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Discussion Starter #1
Hey,

I was going to go with the X-303 Cam and new Ford Racing Roller lifters.. I don't have the money for a Solid Roller cam and lifters.
But I know you can use a Flat tappet Cam in a Roller block..
So should I go ahead with the X-303 Cam. or Go with a nice Solid Lifter Flat tappet..! my buddys think I should go with a Solid cam they think it will rev harder and Make more Horse power..

what do you think?? Hyd. Roller or Solid Flat.!!!!



Thanks,
 

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If you have aftermarket rods etc to support spinning it to 6500plus you can do pretty well with a flat tappet solid. If you have a stockish bottom end, the hyd roller can rev as far as it's safe to go anyway. I shift mine at 6200 (when I do it right):rolleyes: but it hangs in there until the 6600 revlimiter when I don't.
 

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Discussion Starter #3
I don't have to have Aftermarket Rods and crank to spin it 6500 RPM.. . My Rods are reconditioned with ARP Bolts.. Crank is Turned and everthing is balanced.. It will take 6500 No problem.

I don't know if the X-303 cam will spin to 6500 though
 
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Of course you can turn it that high, but what is the point if you passed your power peak a couple thousand rpm ago. Well maybe extra wear on the bearings and rings. Sounds great.:barf:
 

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wrong... why would you be past your power peak if your cam and intake matched? :confused:

you can build a 302 with stock heads that will make peak power at 7500rpm... you wouldn't want to as it would cost you a fortune, but the point is that the heads don't really dictate where you make power... granted, bigger heads are better for higher RPM, but your camshaft and the wave harmonics of your intake manifold are what dictate where you make power...

put a huge solid cam in an engine with big heads and a monster ported Performer intake and don't be supprised when the thing wants to shift at 6000rpm and doesn't run the way it should

Forrest
 

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Your carb, intake, and heads are will determine if you can use that cam. On a 306 the X cam will make power clear thru 6500 with no problem. It will suck on the street, but will sound cool. hope you got auto and a stall converter.
The roller cam is the way to go, if you can find the spider, and dog bones out of a junk yard block, and buy some new stock roller lifters (they're pretty cheap). If you don't have a roller block, I think all you have to do is get a reduced base circle cam.
Otherwise probably the best thing to do now is get a cam custom ground for your setup, talk to this guy http://www.flowtechinduction.com
Another thing to do is have the lifter bores bushed, use the link-bar roller lifters from a chevy roller block, and get the right pushrods.
 

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speaking from experience, mildly ported stock heads are good for anchors at 6500 to 7000. What good is your intake if it outflows your heads?
 

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well, it can sorta act as "plenum", but I was really just trying to make the point that heads don't necessarily dictate powerband... cam/induction wave harmonics do...

Forrest
 
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stinkin' Lincoln said:
wrong... why would you be past your power peak if your cam and intake matched? :confused:

you can build a 302 with stock heads that will make peak power at 7500rpm... you wouldn't want to as it would cost you a fortune, but the point is that the heads don't really dictate where you make power... granted, bigger heads are better for higher RPM, but your camshaft and the wave harmonics of your intake manifold are what dictate where you make power...

put a huge solid cam in an engine with big heads and a monster ported Performer intake and don't be supprised when the thing wants to shift at 6000rpm and doesn't run the way it should

Forrest
Big cam and stock heads=matched. NOPE. Did he say he had a lightweight racing internally balanced engine. DOUBLE NOPE. Of course the intake should match, but that wasn't where you were going with it originally. You said big cam + stock heads = high reving. C-Ya. Done with this one.
 

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talk to Buddy Rawls... unported 289 heads on a 9.5:1 289 engine with a Victor Jr. intake... making 350+ hp... tell him small heads don't work...

tell the NMRA factory stock guys running 10's on unported E7's with 300+ degrees of cam duration not to run big cams... :rolleyes:

nice sound arguments though! :blam:

Forrest
 

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Although E7TE heads are allowed, they aren't mandatory in NMRA Factory Stock class racing. These are also allowed.
1) Stock Ford OEM 5.0 HO Cast Iron Cylinder Heads. (*Deduct 250#)

2) FRPP/SVO GT-40 Cast Iron Cylinder Heads

3) FRPP/SVO GT-40P Cast Iron Cylinder Heads

4) Stock Ford OEM 4.6 GT 2 Valve or 4 Valve Cobra Cylinder Heads.

5) FRPP/SVO 4.6 2-valve


As for running 10's.... Not the case. The record is still in the upper 11's unless they had an event last weekend and nobody mentioned it!! :lol:

Factory Stock record holder: Justin Burcham 11.72 8/11/02
@ 115.54 mph 8/11/02

Small chambered heads aren't the worst thing in the world, but it isn't the greatest idea to use E7's with a large cam. The heads can make a difference. They will make a difference if you have too much cam and induction for them. It's kinda like filling a pot with water and then adding more water. It overfills and you end up with a mess. Stock heads can only flow (maybe) 220 with a maxed out effort on the intake side, but porting is not allowed in factory stock anyway. Then again, I think the cam has to be "factory stock" as well.
 

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Base Weights:



ENGINE POWER ADDER MAX CI WEIGHT

5.0L None 311 3300

4.6 2V None 289 3000

4.6 4V None 289 3375



Deduct 250 lbs for Ford OEM Stock 5.0 HO heads.

Deduct 50 lbs for Automatic Transmission.

Note: All weights are with driver at conclusion of run at scale area.
 

