1.7 rr on stock cam?
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SOTP means Seat Of The Pants (a measurement of the feel of power).
I had the Crane/Ford 1.7RR's (still have them on my old heads) with my stock cam and it adds some power. Probably 5-8rwhp I would say.
Be careful with your springs though. If your valvetrain is "old" or has lots of miles on it the springs can experience valve float in the upper rpms. Some upgrade the springs but most of the time in all honesty it isn't needed. But you never can know for sure...
Install help: http://www.cranecams.com/pdf/453e.pdf
I had the Crane/Ford 1.7RR's (still have them on my old heads) with my stock cam and it adds some power. Probably 5-8rwhp I would say.
Be careful with your springs though. If your valvetrain is "old" or has lots of miles on it the springs can experience valve float in the upper rpms. Some upgrade the springs but most of the time in all honesty it isn't needed. But you never can know for sure...
Install help: http://www.cranecams.com/pdf/453e.pdf
rsw007
New Member
MrKwik
Founding Member
Personally I would use that money for a gear. You might see a little gain but it will probably be pretty minimal.
poneypower89
Now everyone in the world will know I wanna bang t
tjm73 said:
You want SOTP feel? Gears will give you that no doubt about it
3:73's on my stang, wouldn't have it any other way.
MrKwik
Founding Member
what they said!
Gears are guaranteed SOTP improvement, rockers could go either way and even if you can feel it...it wont feel like gears.
Gears are guaranteed SOTP improvement, rockers could go either way and even if you can feel it...it wont feel like gears.
crazypete
All my crevices are greased.
I was doing a compression test on a cold engine (yeah yeah, I know) and my hypothesis was that my new crane 1.7 rr's were not sealing right and hence my motor was running like crap. Stamped steel rocker yielded 105 psi of cylinder pressure after 5-6 turnovers. Same cylinder with RR's yielded 115 psi of cylinder pressure after 5-6 turnovers. I know cylinder pressure does not equal power but cylinder pressure is what makes the engine spin and make power. Thats almost 10% increase in pressure. Not bad for $150. You WILL need new rocker covers. No question about it. People say you can grind some baffles or something off....after fouling 3 bits on the aluminum and barely scraping the baffles (and even if they were gone, not even close), just figure a new set of covers into the equation too. You can get some cheapo good looking plain chrome tall ones off ebay for $50.
by the way a bone stock stang with 4.10s will be SO SO SO SO SO much of a difference, you will think you are driving a new car...all without changing idle, emissions, legality or changing anything interesting. You will need an aluminum driveshaft or it will vibrate on the highway. Every once in a while someone gets away with it but eventually the super rotation speed of the shaft will take it's toll. A full gear install with gears is $400-600. Aluminum shafts are like $200 now.
by the way a bone stock stang with 4.10s will be SO SO SO SO SO much of a difference, you will think you are driving a new car...all without changing idle, emissions, legality or changing anything interesting. You will need an aluminum driveshaft or it will vibrate on the highway. Every once in a while someone gets away with it but eventually the super rotation speed of the shaft will take it's toll. A full gear install with gears is $400-600. Aluminum shafts are like $200 now.
Go with 373's...I'll put some info for your gear selection decision. If your worried about "hurting" anything the 373's will technically be better for you over the 410's...even with your AOD...(as referenced by your shift kit).
Go with 373's so it will be more daily driver friendly and if you get boost/nitrous later you won't run out of gear at the track and you will have less traction problems. Some that have actually had both gears were slower at the track with 410's over 373's and some also claimed no seat of the pants difference.
I run 2400 rpm at 70mph (I have 373's) so I don't know how the 410's could run lower
Here is how I look at when picking gears for a daily driver...To me the gearing of 410's or steeper on a daily driver is not worth it to me...you get worse gas mileage/more engine wear/and use your shifting components more (clutch/trans/etc)...around town...and I also look at it like this...when your cruising on the highway at 80mph (interstate) your cruising at roughly 3000rpm with 410's...that is HALF your 302's revving capabilities and that is in the overdrived 5th gear at CRUISE...not at WOT...I personally don't like the idea of having half the engines revving capabilities at just cruise. Also...what if an emergency comes up and you got to "get it"...you have to be there for someone or are running to the hospital...and running higher than 80mph...maybe running 4500rpm steadily (faster than 80mph of course)...during that emergency I don't think that would be a good time for your engine to let go on you...what do you think?
