XPBaller

Well i took the engine apart and discovered it has a comp cam XE 276hr..... But it also has 1.6rrs. I know that the xe276 is "designed for use with 1.7s". I was wondering how the 1.6s are effecting this cam, if at all, and if it would be worth it to switch to 1.7s?



thanks guys.

Portmaster

Switch to the 1.7's if you want to use this cam. or if you are not crazy about the cam move into another grind.

XPBaller

Thanks a lot for the reply portmaster. your input is always appreciated [=

but, if you could, answer a few more questions for me?


Like i said, i didnt know that it had this cam or the 1.6s in it until i took the engine apart because the mains were wiped out, and i just remembered seeing on summit and on the forums the cam was designed for 1.7s. This cam was ran for an uncertain amount of time on 1.6s.... was that harming anything as far as wear goes?

And - id like to keep the cam, it seems to pull like crazy so id rather not waste money on another cam when what i have is already good..

If its designed for 1.7s, then swapping from 1.6s to 1.7s should wake it up that much more, right?

Also, Will I need to change anything else other than the rocker arms obviously when swapping the 1.7s in (like pushrods or shims) or will it just be a direct swap?

Lastly, I read somewhere that the XE line of cams was designed to be installed dot to dot. So, should i just install it straight up or should i breakout a degree wheel?


VERY MUCH APPRECIATED

FivePointOhh

break out the degree wheel! a friend(also a member here) just installed a xe274 cam in a fox and had to degree it 6* advance to even get it to the specs on the cam card. dont just do dot to dot. always break out they degree wheel.

Portmaster

It didn't hurt anything to run the 1.6's on your car. It's always a good idea to break out the degree wheel. Im MY personal experiance and with over 1200 engines under my belt I haven't seen a cam in the last 15 years 6 degrees off. I'm sure it's possible but with a really good chain it's rare to have to move more than 2 degrees. Most went in straight up. Most of the time I advance or retard a cam to move the power around and not to get it in spec on the cam card. If I was using a really good chain and my cam was 6 degrees off the mark they would be sending me another cam. You can pick up an inexpensive degree wheel from Summit or Jegs and you can get a mag base dial indicator from someplace like Harbor freight and you can make your own piston stop from and old spark plug and bolt and a poiter can be made from an old wire clothes hanger. You can get out for less than 50 dollars and you will have it next time you need it.

XPBaller

Thanks guys.. ill probably just install it straight up and call it good.. but you never explained to my why this cam needs the 1.7s.. i understand it increases valve lift but why would the cam call for a 1.7?

I guess ill change rocker arms, but Will I need to change anything else other than the rocker arms obviously when swapping the 1.7s in (like pushrods or shims) or will it just be a direct swap?

mjr46

my custom cam was right on the money, never seen one 6 degrees off???

Joel5.0

The ONLY way you will be sure the camshaft in your setup is within specs, is by doing a cam degree (or the lift at TDC method, if provided). I have installed a "few" cams and they have been from exact, to ±4°.... which one is your case? Best suggestion from me?.... don't guess, measure and set it correctly.... that's the correct way to do it.

Since you have an OTS generic cam designed for 1.7 rockers, you may even want to test (if possible) what a split rockers setup would make performance wise. 1.7 intake/1.6 exh. or vice versa..... in your case, and not even knowing the heads you have installed, you might want to check the 1.6 I/ 1.72 E alternative first. LUK

XPBaller

I know what heads i have, theyre edebrock performer RPMs with 1.9 intake valves (ferrea valves), with what looks like a dual valve spring of some kind. I dont really feel like fooling around with split ratios like that, its either gonna be 1.6 or 1.7 rocker ratio all the way around, but since the cam is designed for 1.7s i will probably do like portmaster said and be making a switch to those.



nobody answered my question about swapping the 1.6s to the 1.7s. Is it gonna be a direct bolt on swap or am i gonna have to change other things too?

Joel5.0

You need to check for the correct PR length and valve train geometry.