ring and pinion ratio suggestion

[MOPAla]

Hello,

as the title says I would appreciate some advice on rear ratio for my setup.
Have not scaled but I'd bet the car weights less than 3000 lbs. Believe something between 2900 and 2950 pounds.
The 4 speed manual gearbox ratios:
2.92:1 -> 2.03:1 -> 1.42:1 -> 1.00:1
The tire:
245/60 R14 regular street tires (about 25,57 inches of diameter)
The rear axle:
Dana 44 with the option of ring sets from 2,xx up to 3,73:1.
The engine:
318 LA block, ported iron heads with bigger 2.02" and 1.60" valves. The compression is about 9.4:1 with a regular gasket.
Important notes about the head:
-Don’t know if the head casting is the same of yours from the 60’s and early 70’s, but I think they are.
-Also don’t know if the porting job is good or bad, can’t flow heads here. I do believe they’re at least a little better than stock, by looks.

I have a programmable Electronic Fuel Injection (EFI) thing that also controls spark timing without a distributor, so I believe the engine will be more docile and better to drive than what it would have been with a carb. It has an Air-Gap intake modified to fit the throttle body and 8 fuel injectors for the EFI, has Summit ‘Block Huggers’ short tubes 1-5/8” diameter exhaust manifolds, 2.5” dual exhaust with H-pipe and mufflers.

The camshaft is a Howards hydraulic (int/exh) 265/273 adv, 218/226 @0,050” with 0.502”/0.525” lift, LSA is 110º. RPM range says 1800-5600 but I don’t know for which engine (318, 340 or 360). Lifters are Comp Cams ‘ Pro Magnum’ P/N 867-16 (a higher RPM, higher abuse type of hyd lifters. No relation with the Mopar Magnum name) and I have some old adjustable rocker arms with ball/cup pushrods (think they came from those 273’s).

The point of the car:

Although it’s a light car it has everything inside: bench seats, power steering, power brakes, will buy an air conditioning system, will have some radio. It is smaller than a Chevy Nova. As you might have figured I’m not in USA. I’ll not drag race it, but I do want some of the punch, some of the ‘muscle car’ thing in it. That’s why I chose that gearbox ratio (the other option was a close-ratio). My goal is to have it going strong/fast from first through third gear and have the fourth to drive at 65 mph without having the engine screaming at trips. But I have no other car to compare with it, so I wanted to ask you who have had experiences with different rear end ratios, vehicle weights, close and wide ratio gearboxes…

Initially I thought about 3.07:1. Then thought it might be too long and thought about 3.31:1… maybe 3.54:1. I’ve read a lot of threads on this and other forums, but you guys usually have way heavier cars with close-ratio gearboxes and who-knows-what tires, so I can’t compare.

I’ll stop, sorry it’s too long. Thanks

 

[Coffee&Cars]

Hello,

as the title says I would appreciate some advice on rear ratio for my setup.
Have not scaled but I'd bet the car weights less than 3000 lbs. Believe something between 2900 and 2950 pounds.
The 4 speed manual gearbox ratios:
2.92:1 -> 2.03:1 -> 1.42:1 -> 1.00:1
The tire:
245/60 R14 regular street tires (about 25,57 inches of diameter)
The rear axle:
Dana 44 with the option of ring sets from 2,xx up to 3,73:1.
The engine:
318 LA block, ported iron heads with bigger 2.02" and 1.60" valves. The compression is about 9.4:1 with a regular gasket.
Important notes about the head:
-Don’t know if the head casting is the same of yours from the 60’s and early 70’s, but I think they are.
-Also don’t know if the porting job is good or bad, can’t flow heads here. I do believe they’re at least a little better than stock, by looks.

I have a programmable Electronic Fuel Injection (EFI) thing that also controls spark timing without a distributor, so I believe the engine will be more docile and better to drive than what it would have been with a carb. It has an Air-Gap intake modified to fit the throttle body and 8 fuel injectors for the EFI, has Summit ‘Block Huggers’ short tubes 1-5/8” diameter exhaust manifolds, 2.5” dual exhaust with H-pipe and mufflers.

