power through timing
luxeryvic
07-19-2008, 11:34 AM
what is the best position for valve and ignition timing( advanced or delayed) for a 305 to get the most power out of it, ive heard that advancing it is the best but by how much?
i have a summit cam in it
the specs are
duration- 204/214
lift- .420/.442
i have a summit cam in it
the specs are
duration- 204/214
lift- .420/.442
Blue Bowtie
07-20-2008, 06:20 AM
What kind of power? Typically, advancing the valve timing will move maximum torque to a lower RPM range (more torque), and retarding valve timing will move maximum torque to a higher RPM range (more HP). Depending upon the induction system, static compression, port runner volumes, valve sizes, final gear ratio, weight of the vehicle, intended use of the vehicle, and numerous other variables and goals, you can determine what is best for your application.
luxeryvic
07-20-2008, 08:07 AM
its in a 77 monte carlo, a big heavy car so i want low end torque, how much do i advance the valve timing then?
i just want to be able to squeal the tires a bit and have some fun, its a 2.73 rear end and the 305 is mostly stock except for the q-jet, cam and headers
what do i do with the ignition timing then if i advance the valve timing?
thanks
i just want to be able to squeal the tires a bit and have some fun, its a 2.73 rear end and the 305 is mostly stock except for the q-jet, cam and headers
what do i do with the ignition timing then if i advance the valve timing?
thanks
silicon212
07-20-2008, 02:06 PM
Don't advance it more than 4 degrees. Use a timing sprocket set for the occasion - most have 3 notches on the crank sprocket: 1, normal, 2, 4 degrees advanced, 3, 4 degrees retarded. Some better kits have removable sleeves on the cam sprocket for this purpose, and are more adjustable in this regard.
Ignition timing remains the same.
You're not likely to squeal the tires on that boat with a 305, unless it's hot outside and you're on slick concrete. The car is 4200 lbs and a 305 is not the 'ideal engine' for it. It will work, just not tire-squealingly (NEW WORD!) with a 2.73 ratio.
Ignition timing remains the same.
You're not likely to squeal the tires on that boat with a 305, unless it's hot outside and you're on slick concrete. The car is 4200 lbs and a 305 is not the 'ideal engine' for it. It will work, just not tire-squealingly (NEW WORD!) with a 2.73 ratio.
Blue Bowtie
07-20-2008, 03:54 PM
With an open differential, some old-school F78-14 bias ply tires, and judicious application of launch power, you should be able to get one tire to smoke.
If it's going to be primarily a street vehicle, you'll want to maintain as much low-end torque as possible. If it's an original TH350 trans, there is little chance it has a lockup torque converter, so minimizing stall RPM is going to provide the best fuel mileage. Ideally, a conversion to a TH200-4R or 700-R4 with OD and lockup would give you really improved fuel mileage, at least in highway driving. The 700-R4 also has a fairly deep first gear ratio, which would help launches.
If it's going to be primarily a street vehicle, you'll want to maintain as much low-end torque as possible. If it's an original TH350 trans, there is little chance it has a lockup torque converter, so minimizing stall RPM is going to provide the best fuel mileage. Ideally, a conversion to a TH200-4R or 700-R4 with OD and lockup would give you really improved fuel mileage, at least in highway driving. The 700-R4 also has a fairly deep first gear ratio, which would help launches.
luxeryvic
07-21-2008, 08:36 AM
ive never heard of those tires, what are they like and where could i get some?
my friend has a 68 firebird with a strait 6, and he can barely squeal the one tire ( open diff ) it would be pretty funny if i cound really burn some rubber in my boat lmao
also, i dont want to change the tranny, first car, trying to get it on the road the way it is first
my friend has a 68 firebird with a strait 6, and he can barely squeal the one tire ( open diff ) it would be pretty funny if i cound really burn some rubber in my boat lmao
also, i dont want to change the tranny, first car, trying to get it on the road the way it is first
MagicRat
07-21-2008, 08:48 AM
If you want to smoke one tire, soak it in WD-40 before spinning. However, one-wheel-wonders tend to be hard on the differential, so I do not recommend it.