Then you have to factor in 410's or steeper cause my engine braking at higher rpms on the highway...go pull out somewhere and hold your car to 2500rpm or so (worse with gears) and feel the engine try to slow you down when you let off the gas...same similar occurance happens on the highway/interstate plus the wind resistance.
I know when I had the slipping clutch problem I could smell the clutch burn at a higher rpm cruise which in my case was comparing 2000rpm to 2500rpm. At the lower rpm I didn’t smell it but the higher rpm I could smell it. Just some things to think about when you think you want every little tenth out of your car (4:10’s)…I prefer a better overall performance personally…
Go 373's...I would rather want more (373's to 410's) than get to much (410's) and want less (373's)...get what I'm saying?
There will also be less drivetrain shock under traction with 373's over 410's...
The problem with 410's in an AOD is you only have 3 gears to work with at the track (effective gears anyways) and the gears will get you out of those gears quicker and you could lose your gearing powerband at the track.
Also if they were to convert to a t5 (pretty popular actually) then they are "stuck" with the higher revving 410's...I hate the "winding out" sound on the highway with a gear like that...
Exactly on the listing of "pros/cons" of a mod like gears. I have stressed that in a couple choice threads, for example on shorty vs. longtube headers. Longtubes will get a better midranging power over the shortys (so the pro is more power) but some forget to mention the cons of it which are buying a matching mid-pipe (more money and aren't able to use the stock mid-pipe) along with ground clearance issues (especially on a lower car) and also the difficulty of install is "stepped up" quite a bit when trying to get longtubes in. It also can cause heat-soak issues and steering column clearance/rubbing issues. The potential purchaser has to ask themself is the extra midrange worth it? Then you get your answer...
So I ask...are the 410's (a tenth or two quicker at track to a matched combo over 373's) worth it? (more engine/drivetrain wear/worse gas mileage/and a couple other "cons" listed above in my post)...again the potential driver/purchaser has got to ask themselves what they want
willys1 (member on this site) actually was slower at the track in his bolt-on car with 410's than he was with 373's...
To often people go "drive" a friend's car with gears and go have fun in the car and don't drive it normally or thing of longterm effects with normal driving. They often just use their SOTP meter to determine what gear they want but when a final gear ratio effects all different parts of you and your car...I think it is best to not try a gear ratio "drag strip style" but "daily driver style"...
Again good luck with your choice
Go with 373's so it will be more daily driver friendly and if you get boost/nitrous later you won't run out of gear at the track and you will have less traction problems. Some that have actually had both gears were slower at the track with 410's over 373's and some also claimed no seat of the pants difference.
I run 2400 rpm at 70mph (I have 373's) so I don't know how the 410's could run lower
Here is how I look at when picking gears for a daily driver...To me the gearing of 410's or steeper on a daily driver is not worth it to me...you get worse gas mileage/more engine wear/and use your shifting components more (clutch/trans/etc)...around town...and I also look at it like this...when your cruising on the highway at 80mph (interstate) your cruising at roughly 3000rpm with 410's...that is HALF your 302's revving capabilities and that is in the overdrived 5th gear at CRUISE...not at WOT...I personally don't like the idea of having half the engines revving capabilities at just cruise. Also...what if an emergency comes up and you got to "get it"...you have to be there for someone or are running to the hospital...and running higher than 80mph...maybe running 4500rpm steadily (faster than 80mph of course)...during that emergency I don't think that would be a good time for your engine to let go on you...what do you think?
Then you have to factor in 410's or steeper cause my engine braking at higher rpms on the highway...go pull out somewhere and hold your car to 2500rpm or so (worse with gears) and feel the engine try to slow you down when you let off the gas...same similar occurance happens on the highway/interstate plus the wind resistance.
I know when I had the slipping clutch problem I could smell the clutch burn at a higher rpm cruise which in my case was comparing 2000rpm to 2500rpm. At the lower rpm I didn’t smell it but the higher rpm I could smell it. Just some things to think about when you think you want every little tenth out of your car (4:10’s)…I prefer a better overall performance personally…
Go 373's...I would rather want more (373's to 410's) than get to much (410's) and want less (373's)...get what I'm saying?
There will also be less drivetrain shock under traction with 373's over 410's...
The problem with 410's in an AOD is you only have 3 gears to work with at the track (effective gears anyways) and the gears will get you out of those gears quicker and you could lose your gearing powerband at the track.
Also if they were to convert to a t5 (pretty popular actually) then they are "stuck" with the higher revving 410's...I hate the "winding out" sound on the highway with a gear like that...