The camshaft is a Howards hydraulic (int/exh) 265/273 adv, 218/226 @0,050” with 0.502”/0.525” lift, LSA is 110º. RPM range says 1800-5600 but I don’t know for which engine (318, 340 or 360). Lifters are Comp Cams ‘ Pro Magnum’ P/N 867-16 (a higher RPM, higher abuse type of hyd lifters. No relation with the Mopar Magnum name) and I have some old adjustable rocker arms with ball/cup pushrods (think they came from those 273’s).

The point of the car:

Although it’s a light car it has everything inside: bench seats, power steering, power brakes, will buy an air conditioning system, will have some radio. It is smaller than a Chevy Nova. As you might have figured I’m not in USA. I’ll not drag race it, but I do want some of the punch, some of the ‘muscle car’ thing in it. That’s why I chose that gearbox ratio (the other option was a close-ratio). My goal is to have it going strong/fast from first through third gear and have the fourth to drive at 65 mph without having the engine screaming at trips. But I have no other car to compare with it, so I wanted to ask you who have had experiences with different rear end ratios, vehicle weights, close and wide ratio gearboxes…

Initially I thought about 3.07:1. Then thought it might be too long and thought about 3.31:1… maybe 3.54:1. I’ve read a lot of threads on this and other forums, but you guys usually have way heavier cars with close-ratio gearboxes and who-knows-what tires, so I can’t compare.

I’ll stop, sorry it’s too long. Thanks

Hello,

as the title says I would appreciate some advice on rear ratio for my setup.
Have not scaled but I'd bet the car weights less than 3000 lbs. Believe something between 2900 and 2950 pounds.
The 4 speed manual gearbox ratios:
2.92:1 -> 2.03:1 -> 1.42:1 -> 1.00:1
The tire:
245/60 R14 regular street tires (about 25,57 inches of diameter)
The rear axle:
Dana 44 with the option of ring sets from 2,xx up to 3,73:1.
The engine:
318 LA block, ported iron heads with bigger 2.02" and 1.60" valves. The compression is about 9.4:1 with a regular gasket.
Important notes about the head:
-Don’t know if the head casting is the same of yours from the 60’s and early 70’s, but I think they are.
-Also don’t know if the porting job is good or bad, can’t flow heads here. I do believe they’re at least a little better than stock, by looks.

I have a programmable Electronic Fuel Injection (EFI) thing that also controls spark timing without a distributor, so I believe the engine will be more docile and better to drive than what it would have been with a carb. It has an Air-Gap intake modified to fit the throttle body and 8 fuel injectors for the EFI, has Summit ‘Block Huggers’ short tubes 1-5/8” diameter exhaust manifolds, 2.5” dual exhaust with H-pipe and mufflers.

The camshaft is a Howards hydraulic (int/exh) 265/273 adv, 218/226 @0,050” with 0.502”/0.525” lift, LSA is 110º. RPM range says 1800-5600 but I don’t know for which engine (318, 340 or 360). Lifters are Comp Cams ‘ Pro Magnum’ P/N 867-16 (a higher RPM, higher abuse type of hyd lifters. No relation with the Mopar Magnum name) and I have some old adjustable rocker arms with ball/cup pushrods (think they came from those 273’s).

The point of the car:

Although it’s a light car it has everything inside: bench seats, power steering, power brakes, will buy an air conditioning system, will have some radio. It is smaller than a Chevy Nova. As you might have figured I’m not in USA. I’ll not drag race it, but I do want some of the punch, some of the ‘muscle car’ thing in it. That’s why I chose that gearbox ratio (the other option was a close-ratio). My goal is to have it going strong/fast from first through third gear and have the fourth to drive at 65 mph without having the engine screaming at trips. But I have no other car to compare with it, so I wanted to ask you who have had experiences with different rear end ratios, vehicle weights, close and wide ratio gearboxes…

Initially I thought about 3.07:1. Then thought it might be too long and thought about 3.31:1… maybe 3.54:1. I’ve read a lot of threads on this and other forums, but you guys usually have way heavier cars with close-ratio gearboxes and who-knows-what tires, so I can’t compare.

I’ll stop, sorry it’s too long. Thanks

 

[Coffee&Cars]

Considering the gear ratios in your tranny I would go with the 3.07. That is if you really want to get out and drive this car and put some miles on her at highway speed. If you want a little more bottom end a 3.23 would be better. Anything more than this will really kill your fuel mileage.

