Comp cams xe268h for 318

[dartfreak75]

I know this has been done to death but I need quick answer and I'm not having any luck in the search bar. I have a stockish 318 stock bottom home ported "302" heads 340 intake 600cfm carb and headers stock stall with 2.76 gears. I found a really good deal on a comp cam xe268h cam I know it's a little large but would this cam work good and be an improvement would it be to big and hurt more than it helps? Here are the specs if your not familiar with it. I have a couple different cams in mind but ran across a good deal and thought it may just be worth it.

 

[mderoy340]

To big IMO. 2.76 gear will hurt you. Look at the XE256 or XE262 or equivalent duration in any brand for a better fit. Go solid lifter if you have adjustable valve train, today's hyd lifters are a crap shoot.

 

[krazykuda]

Throw in a set of Rhoades variable duration lifters and it will work fine with the 2.76 gears...

I ran a stock 340 cam with 268/276 duration with Rhoades lifters and 2.76 gears with no problem and no bogs....

Read the second article for info on how they work...

Articles

 

[Hellrats]

I tried that cam with a stock converter, it's to big. It will be a turd.

 

[toolmanmike]

I agree with all. If you don't use Rhoades lifters you need a higher stall converter and a 3:23 gear (at least) for it to work well.

 

[dartfreak75]

Ok thanks guys I kinda thought the same I thought I better ask this cam was not my first choice I will list the ones I'm looking at and get you alls input. One more question about the xe268h first tho how would it perform with 3.73 gears stock stall? The only reason I ask about this one is I found it on Ebay new (preowned but unused) for 89 bucks buy it now!! If someone could use it you should buy it it's a heck of a deal!

 

[toolmanmike]

Ok thanks guys I kinda thought the same I thought I better ask this cam was not my first choice I will list the ones I'm looking at and get you alls input. One more question about the xe268h first tho how would it perform with 3.73 gears stock stall? The only reason I ask about this one is I found it on Ebay new (preowned but unused) for 89 bucks buy it now!! If someone could use it you should buy it it's a heck of a deal!

Better but still not good. The gears will get you in the power range faster but a bigger cam won't idle at 650 rpm in drive that the stock converter. Performance converters do 2 things, They allow the engine to accelerate from a stop close to or in the power range of the cam and they do slip at a higher rpm so a rough idle cam can idle around on the street.

 

[dartfreak75]

Ok so here are the other cams I'm looking at there are just so many and they seem similar I'm having a hard time deciding. Since I first started my search I have learned so much from you guys. I now know about the dcr and scr and didnt understand the lsa thanks for that! Ok so for a street engine in the comp cams would you high energy or extreme energy? I'm also looking at the luniti voodoos. Ok on the the good part here is a few that I'm looking at which one would you pick for this setup feel free to recommend your own but only within the same price range please dont recommend a 300 hundred + cam my price limit is around 150 but Hopefully less Haha. And also I have hydraulic flat lifters and stock rockers.

 

[rumblefish360]

That cam (268) should require a converter stall of 2500 for street duty and use a min. of a 3.55 gear ratio. Any less of the two above and you will run into problems.

 

[rumblefish360]

Of the cams listed above, 218@.050 is the largest I would go with a stock converter and low numeric gears. Under 3.00 ratio.

 

[dartfreak75]

Of the cams listed above, 218@.050 is the largest I would go with a stock converter and low numeric gears. Under 3.00 ratio.

Ok thank you that is very helpful that will help norrow it down!! Will a cam 218@50 and smaller still perform the same with lower gears? I have a 8.8 with 3.73 packed away I plan on using later but I want to run my 2.76 for now so I want to choose a cam that will work well with both but most definitely not loose with the 3.73 if that makes sence I'd rather get a cam that will increase performance with a lower gear than loose since that is gonna be my permanent gear eventually.

 

[rumblefish360]

No, it’ll perform better since lower numeric gears is adding torque but it does shorten top end speed.

 

[toolmanmike]

Ok thank you that is very helpful that will help norrow it down!! Will a cam 218@50 and smaller still perform the same with lower gears? I have a 8.8 with 3.73 packed away I plan on using later but I want to run my 2.76 for now so I want to choose a cam that will work well with both but most definitely not loose with the 3.73 if that makes sence I'd rather get a cam that will increase performance with a lower gear than loose since that is gonna be my permanent gear eventually.

I would do the rear end swap now and the cam later if it were me. You will be surprised how snappy those 3:73 gears will be compared to your 2:76's. I went from 2:73's to a 3:23 Sure Grip and haven't even put my LD4B and Edelbrock on yet. LOL

 

[rumblefish360]

Agreed. Purchase the e-bay cam for later.
Do the rear end first.
Purchase converter/install.
Then do the cam.

Purchase pain killer for the perma smile

 

[dartfreak75]

Thanks here are a few more. These are comp xe and luniti voodoo all under 218@50. This is so hard idk how you ever decide lol after a while all the numbers start blurring Haha!! One thing that will help narrow it down is springs I plan on using melling 1120 vs.

 

[rumblefish360]

Your plan was to use a certain spring before a cam was chosen?

OK, being honest and point blank, that’s freakin some stupid *** stuff right there.

Choose the cam, purchase matching springs from the company or go to PAC for your springs and have the info for them ready.

