Opinions on heads please?

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The Magnum R/T heads are the way to go. Personally I like the aluminum versions but the cast iron heads are just as good, just heavier.
 
Out of curiosity....What's the difference in engine performance and reliability between hydraulic and mechanical flat tappet lifters? Any difference in pushrod length or rocker arm style?
 
They are even reliability wise. Assuming of course they are broken in properly. Pushrod type (ball and ball, or ball and socket) and length are both affected, and with some hydraulic lifters (depends on the cam grind) and all solids you must have adjustability, so the adjustable rockers are a must.
 
i wouldnt even THINK about a solid cam for a everyday driver!!!...i dont even have a solid cam in my 340 duster that i street race with!!
 
Time to break it down:

360 block (zero decked, +.030)
Stock Crank and rods
KB107 +.030 Pistons
XE274H-10 230/236 dur.
.488/.491 lift w/ 1.6 roller rockers
RPM heads
RPM Air Gap intake
750cfm Holley
Internally balanced

Desktop Dyno puts this engine at:
10.6:1 compression and
392 hp @ 5500
407 ft/lbs @ 4500 without porting

( i used the flow specs from another thread on the board for stock RPM heads)

What do you all think? Pretty accurate? Under-rated or over-rated? I've seen similar builds on this board but no dyno ratings or 1/4 ETs for them?
 
One comment. If you are using 1.6 ratio rockers your lift will be well over .500". I am using a XE268H and have slightly over .500" with the 1.6 ratio magnum rockers.
 
Yeah, I think the dyno numbers are a little light, mainly because of the 1.5/1.6 rocker bit, The cam will effectively be bigger, in all aspects, with 1.6s. I think overall its a good package, and should top 400hp in the real world. A little cleanup on the heads, and I'd think 425 with no loss of torque should be in range, on pump gas.
 
I've got no qualms about using a solid lifter cam is a street car. My Duster has had a solid cam in it since the day I got it.

You can run more valve spring so the valves don't float as easily, you can get more lift per duration and they sound wicked too. So you need to adjust them once in awhile, big deal, you can't get the kind of performance I get from my engine with a hydraulic that's for sure.
 
i run a solid roller in my engine and its not a daily driver but not far away from being posible too use eweryday, biggest problem is gasprices..
 
At the moment I forgot how to calculate that. If I remember correctly, it's the difference from the center of the cam to the highest lift multiplied by the rocker ratio? I'll check my book tonight and re-calculate it.
 
Divide the lift at the valve by 1.5 then multiply the result by 1.6. In other words your .488/.491 at 1.5 is .520/.525 with 1.6 ratio rockers.
 
Well if you are going to nit pick it's .5237333333333333333 which would round off to .524. :)

I guess my fat fingers missed the 4 the first time!

Hasn't been discussed but the additional rocker ratio will increase the cams duration @ 0.050. With the XE cams having very steep ramps to start with it will likely only be a degree or two.
 
dgc333 said:
Well if you are going to nit pick it's .5237333333333333333 which would round off to .524. :)
Click to expand...

No, if you are a really anal nitpicker you go to comps website and get the actual lobe lift, which for the XE274H exhaust lobe is 0.327, and multiply it by 1.6 to give you 0.5232. :)

xe274h specs
 
Yes. still streetable. Just to be sure, you should be checking piston to valve clearance anyway, and using a degree wheel..
 
Hehe. Good enough for me. Future build is now set. Thanks a lot everyone for helping me out. I'm sure I'll have more questions once assemply and machining starts but for now, I gotta start researching where to buy things(and save a little more money).
 
I would only recommemd the Indy heads if you are looking to make 600 plus HP.
I run the Indy 360 -1 heads but i am putting out over 700 HP.
 
i went and grabed the magnum heads from the yard today $50. if you can use a roller cam you can use the lifters, and pushrods. you can use the la valve covers to make it look stock and drill and tap the intake it to the la. They made 400hp with a 318 with no porting a 500 lift cam and 10:1. ported they flow 270 or so. which is plenty for 500hp and up.

steve
 
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