myths about cams...
 

to day i drove 248 miles one way to get a head for my car and while i was there picking up my part and dropping off a set of seats me and tmckinney got to talking about cams and the measurement of them...

tmckinney had a dial indicator set up on one of his spare heads with the exhaust cam installed to measure the exhaust valve lift... he found something i think is good information... and could answer a lot of questions for some people and shred some information given on these forums...

first off when measuring one of his many exhaust cams he noticed a strange measurement... then showed me the same measurement... now i need to tell you that this man has forgotten more about cam set up and applications than i could ever know... and he has some straight advice and ideas about how to make these motors run...

but any way... he measure 348 lift on the stock exhaust cam on the head... full valve open and full valve closed... we have heard and i have said that the cams are 232 cams... well this information cannot be right when the lift on the cam measured 348... the 232 would have to be duration... and not lift as i have thought in the past... this also clears up why there is actually so little gain from adding aftermarket cams to the motor...

the lift on a jwt cam is 390 and duration is 270... that is not that big of a differance from the stock cams... and might be why there is so little performance gained out of building a ka24de motor in na trim...

im reading the fsm again to see if i missed the cam specs for the motor... but so far nothing states what the actual valve lift and duration is... i might have to check with the guy at nissan to get an answer for it if he has one...

but the dial indicator dont lie... and the lift measurement was there... now we just have to find out what the actual stock cam specs are... cus i now that what i thought is not right...

here is the link i got all of my fsm from...http://www.zeroyon.com/index/content/view/24/47/
if anyone sees something i dont please let me know... oh yeah the specs are under em...


p.s. ty i stole your lighter... im sorry i owe you one now...

i dont know if that info is correct either. the JWT S1 cams gave me a gain of 8whp on a N/A motor....and thats dynoed of course.

STOCK 91 Cams - Intake - 207 degrees duration @.050”, .350 lift; Exhaust 215 duration @.050”, .367 lift... this is taken from the pdm sight... so i am guessing that calling the cams 232 was wrong... im still going to check with a guy at nissan to be sure of the numbers...

keep us posted..

as soon as i get some more answers then i will have a lot of info in the cams that i am going to be having made for the 240... the company i use will keep the grind on file to recreate it any time it is needed...

this might take a few grinds to get the output i am looking for but i am willing to pay for the work if it gets me and other people the power we spend our hard earned money to get...

enjuku racing sells some more aggressive cams for around 480.. has anyone looked into these???

ifyou look at the enjuku specs they list them as being lower than stock cams... this is the problem i have found with all of the cams for the 240... for some reasn they spec their cams different than any other cam maker in the world... and then people who make cams for them spec them the same way... but the numbers that enjuku gives for the cams still dont have near enough lift or duration for what i am working on building... if there is not at least 475 lift then it wont do me much good...

ok besides your cam situation what do you think about putting a second exhaust cam in as an intake cam.. do you think it will produce a gain or just help the motor run better.. because ive heard of doing this in a s14 , but they gain hp because they come with less aggresive cams, what do you think about this is a s13?

adding 2 exhaust cams from a 91 to 93 into any dohc motor will increase power some yes... you are adding higher lift cams in place of lower lift ones... this is a suggestion i would say go ahead and do it... tmckinney is doing some more measurements on the stock cams to find the highest lift out of all of the cams 91 to 94 and 95 to 98... as soon as he has his measurements done im sure there will be a post on it or i will give the information he finds...

kool that will help.. i just thought hey im getting another motor ill pull the exhaust cam from it and put it in for a lil more oomf..(heard bout it with the s14s) so i was just wonbdering if it would work..do you still rotate it 4 degrees counter-clockwise?

not 4 degrees... 4 teeth on the timing chain... shearch n the topic there is another post that has a lot of info there bout it...

thats what i ment not degrees..teeth..so its the same for s13 as for s14 .. thats all i was aksing..