 

[dartfreak75]

Your plan was to use a certain spring before a cam was chosen?

OK, being honest and point blank, that’s freakin some stupid *** stuff right there.

Choose the cam, purchase matching springs from the company or go to PAC for your springs and have the info for them ready.

Ok well that's fine I havent purchased the springs yet so that's ok. If you remember I already purchased a different cam and everyone here told me it was a bad choice for my combo so I started over! I'm just trying to choose the right one the 2nd time around to not waste anymore money!

I would do the rear end swap now and the cam later if it were me. You will be surprised how snappy those 3:73 gears will be compared to your 2:76's. I went from 2:73's to a 3:23 Sure Grip and haven't even put my LD4B and Edelbrock on yet. LOL

That is a good plan but my engine isn't running no cam at all lol I'm trying to get this thing on the road. I can't afford to rebuild the rear and get a Tc and build the engine it's just out of my grasp. So I just want to build the right engine now and then later when I cam swap the rear it will be that much more rewarding.

 

[dartfreak75]

Your plan was to use a certain spring before a cam was chosen?

OK, being honest and point blank, that’s freakin some stupid *** stuff right there.

Choose the cam, purchase matching springs from the company or go to PAC for your springs and have the info for them ready.

What cam would you choose?

 

[rumblefish360]

What cam would you choose?

You may not like my choice, but....
This would be my pick for now and later though it will be a little sluggish off the line. The gears in the 8.8 later will liven this up really well. XE262H-10.

 

[rumblefish360]

Hummm, missing some of the post above. Bouncing around screens to much. I want to add;

“Oh! Your so singing my song on not enough money and wanting to drive the ride. I SO hear ya brother! I hear ya. I’m currently stuck between a rock and a hard place. UGH!

 

[dartfreak75]

Thank you. That one was one of my top picks!! In your opinion would the melling springs work for that cam or would the. Comp 901-16 be a better fit.

Hummm, missing some of the post above. Bouncing around screens to much. I want to add;

“Oh! Your so singing my song on not enough money and wanting to drive the ride. I SO hear ya brother! I hear ya. I’m currently stuck between a rock and a hard place. UGH!

Thanks bud man I really screwed up from the beginning to be honest I should have formulated a plan came here asked questions and came up with the best combo. My original plan was to just throw a stock 318 in drive it but I wanted to refresh it with new gaskets so I bought gaskets then I got to reading how a 4bbl was pretty much pointless with a stock cam so i thought wth it's already apart I will put a cam in it so I bought one. The cheapest one that summit had. Then everyone here told me it was a bad fit so I decided to listen now I'm thinking my carb is a bad fit for the combo it just keeps adding up! At least now I know to ask first buy later thus the creation of this thread Haha!! Next time around I will know better create a plan and freaking stick to it!!! I am almost to the point of just starting over just create a new thread and a new build starting with what I have and figure out what I need next. It's like a putting together a puzzle that has 5 different boxes in one. Haha lol it's just part of the fun tho I'm loving every second of it.

 

[rumblefish360]

In your opinion would the melling springs work for that cam or would the. Comp 901-16 be a better fit.

I answered that above... ;) ... the companies matching springs is what I would look at first. They have done the work and have packages grouped for the KISS method.

Thanks bud man I really screwed up from the beginning to be honest I should have formulated a plan came here asked questions and came up with the best combo. My original plan was to just throw a stock 318 in drive it but I wanted to refresh it with new gaskets so I bought gaskets then I got to reading how a 4bbl was pretty much pointless with a stock cam so i thought wth it's already apart I will put a cam in it so I bought one. The cheapest one that summit had. Then everyone here told me it was a bad fit so I decided to listen now I'm thinking my carb is a bad fit for the combo it just keeps adding up! At least now I know to ask first buy later thus the creation of this thread Haha!! Next time around I will know better create a plan and freaking stick to it!!! I am almost to the point of just starting over just create a new thread and a new build starting with what I have and figure out what I need next. It's like a putting together a puzzle that has 5 different boxes in one. Haha lol it's just part of the fun tho I'm loving every second of it.

Well, if you not having fun......
And yes, changing the plan is expensive.
A 4bbl. On top a stock 318 isn’t much of an increase. Once you get the package together, the little engine wakes up.

 

[nm9stheham]

I'd recommend the XE256 with what I see right now.

But I would like like to know the complete list of other mods you have planned. Once you make a lot of mods then re-visit. The larger cam don't do much for you if you don't have all the matching parts to take advantage of it.

If you can live with some sub-optimal performance for a while as you wait for the subsequent mods, then maybe a larger cam is a good choice. However, you know how the 'best laid plans of mice and men' sometimes don't work out LOL

 

[dartfreak75]

So from what I'm seeing. Y'all prefer the xtreme engine over the high energy?
So do y'all think I should start a new thread on my build and just start over or just do it here?

 

[rumblefish360]

IDK, it seems like A good start here. Missing the compression ratio and actual head work & specs....

Yes, the split duration cam has an edge on a stock head. The porting work would have to show a good balance between intake and exhaust ports to consider a single pattern cam. Generally a slightly off balance in the exhaust flavor would allow a single pattern cam into the picture. Otherwise, most times, not every time, a dual pattern shows it self better.