 

[stroked340]

3:73's..that baby will rock..if your worried about gas mileage buy a volkswagon..

 

[Killer6]

If You really want compromise, I would say the 3.31's, that's about 2825 RPM@65 MPH. Not "screaming", but it's up there a bit, w/it You'll get an 8% improvement over 3.07's
in Your takeoff gear. Your 'teener will appreciate that!

 

[RPMagoo]

-- If You really want compromise, I would say the 3.31's, that's about 2825 RPM@65 MPH. Not "screaming", but it's up there a bit, w/it You'll get an 8% improvement over 3.07's
in Your takeoff gear. Your 'teener will appreciate that! --

-- I agree -- 3.73s would be close to 3,200 RPMs at 65 MPH, due to rather small tires. -

 

[MOPAla]

I was waiting for more inputs from other members, that's why I didn't reply any of you before.
-Coffee&Cars, thank you for your reply;
-Stroked340, I really think it would 'wake up' the car and make it very cool, but for long trips that 3,73:1 would keep reminding me of that decision. Although you had me itching for that, haha. Think it would be an awsome weekend car (maybe 4,10...)
-Killer6, I really was inclined to the 3,31 for the exactly reason you pointed. 8% more 'grunt' to the rear wheels without that much more rpm on 4th. I think this would be the best, but I don't know yet in which rpm the camshaft will start making good power.

So, before opening the thread I did the calculations, and it ends up been small steps of a little less than 200 rpm for each rear ratio 'step'. The thing was that I don't know if a V8 driving at 2900 rpm is just a little or a lot louder than the same engine at 2700 rpm. Than I've found some youtube videos of people driving around showing the tachometer, but I don't know if their car had full exhaust, what kind of engine...
So I think I'll go with 3.55:1 because I'll change the wheels and tires when I have more money.
If after putting the 3.55 I feel the gears are too short with the current tires, than I'll buy bigger 27" tires to even out and make it as if I had the 3.31:1 in the first place.

Thanks for the replys

 

[QuickDart360]

Have 3.55 here. They are ok I will go with 3.91 for the fun factor. Rpms are only 500 to 600 more so I can live with that.

 

[Swifster]

MOST Chryslers used 3.23's in the axle. It's a decent compromise between driving it around town and having a bit of grunt taking off. I have two Studebakers with Dana 44's. One is a factory 4-Speed and that has a 3.31. The other has a GM 4L60E trans and a 3.54. That trans came out of late '90's Camaro and that car had 3.42's

My suggestion if you have a Dana 44 is to go with the 3.31's. Unless you are going to be getting on it on a regular basis, this is a good compromise. It you're going to get on it, use the 3.54's.

 

[RustyRatRod]

Would you mind telling us what "car" this is?

 

[AJ/FormS]

That cam is about the same as a factory 340 cam, with some extra lift. So what you seem to be ending up with is a warmed up teener with a possibly ever so slightly, soggy bottom end with just a 9.4 compression ratio.(EDIT; Naw, I changed my mind, the Dcr comes in at about 7.8@155 psi. I don't see that as soggy at your weight and with a reasonable rear-gear.)The 2.92 low gear will help,as will the light chassis, and the H-pipe. IMO this cam will want a starter gear of around 10. I'm guessing 10/1 will be sufficient. That means a rear gear of about 3.42.
Since you offered options of 3.31 and 3.54, the final decision may have to be the hiway revs..
3.31s will cruise at 65=2670, 3.54s at 2860. Both with 27s. That is to say about 190rpm difference. I have cruised at both rpms and many others. With a good 3-pass muffler and full exhaust, this is no problem as to noise, just make sure the exhaust does not exit under the car.
This engine will be capable of great fuel mileage, and with the 9.4Scr, and about 7.8 Dcr, you should be able to run some pretty low-octane gas in it, at least on the hiway. To that end,when in doubt, err on the conservative side,3.31s in this case. With such a light chassis, you will want some bigger tires under there, to try and grab traction. If you can fit 28s in there, then you can run the 3.54s, for 65=2760rpm, right up the middle!
BTW
That's a real nice tranny; the splits are pretty even at right around 70%. What's that come from, and is there a bellhouse to bolt it right up to the engine?