Exactly on the listing of "pros/cons" of a mod like gears. I have stressed that in a couple choice threads, for example on shorty vs. longtube headers. Longtubes will get a better midranging power over the shortys (so the pro is more power) but some forget to mention the cons of it which are buying a matching mid-pipe (more money and aren't able to use the stock mid-pipe) along with ground clearance issues (especially on a lower car) and also the difficulty of install is "stepped up" quite a bit when trying to get longtubes in. It also can cause heat-soak issues and steering column clearance/rubbing issues. The potential purchaser has to ask themself is the extra midrange worth it? Then you get your answer...
So I ask...are the 410's (a tenth or two quicker at track to a matched combo over 373's) worth it? (more engine/drivetrain wear/worse gas mileage/and a couple other "cons" listed above in my post)...again the potential driver/purchaser has got to ask themselves what they want
willys1 (member on this site) actually was slower at the track in his bolt-on car with 410's than he was with 373's...
To often people go "drive" a friend's car with gears and go have fun in the car and don't drive it normally or thing of longterm effects with normal driving. They often just use their SOTP meter to determine what gear they want but when a final gear ratio effects all different parts of you and your car...I think it is best to not try a gear ratio "drag strip style" but "daily driver style"...
Again good luck with your choice
25thmustang
Mustang Master
crazypete said:
Get the gears hands down, and I do have to say...
I have stock Valve covers with 1.7 rockers, and have even run i with .060 shims and had no rubbing issues at all. I didnt grind anything, and run a cork gasket. I have heard of people needing new ones, but neither me or my dad did with our 1.7 rockers!
crazypete
All my crevices are greased.
Here's how gear selection is done in my opinion:
Select the maximum rpm you would feel comfortable cruising with for extended periods of time. Select your maximum cruising speed you will cruise at for extended periods of time. Not the average but the maximum. Match the two.
I entered that into a calculator:
http://www.4x4cyberstore.com/website/rpmchart.html
and my 16 inch wheels, aod's .67 and 3k rpm at 80 led me to select 4.56's.
_Street_ _domination_. Still get 19-20 mpg highway cruising
3K rpms at LOW LOAD (from the gears inherent torque multiplication) is quite a different 3k rpms from a high load 2.73 or 3.08's 3000 rpms. The engine is spinning fast yes, but not under high load at cruise. You dont really start hurting bearings and such until 3500 or 4000 anyways if your lube and cooling is up to par. You'll wear it out "sooner" but what does that really mean? My engine is already "worn out" on paper. I cant hold synthetic: I'll burn a quart every 150 miles. With regular juice, it burns 1/2 a quart every 1000 miles. Plus as the cylinders wear.....they wear slower since the tolerances increase. You can get away with a lot with a natural aspirated under 5k revver.
Honestly.....I would go 4.30 if I had to do it over again. The 4.56 is just a hair too steep but I dont want to drop the $600 to take such a small step.
Select the maximum rpm you would feel comfortable cruising with for extended periods of time. Select your maximum cruising speed you will cruise at for extended periods of time. Not the average but the maximum. Match the two.
I entered that into a calculator:
http://www.4x4cyberstore.com/website/rpmchart.html
and my 16 inch wheels, aod's .67 and 3k rpm at 80 led me to select 4.56's.
_Street_ _domination_. Still get 19-20 mpg highway cruising
3K rpms at LOW LOAD (from the gears inherent torque multiplication) is quite a different 3k rpms from a high load 2.73 or 3.08's 3000 rpms. The engine is spinning fast yes, but not under high load at cruise. You dont really start hurting bearings and such until 3500 or 4000 anyways if your lube and cooling is up to par. You'll wear it out "sooner" but what does that really mean? My engine is already "worn out" on paper. I cant hold synthetic: I'll burn a quart every 150 miles. With regular juice, it burns 1/2 a quart every 1000 miles. Plus as the cylinders wear.....they wear slower since the tolerances increase. You can get away with a lot with a natural aspirated under 5k revver.
Honestly.....I would go 4.30 if I had to do it over again. The 4.56 is just a hair too steep but I dont want to drop the $600 to take such a small step.
Paul Perreca
New Member
- Mar 30, 2005
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crazypete said:
That is not a very good way to select gears in my opinion. You have to keep in mind this is the poster's daily driver and he has expressed concern (like any daily driver combo should be taken). 4:56's shouldn't even be considered at all into the equation.
crazypete
All my crevices are greased.
My 4.56 equipped, automatic, carbed heavily modded stang is also my daily driver. Nothing like kicking some ass every day during your morning commute. Worth an extra dollar or two in gas.
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