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Discussion Starter #16
Hey,

Well my combo is going to be.....

306. It was a factory Roller motor. DSS Racing Forged Pistons,
Stock Rods Recon. with ARP Bolts. Stock Crank turned, Balanced,
Performer RPM Intake gasket matched, 650DP, C-4, 3500 stall, reverse valve body, converter, 4.10 gears in the 8.8, 28'tires, alum. underdrive pullys.

351W DOOE Heads, 60cc chambers, Portandpolished, Roller rockers and guideplates, I might be going with some World- windsor SRs though not shure yet...

I'm thinking I'm either going with the X-303 cam, or the Z-303 cam for the Duration.. Do you think this combo with either the X-303 cam or the Z-303 cam Spin 6500 RPM?? I think it should pull to 6500 pretty hard... This Truck is also going to be Tubbed..
Think it will run 12s? weighs about 2750 pounds...
 

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not trying to argue, but you would really be hard pressed to get a 7500 rpm hp peak in a stock headed set-up, the flow is just not there and the port velocity is too high at that rpm for the stock cross-section. the flow capability will diminish substantially at that velocity (choked flow). I just finished a 435 hp 289 that made peak hp at 6800 (solid flat tappet)and it was a real rip snorting piece, but limited in rpm due to its track requirements, but it did have very nice ported stock heads. the SS set-ups are typically in the 7500. They are running .700+ with 275-285 @.050 on the intake. but for the better flowing casting (like c5ae-b) the NHRA allowance is pretty generous 155cc's on the b head. most others are in the 140-144 range, so even they are some pretty well set-up stock configured heads, but they are not the real screamers and will make peak hp in the 7000 range.

there was a comment about 'big cam+stock head= matched (nope). that is partially incorrect. the only way to get a restricted motor to breath is thru the valve evnts. This takes a lot of ramp and area under the lift curve. you cant just throw any big cam in there, but big cams that are correct for the motor's requirment trends are going to make the motor work very well. i guarantee a big cam intended for the restricted set-up (not even a perfect match, but just follows the trends of the motor's needs) will really make the motor come alive.

restricted inlet does not need much exhaust help in the form of increased or early exhaust valve events. and truly you if you stick to that relationship, you can almost throw as big of intake lobe at it you want at it and will continue to respond.

if you dont think a small headed does not respond to ramp rate and higher durations, then you only have to look at the street warrior/trophy stock set-ups. granted its not normally a 128cc head, but it is still a reasonably small head (GT-40 and P heads are around 140cc).

then on top of the the stock eliminator cars are living proof of what it takes to make a small head really run.

the goal is not to drive a stock eliminator on the road, I realize. It is possible to have a very low 12 second ET stock headed 302 that makes peak hp around 5500-6000, and still has outstanding low end. No 2500 pound lightweight tricks either!, I have seen it done regularly over the years and have done it myself. mid-upper 12's with stock heads are really sweet, considering lots of aftermarket headed set-ups still struggle to break in the 12's

Buddy rawls
 

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Discussion Starter #18
Thank Buddy..

Do you think my combo with run 12s Bud??

Also being you grind cams.! What can should a run the X-303 or the Z-303? I'v heard that the Z-303 blows the X out of the water.? Sorry I just can't Aford one of your cams right now.! :(
 

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Thanks Buddy,

You just went a little further with what a couple of us were saying. It's not "all about flow" in general, but when using stock heads, the more flow you can get, the better(pot of water overfill). I wouldn't be expecting a 6500plus peak with stock heads either. They just aren't ready for it, but any 351W head will help, and the GT40P isn't bad either, when using iron heads.

My brother ported a set of 86 factory heads and with those (and other mods), the guy who used them ran [email protected] in his coupe. Of course, this car weighs about 2700 w/ driver (he won't admit that), but it's proof that stock heads, while a limiting factor, can produce enough power for 12's easily enough. I managed [email protected](best) with stock E7 heads and a rather small split duration cam, several years ago. I also had an Edelbrock Perf.5.0, but the mass air, etc, was still stock at the time.

306, I can see your car easily running 12's with 1.84 valved W heads, and probably even if they aren't ported. With todays cam selection, you may want to look into getting an NON-Ford cam for this car. I am sold on split durations personally, but there are many, "not too expensive" cams to choose from that may be better for your application.
 

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I am sorry I got so wrapped up in the small head thing (which I dearly love!!!). the original question of solid roller versus a solid flat tappet. unless there is a specific reason why you want to run a mech roller, such as to be competitive in a class or to attempt the total maximum capability of a set-up (at the maximum limit), a solid flat tappet is a very cost effective alternative. there are some flat tappet lobes that will easily rival some of the medium (with respect to ramp rate) solid rollers.

even in the hydraulic world a flat tappet can be pretty sporty. granted a hyd roller can provide a better ramp than a flat hydraulic, but the weight savings alone and increased rpm (with very basic equipment) can easily force a look to the hyd flat tappet.

One particular set-up ran in the mid 10's using a cam that was truly virtually identical to the 280H magnum from 280/280, 230/230,110. really decent idle and extreme low end grunt that could grab 1.40 60' times without a transbrake.

I am just trying to let people know that aside from the break-in crap, a flat tappet is very effective camshaft. solid or hyd. and for street car with a choice between a solid roller or a solid flat, the solid flat should get the nod 99% of the time.

also on the non-roller blocks, forget trying to accommodate a hyd roller, stick a flat tappet in it and ride to your heart's content.

Buddy
 
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