle ratio is considered the lowest numerical number to use and not advised if you live in an area with hills.

erco
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Re: Swap 3.27 for current 3.55 in 65 monza 110 4 speed.

Post by erco »

Pretty big "DIFF" -erence in driving torque between 3.27 and 3.55. You gotta pick either 3.55 for more torque (fun driving) or 3.27 for quieter highway cruise (possibly better mileage). You can't have it all with a stock 4-speed transmission.

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Mcwho
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Re: Swap 3.27 for current 3.55 in 65 monza 110 4 speed.

Post by Mcwho »

Yeay maybe a 3.55 e a 5 speed.
Anywsy we put shiftrr linkGe kit in it hss decreased shifter rravel by at least 25%. Still have rear end noise issues.

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1965 Corvair Monza Coupe 110, 4 speed, Liberty Blue

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Mcwho
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Re: Swap 3.27 for current 3.55 in 65 monza 110 4 speed.

Post by Mcwho »

I mean to say shift travel is 1/4 of what it was, very tight.

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1965 Corvair Monza Coupe 110, 4 speed, Liberty Blue

erco
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Re: Swap 3.27 for current 3.55 in 65 monza 110 4 speed.

Post by erco »

Only forward and reverse shifter travel get reduced by a quick shift kit, right? Left/right travel remains the same since it's angular displacement?

joelsplace
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Re: Swap 3.27 for current 3.55 in 65 monza 110 4 speed.

Post by joelsplace »

No, it tightens it all up since it is changing the lever ratio. The lever also rotates the shaft quicker.
114 Corvairs, 5 Ultravans and counting
Northlake, TX

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Mcwho
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Re: Swap 3.27 for current 3.55 in 65 monza 110 4 speed.

Post by Mcwho »

I purchased a used trans and diff. Gonna use the trans after we get it cheked out. So i have 2 diffs now that are ok. A 3.27 and a 3.55 (was installed). Decided to go with the 3.55 that was in it when purchased as most driving is local, to shows etc.

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1965 Corvair Monza Coupe 110, 4 speed, Liberty Blue

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