 

[MOPAla]

Would you mind telling us what "car" this is?

It's a Chevrolet Opala, first gen. I didn't say it because the first reply I get is 'did you mean Impala?' and it was made looking like this only here in Brasil. The info on wikipedia is not 100% accurate, but it's basically there if you wanna take a look. Mine looks like this, minus the square lights in the front, the mirrors are round chromed, and my color is a way darker metallic brown:

That cam is about the same as a factory 340 cam, with some extra lift. So what you seem to be ending up with is a warmed up teener with a possibly ever so slightly, soggy bottom end with just a 9.4 compression ratio.(EDIT; Naw, I changed my mind, the Dcr comes in at about 7.8@155 psi. I don't see that as soggy at your weight and with a reasonable rear-gear.)The 2.92 low gear will help,as will the light chassis, and the H-pipe. IMO this cam will want a starter gear of around 10. I'm guessing 10/1 will be sufficient. That means a rear gear of about 3.42.
Since you offered options of 3.31 and 3.54, the final decision may have to be the hiway revs..
3.31s will cruise at 65=2670, 3.54s at 2860. Both with 27s. That is to say about 190rpm difference. I have cruised at both rpms and many others. With a good 3-pass muffler and full exhaust, this is no problem as to noise, just make sure the exhaust does not exit under the car.
This engine will be capable of great fuel mileage, and with the 9.4Scr, and about 7.8 Dcr, you should be able to run some pretty low-octane gas in it, at least on the hiway. To that end,when in doubt, err on the conservative side,3.31s in this case. With such a light chassis, you will want some bigger tires under there, to try and grab traction. If you can fit 28s in there, then you can run the 3.54s, for 65=2760rpm, right up the middle!
BTW
That's a real nice tranny; the splits are pretty even at right around 70%. What's that come from, and is there a bellhouse to bolt it right up to the engine?

First, thank you for the well writen, well explained and complete answer. I wanted that info about exhauts, noise at rpm and what you said clarified.
-About 28" tires: here it's hard to find tires for these cars. I have 245/60 R14 (25.6" diameter) I mentioned and thought a good alternative was to buy 235/60 r16 (these are not that expensive, both wheels and tires). These measure about 27.1" diameter.
-Fuel: 'pump gas' here are E27 (27% ethanol, 73% regular octane gasoline). I don't think CR will be a problem at all. Thought about raising it up to 10, but I don't want to mill the heads and everything else.
-Transmission: Isn't it a nice ratio? Here we've had 1 good, strong transmission project/design called Clark 260F with many ratios.
Clark is the brand, the number is the torque rating 260 lb-ft and F if 'Four speed' (there is also a 'T', 3 speed). Although the rating looks low, it actually withstands a lot more. People usually drag race it with turbo cars.
So this 4 speed had:
-my ratio on Ford Maverick GT (302 V8);
-a close-ratio on all 4 speed V8 Dodges, and all V8 Dodges were 318s.
-and pick-up wide-ratios for both Ford and GM, inline 6, diesel, no V8 though (I believe more than 1 ratio).
The differences were the bellhousing, the input shaft is different for each ratio and the input shafts lenght. So I'll have to make the input shaft about 1" longer to fit the 318 using the Ford ratio.

Sorry I went too long again.

 

[Killer6]

Lol, guess that explains the user name! No Apologies needed, most of us like details, it's all good! I guess You have to decide if You want to go 3.54 & live with the car
sitting 3/4" higher if You feel it's too much & do the 16" rim switch. Plus, not certain of the options in each size to You, also a consideration. 27" looks like a tight fit on
that car, how much room will that leave you? Neat ride BTW!

 

[MOPAla]

For what I've been reading the bigger the tire's diameter, the better off-the-line traction, because of it's "footprint". Is it right?
My idea was to have 5 equal tires and wheels. The 245/60 R14 are already a tight fit all around. I was ok with opening the wheels arches (flares?) to fit larger tires, but I already have a pair of brand new 245/60 R14 and today I've found a guy willing to trade his wheels for mine (mine's?), so I think I'll trade it, fit my tires for now and just buy a second pair of 245s later. Planning to paint the new wheels and make then look like this: