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Hi guys, i have a HT Kingy, TH350 and 2.60 Sal rear end.
Now its gonna be my daily driver on gas and do about 800 kays a week, so economy is necessary.
The 307 has a 1500- 4000 range cam,270 280 advertised, its 40 thou over, 350 heads 1.94 1.50 , 9.1 comp,performer dual plane mani, single 425 impco with spacer, rams horns, free flow exhaust,elec ignition.
I have done some research and see that the 307 makes torque very low( 2200) and max HP ( 4000 ) in standard form,...and i see that my box / diff combo will do say , 104 klm @ 2200 in drive, 65 kays in second @ 2200,and in 1st, its doing about 20 kays @ 1000, 28 @1500, 32 @1700 etc....( well thats without considering stall slippage ) ?
I need to know if i am better of with a standard stall ( 1700 ? ) or should i use a 2200 stall.... i am trying to achieve the best takeoff from the line, and not have it stalling at 100 kays...
Mybee a 2000 would be good ? but how much better than a stock one ?
Thanks for any input :-)
* I know different gears would be good, but i want to run the 2.60.*
I believe its gonna be a slug of the line and would run to 190 kays at 4000 revs in drive....lol...but as i have never owned a 5 litre before and drive a 3 speed manual 186 , i think i will still be impressed :-)
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Not a good combination.
If you want economy, fit a more sensible camshaft. That cam & rear axle ratio will not work together.
The problem will be with a tall 2.60 diff, the RPM around town will be too low for the motor to make any power. With a 270/280 duration cam it won't be happy at all until 2300-2500 RPM, so you will need to drive around town in 1st or 2nd gear.
Either fit a 3.36 diff to get the revs up into the point where the cam works or fit a smaller cam. If you want economy you have no choice, fit the right cam. That cam will only ever be slightly economical at 130 km/h with that rear end.
Dr Terry
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When calculating a car restoration budget, be as accurate as you can & then double the final figure. It will be closer to the truth. |
If at first you don't succeed, just call it Version 1.0 |
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Rank: Member
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Wow, i knew it wasnt the best ratio... but i didnt relaise it was so bad... The cam i have is only a stage 1 , so will i need to fit a dead stock cam ? I do have a Borg warner diff that i could use, its a 3.08 ... i will go and look at the conversion tables again and see if that will get me up to the 2500 revs mark.
Thanks very much for the reply.
Ant
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A 270/280 cam is not a 'stage 1' or mild cam, it will be quite lumpy & a bit short on torque around town.
This stage 1 thing is meaningless drivel, it's the actual duration & lift that matters.
If you want good torque & economy use a cam around 255/260 advertised duration.
Dr Terry
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When calculating a car restoration budget, be as accurate as you can & then double the final figure. It will be closer to the truth. |
If at first you don't succeed, just call it Version 1.0 |
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Rank: Member
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Joined: 23/03/2009(UTC)
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Hi again DR Terry, i originally picked that cam as it was the second one up from the standard replacement cam... its description sounded quite subtle... good idle, good low end torque and throttle response,works well with minimal modifications...( Blue Racer cam cd204-11 )
It has 204/214 duration at 50Thou lift, so i thought this would be a good improvement over standard, considering i need to get lots of LPG in my cylinders to make good power. I was considering advancing this cam 2 degrees to help bring the power curve lower in the rev range, but i ended up installing it straight up.
I know that the stage 1 , stage 2 thing really means nothing :-) and that a cam has duration, lift, and lobe seperation to consider...
And then it has to work with heads, exhaust comp etc...
So... in a nutshell, with this cam and engine specs as previously mentioned, and your recomendation on a 3.36 diff, what stall speed would you recommend for me . Oh, and how many horses would / should my engine make .
Thanks for your good advice, and thanks for helping me learn some more about all this stuff ;-)
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