Good advice as posted above about valve timing. Note in the 70's, valve timing was often retarded about 4 degrees from optimal as a form of primitive emissions control, so your engine should respond (slightly) to the change.
Good advice as posted above about valve timing. Note in the 70's, valve timing was often retarded about 4 degrees from optimal as a form of primitive emissions control, so your engine should respond (slightly) to the change.
silicon212
07-21-2008, 01:05 PM
ive never heard of those tires, what are they like and where could i get some?
I am not sure who makes them these days. They're old and were replaced with radial tires. The reason is that radial tires have a great deal more traction (which is why BB said to get these). They went 'out of style' in the mid 70s.
On a radial, the strength is in the tread, where on a bias ply, the strength is in the sidewall.
I am not sure who makes them these days. They're old and were replaced with radial tires. The reason is that radial tires have a great deal more traction (which is why BB said to get these). They went 'out of style' in the mid 70s.
On a radial, the strength is in the tread, where on a bias ply, the strength is in the sidewall.
luxeryvic
07-22-2008, 09:00 PM
ok about the crank gear? mine doesnt have the other slots, can i do it by just moving around the timing dots on the gears? or do i have to buy one?
also, how do you get the gear off? do i use a puller?
and how do i put it back on ? isnt it pressed on?
also, how do you get the gear off? do i use a puller?
and how do i put it back on ? isnt it pressed on?
luxeryvic
07-24-2008, 09:15 PM
so, do they still make these tires, or will i have to find old used ones?
silicon212
07-24-2008, 09:29 PM
You can still get them, but don't EVER use old tires. Not if you value your ability to breathe on your own.
silicon212
07-25-2008, 03:18 AM
ok about the crank gear? mine doesnt have the other slots, can i do it by just moving around the timing dots on the gears? or do i have to buy one?
also, how do you get the gear off? do i use a puller?
and how do i put it back on ? isnt it pressed on?
If you don't have the ability to change the timing on your current set, get one that you can. Most aftermarket sets (not the el-cheapo replacement ones) have the +4, 0 and -4 settings. Don't move the chain a notch over.
You can remove the crank gear with a puller, you can install the new one by sitting it on the crank nose and then slipping a piece of pipe over the crank nose, and then carefully driving it on with a hammer. You only need to drive it on that last 3/4" or so, most of the area of the crank nose is slightly smaller in diameter and the gear will slip right over it.
By "notches in the crank gear", I mean notches for the Woodruff key in the crank nose. Each 'notch' has a corresponding timing mark. The 0 degree mark is the standard dot, while the other two are usually a triangle and square or other shapes like that. The instructions that come with the timing set will explain. My engine has an Edelbrock true roller set on it (which has lasted, thus far, ~300k miles) and has the dot, triangle and square. FWIW, it's on zero time (pretty accurate on a degree wheel).
also, how do you get the gear off? do i use a puller?
and how do i put it back on ? isnt it pressed on?
If you don't have the ability to change the timing on your current set, get one that you can. Most aftermarket sets (not the el-cheapo replacement ones) have the +4, 0 and -4 settings. Don't move the chain a notch over.
You can remove the crank gear with a puller, you can install the new one by sitting it on the crank nose and then slipping a piece of pipe over the crank nose, and then carefully driving it on with a hammer. You only need to drive it on that last 3/4" or so, most of the area of the crank nose is slightly smaller in diameter and the gear will slip right over it.
By "notches in the crank gear", I mean notches for the Woodruff key in the crank nose. Each 'notch' has a corresponding timing mark. The 0 degree mark is the standard dot, while the other two are usually a triangle and square or other shapes like that. The instructions that come with the timing set will explain. My engine has an Edelbrock true roller set on it (which has lasted, thus far, ~300k miles) and has the dot, triangle and square. FWIW, it's on zero time (pretty accurate on a degree wheel).
luxeryvic
07-25-2008, 08:32 AM
ok then, thanks for the advice lol anyway , where can i get these tires ,ill have to do a google search
MagicRat
07-25-2008, 01:09 PM
, where can i get these tires
These people are the biggest supplier for vintage tires.
http://www.cokertire.com/
These people are the biggest supplier for vintage tires.
http://www.cokertire.com/
Automotive Network, Inc., Copyright ©2026
