need a new cam to bring the rpms down

[project89]

can somone run a cam sim for me, when i built my motor i went with a 268/272 duration cam on a 115 lsa.

well ive been having to spin this thing to 7,400-7,800 rpms.it made it threw the season alright and didnt hurt anything but for next year id really like to bring the rpms down to something more reasonable say 6,800 rpms max

i was thinking something around 264/268 on 115 or 116lsa verses playing with the cam timming on the current cam

would like to know what kind of difference it would make in the power band

[geoffinbc]

What kind of cam is this? Roller or flat, hydraulic or solid?

[project89]

What kind of cam is this? Roller or flat, hydraulic or solid?

opps sorry its a hyd flat

[gectek]

less dur keep the LSA wide from 112 - 114...as much lift as the heads will handle, meaning both with springs/pressure and with how much lift the head will take before the port flow goes static...plus advertised is a bad way to buy a cam really...look at .050 best way to tell you how it will behave.

[ArtosDracon]

I'll be happy to run it for you, just need to know what engine this is in, what heads it has and the fully set of specs for the cam.

[geoffinbc]

That's not an aggressive cam at all. The Crane 272 cam usually wont rev like that. Is the cam installed straight up? Is there any advance ground into the cam from factory.

Any how your doing this on hydraulic lifters is amazing.

[SappySE107]

Got a dyno sheet showing your powerband?

[project89]

no dyno only track testing and datalogs.

the motor likes to turn rpm the higher i rev it the faster the car goes, the cam was a mix of 2 popular supra cam grinds i went with the larger on the ex side and its been working really well.

the lifters were modified by my uncle for me i dont know exactly what was done to them but i can find out,

i can tell u at idle the valev train is quiet noisy but once rpms come up its quiets down, i think i actually have a vid somewere were u can hear it ill take a look

i think im just gonna drop back to a 260-2 cam since i already have one,but im kinda woried about power droping off considerably with it the cam is only really good for mild boosted aplications. granted i have yet to se ehigh boost other then a few highway test pulls but i think the 260 would actually hurt the motor once i got boost into the 18-21+psi range

[SappySE107]

How is a 272 cam a mix of 2 popular supra cam grinds, and what does a supra engine have to do with your iron head 60V6?

[project89]

the cam is a dual pattern cam its specs come after a supra hks 272 and another hks cam int/ex

supra has nothing to do with an iron head 60* motor but it never looks to other motors for specs and things they are trying

and u know what it worked quite well too

betterthan missed ur post
its not a crane 272 cam
no advance ground into the cam

and i asked my uncle about the lifters he said he enlarged the oiling hole slightly but thats it

[TurboGTU]

I had the crane 260, spun up well up to 6K rpm. Peaked power at about 4.5K rpm but still had plenty at 6K rpm. But this was with the stock hydrolic lifters and a ported head on the 2nd gen aluminum MPFI engine. Stock 1.5 rocker arms. THink the powerband would go up to 5k-5.5K rpm if the intake was rpm happy as the 3*00. Don't know if thats too much of a down step for you.

IF you have the grind I think you have, then at .05 lift you have a duration of 230/232. Great cam, but a real screamer. Its a 4500-8K rpm cam. Try a 224 duration of the supra grinds.


I THINK your uncle did the lifter trick of almost making the lifters solid by making them anti-pump up and just prelading them almost solid. Some old hot rodders used to shim them and keep a .01 to .02 free play on the plunger with out a spring in the lifter or loaded spring. Still hydrolic but not as solid as the solid lifters or as quiet as the stock lifters.

[project89]

ur dam close cam was to be about 4,500-7500 ish rpm range. and it does pull all the way up.

the combo of the cam,converter,gears works great in my car.
4,500 stall 9 inch converter, 4:10 rear gear , and a 28 inch tall tire
even though i know the combo works well, its only a matter of time before spining the motor to 7,500+ catches up and something fails.

[project89]

also which brand supra cam are u refering to on the 224 grind ??

[geoffinbc]

If your getting 230/232 duration at .050 with 268/272 advertised duration than that's one hell of an aggressive ramp.

Typically if you have a cam with 230 duration at .050 your going to see advertised duration above 275 but usually in the 280 range. For engines with larger lifters like Chrysler's and Buick's they can be more aggressive than a small block sized lifter which is what we are running.

[TurboGTU]

The grind I saw was mechanical. Try the T202-B or something in that range.

http://www.camshaftshop.com/camshafts/search_results.php?search_filter=keyword_and&search_string=toyota