stock camshaft specs.
- Thread starter Russ
- Start date
Howdy Back Russ:
I can tell you what I have, but it does not include what you're looking for.
Duration- 252 I/256 E, Int opens 7 btc, Int closes 65 abc, Ex opens 55 bbc, Ex closes 21 atc. Overlap 28 degrees, Lift .348".
I have never seen or heard of a .050" lift duration on a stock cam. Same for LSA. Short of measuring these dimensions yourself, I don't know where you find them. Given the characteristics of a stock '68 cam (high vacuum, smooth idle, good bottom, high durability), I'd say that the lift rates are pretty lazy and the LSA to be in the 114 range.
If anyone has this info, I'd sure love to hear it too.
Adios, David
I can tell you what I have, but it does not include what you're looking for.
Duration- 252 I/256 E, Int opens 7 btc, Int closes 65 abc, Ex opens 55 bbc, Ex closes 21 atc. Overlap 28 degrees, Lift .348".
I have never seen or heard of a .050" lift duration on a stock cam. Same for LSA. Short of measuring these dimensions yourself, I don't know where you find them. Given the characteristics of a stock '68 cam (high vacuum, smooth idle, good bottom, high durability), I'd say that the lift rates are pretty lazy and the LSA to be in the 114 range.
If anyone has this info, I'd sure love to hear it too.
Adios, David
After 1969, Ford phased n the 256 degree cam for newer V8's and 250 I6 sixes. It was a standard type off the shlef cam profile grind. All 1962 to 1968 Sixes and base model eights had the 252 degree cam, after that, it varied.
Coupe Boy or Mustang Geezer used to have the factory chart, but it didn't have the 50 thou figures. From Australias Crow cams and New Zelands Kelford Camshaft Shop, they show that there 254 and 256 aftermarket cams are up 20 degrees up on stock 50 thou duration, so that puts the standard age old Ford 252 and 256 cams into 50 thou figures of about 180 on the 252, and about 185 on the 256 on the non canted valve engines. Basically very, very mild.
The 1969 to 1980 250 cam has lots to recomend it, as you apparently loose no mpg but gain power and it still idles okay.
Any aftermarket street cam has to have at least 195 to maybee 205 degrees of lift at 50 thou to maximum lift in order to be worth a cam change. The peak at lash duration doesn't go far above 256 thou, and the duration at which both exhast and intake are 30 thou off the seats is kept the same for great beavoiur on the street.
They key component of a street cam is the amount of duration at 30 thou lift on intake and exhast. If its kept the same as a stock cam, you can run a very radical cam with no affect on low speed characteristics. Sadly, few people publish this data as it was a battle to get even the 50 figgures published. For a while, you'd get at lashj duration, then some cam makers would give you 20 thou figures. In the 80's, 50 thou figures depicted the intensity of the cam.
If a stock cam is only 256 duration, but has 185 duration at 50 thou, then it is less intense than a 256 duration cam that has 205 degrees duration at 50 thou. The cam basically lifting more intensley, then mees the same factor peak duration figures. There are cam profiles which are able to have a very soft intial lift to look after pushrods or lifter noise, then start comming on with lots of duration in the 30 to 50 thou lift afrea, then go to a moderate total lift.
Hope that helps
Coupe Boy or Mustang Geezer used to have the factory chart, but it didn't have the 50 thou figures. From Australias Crow cams and New Zelands Kelford Camshaft Shop, they show that there 254 and 256 aftermarket cams are up 20 degrees up on stock 50 thou duration, so that puts the standard age old Ford 252 and 256 cams into 50 thou figures of about 180 on the 252, and about 185 on the 256 on the non canted valve engines. Basically very, very mild.
The 1969 to 1980 250 cam has lots to recomend it, as you apparently loose no mpg but gain power and it still idles okay.
Any aftermarket street cam has to have at least 195 to maybee 205 degrees of lift at 50 thou to maximum lift in order to be worth a cam change. The peak at lash duration doesn't go far above 256 thou, and the duration at which both exhast and intake are 30 thou off the seats is kept the same for great beavoiur on the street.
They key component of a street cam is the amount of duration at 30 thou lift on intake and exhast. If its kept the same as a stock cam, you can run a very radical cam with no affect on low speed characteristics. Sadly, few people publish this data as it was a battle to get even the 50 figgures published. For a while, you'd get at lashj duration, then some cam makers would give you 20 thou figures. In the 80's, 50 thou figures depicted the intensity of the cam.
