With My XE262H Using Comp 981 valve springs, On stock 416's, Would I see advantage going to 1.6 Roller Tipped Rockers ? The Cam is Rated .469/.469 @ 1.5, If My calculations are correct, Ill come out with just about .500.500 @ 1.6, Wich is a bit bigger

I lack the mental fortitude right now to figure out the increase in duration, But My main question is, Would this be a worth increase with the stock heads, Or will I be better off sticking with 1.5 Roller Tips.

I am using the stock ones Now, and Have heard horror story's about their accuracy. ( Rb

Since the 1.6's and 1.5's are essentially the same price, I guess I really Want to Know weather or Not the 1.6's Will afford me more power, Not make a Differance, Or end up hurting me.


This is assumeing all intake, exhuast ect mods are Up to par, and the only Bottleneck would be the Stock 416 305 heads.


Thanks alot.




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60 Ranchero - Project ( Money Hole )
85 Sport Coupe LG4 - Daily Driver

Just another Hot Rod kid, or thats what they all tell me.
Livin' the Stereotype

 

I am pretty sure the 262 cam is 0.469 on the intake side and 0.479 on the exhaust. I don't have my spec sheet in front of me, but I am SURE it is a dual pattern cam... I have the same cam too. And I use 1.6 rollers, but I will admit I don't have stock springs, so I have no worries.

It has been argued if the increase in ratio doesn't increase the duration to any appreciable degree. I have no comment.

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1984 z28 w/ a 357 cu in. monster engine which is looking like the posterchild for Edelbrock with the exception of the Holley 750vac... all the suspension stuff... 9-bolt posi disk is in...

-=ICON Motorsports=-

 

There is an increase in ratio, but it is probably negligible. 2° - 3° would be my guess; basically you're changing the advertised duration from whatever it is at .006" (262 in this case) to whatever it would be at .005625"; and a similar change to the .050" duration. If the ramp was real gradual (think of a "151" cam) the duration might increase significantly, but those cams have real steep ramps so I doubt it's really an issue.

1.6s won't ever hurt, as long as your valve springs are up to the task (those should be). If your heads are in totally stock unported configuration then the gains from 1.6s will probably not be very great, since the port probably represents a bigger restriction than the amount the valve is opened. On the other hand, if the heads have had their bowls smoothed, there could be a whole lot more difference; in theory they could increase your HP by as much as 6.67% ((1.6/1.5 - 1) x 100%), which would be huge. That would be 20 HP on a 300 HP motor. In reality it's unlikely that they would make that much difference.

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"So many Mustangs, so little time..."
ICON Motorsports

 

You are probrably Right Blade, I was going off the Top of My Head.


I guess what I should ahve Said RB was that, By going to 1.6's, I wont be In Danger of effectivly "over Camming" my Motor ? Or more specifically, My heads.

Even if they Dont Show Much or any Gain over the 1.5's with these heads, A long as they don't Hurt performance, Then, Considering the identical cost, they Would be "investment in the Future" for when I get some real heads.


Am I right folks ? thanks.

" Measure Twice, Spend once "



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60 Ranchero - Project ( Money Hole )
85 Sport Coupe LG4 - Daily Driver

Just another Hot Rod kid, or thats what they all tell me.
Livin' the Stereotype

 

you would get a much better gain by pocket porting your heads. then the increased lift would be much more effective giving you a greater gain.

 

you should see improvement, but like odb said i'd look at head work before going with the 1.6 rockers

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ICON Motorsports

1st & 3rd
MM Black Diamond Lodge 538 F&AM

 

Chances are with that much lift you are going to see problems with retainer/locks-guide-seal clearance unless something has been done to the heads. Most of them can take about .480 before you run into clearance problems, but after that you better check first.

 

Thats Another Thing I was worried about Madmax. Maybe I Shoudl Find myself some Jyard 416's And go to Town On em First.

Thanks For all the educated opinions Guys.


Im toying with the Idea of building a low budget, Killer 305, Just cause I can




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60 Ranchero - Project ( Money Hole )
85 Sport Coupe LG4 - Daily Driver

Just another Hot Rod kid, or thats what they all tell me.
Livin' the Stereotype

 

Well if you are on a budget then run less lift

If the heads are on the car I would be really cautious unless you know exactly what has been done to them in the past. Probably with the lift you have now it would work best.

 

Yeah max, Im 99.9% sure they are completely Stock heads.


Just trying to develop a Purchasing Path that Will Give me the most Gain now And I wont have to buy The same stuff again later.

IE buying 1.5's Now and then when I get some real heads, buying 1.6's. Would Rather Just buy the 1.6's Now, even If I wont see any appriciable gain above 1.5 providing they will work and wont cause a decrease in performance.


See what I mean?

So I guess the next Question would be, Whats the max lift people are running On their stock 416's providing they are using the appropriate springs.



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60 Ranchero - Project ( Money Hole )
85 Sport Coupe LG4 - Daily Driver

Just another Hot Rod kid, or thats what they all tell me.
Livin' the Stereotype