If a stock cam is only 256 duration, but has 185 duration at 50 thou, then it is less intense than a 256 duration cam that has 205 degrees duration at 50 thou. The cam basically lifting more intensley, then mees the same factor peak duration figures. There are cam profiles which are able to have a very soft intial lift to look after pushrods or lifter noise, then start comming on with lots of duration in the 30 to 50 thou lift afrea, then go to a moderate total lift.
Hope that helps
Russ, thanks to david & deano they have given you the true weakness of the stock ford camshaft.
The main consideration in camshaft duration is how much your compression is??
If you are in the 8-1,8.5 class all you need is a camshaft in the 194-204 degrees @ .050.
If your compression is over 9.5 then you can go for the 214 degrees @ .050.
If over 10.0 then you can go for a camshaft in the 224+ @ .050.
You want to keep your cranking compression over 175-195 #
This will give you the ultimate in performance.
Russ I know you just wanted stock camshaft specs, but the main point is don't use these old obsolete camshaft profiles.William
The main consideration in camshaft duration is how much your compression is??
If you are in the 8-1,8.5 class all you need is a camshaft in the 194-204 degrees @ .050.
If your compression is over 9.5 then you can go for the 214 degrees @ .050.
If over 10.0 then you can go for a camshaft in the 224+ @ .050.
You want to keep your cranking compression over 175-195 #
This will give you the ultimate in performance.
Russ I know you just wanted stock camshaft specs, but the main point is don't use these old obsolete camshaft profiles.William
Here's some stock cam specs from Accelerated Motion.
http://www.amotion.com/
COMPARE .050 Dur V.Lift Adv Dur Sep A.M. PART #
FORD 144/170/200/250 L6 - HYDRAULIC
1963-83 Hydraulic Lifter Set HT2083*12 ***
1963-83 Hydraulic Lifter Set - Hi-Rev HT2083R*12
1963-72 178/178 .371/.371 240/240 107 32621-18137
1969-83 184/185 .392/.392 254/255 109 32621-18573
194/194 .413/.413 256/256 108 32621-19641
195/201 .417/.433 249/261 109 32621-19842
202/202 .435/.437 266/267 109 32621-20344
207/208 .457/.439 265/283 107 32621-21079
212/213 .450/.451 278/282 109 32621-21378
When I originally saw this I surprised at the LSAs here. 107*
http://www.amotion.com/
COMPARE .050 Dur V.Lift Adv Dur Sep A.M. PART #
FORD 144/170/200/250 L6 - HYDRAULIC
1963-83 Hydraulic Lifter Set HT2083*12 ***
1963-83 Hydraulic Lifter Set - Hi-Rev HT2083R*12
1963-72 178/178 .371/.371 240/240 107 32621-18137
1969-83 184/185 .392/.392 254/255 109 32621-18573
194/194 .413/.413 256/256 108 32621-19641
195/201 .417/.433 249/261 109 32621-19842
202/202 .435/.437 266/267 109 32621-20344
207/208 .457/.439 265/283 107 32621-21079
212/213 .450/.451 278/282 109 32621-21378
When I originally saw this I surprised at the LSAs here. 107*
Howdy All:
The "stock" specs Jackfish listed from Accelerated Motion are NOT stock FoMoCo specs. They may be designing their version of a stock type replacement camshaft. FoMoCo used at least six different grinds in small sixes over the years ranging from the 1960 144 engines at 232 duration, .360" lift with an LSA of 111, to the later models of the 200/250 of 256 duration, .368" or .372".
Accelerated Motions "stock" replacement cams are clearly better then stock in lift.
Again, I have never seen lift specs for stock FoMoCo cams at .050". I guess it might be jig time. It is clear that the ramps on stock profiles are much lazier than equivalent duration performance profiles.
Adios, David
The "stock" specs Jackfish listed from Accelerated Motion are NOT stock FoMoCo specs. They may be designing their version of a stock type replacement camshaft. FoMoCo used at least six different grinds in small sixes over the years ranging from the 1960 144 engines at 232 duration, .360" lift with an LSA of 111, to the later models of the 200/250 of 256 duration, .368" or .372".
Accelerated Motions "stock" replacement cams are clearly better then stock in lift.
Again, I have never seen lift specs for stock FoMoCo cams at .050". I guess it might be jig time. It is clear that the ramps on stock profiles are much lazier than equivalent duration performance profiles.
Adios, David
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