Performing cam upgrade...

[hunter_angler]

Mr. Stinker:

please keep us posted on your progress and results. I have been interested in a reasonably (whatever that is in Viperworld) priced integrated heads/cam/intake/TB package for a long time, and I am sure others are too. I know that excepting maybe the factory Gen IV castings (with their adaptibility issues in our Gen III trucks), the Strikers are the best N/A performance option, but $10K or so for just the setup heads, rockers and spacers you need is a mighty big hurdle. Sometimes makes me wish I was back in GMLSxworld.

Getting just close to the same performance level for under half that cost would be a real nice alternative. Thanks for your efforts.

 

[Tooloe]

when i had ART do my heads and cam i gained about 50-55RWHp with ported heads and cam..... but then again i'm still on the stock manifolds if your going to do it make sure you get headers i know it choking my truck down.... i fully believe that if you doa good heads an cam set up with headers you can pick up 125 easy....

 

[rottenronnie]

....the Strikers are the best N/A performance option, but $10K or so for just the setup heads, rockers and spacers you need is a mighty big hurdle. Sometimes makes me wish I was back in GMLSxworld.

Getting just close to the same performance level for under half that cost would be a real nice alternative. Thanks for your efforts.

You are around $2600 too high..

Strikers (assembled), roller rockers, hardened push rods, cutting for desired compression $6895; plus $500 for valve cover spacers: $7395 total.
Actually the Strikers alone are $4500 but you still need the offset roller rockers (shaft-mount) to go with them. and those drive the price up.

There are cheaper alternatives out there (including the spacers) for sure, it all depends what YOU want..

The o.e.m. heads will have their limits (of course) and that is why the same guy that designed those, designed the Strikers.

Ronnie

 

[hunter_angler]

You are around $2600 too high..

Strikers (assembled), roller rockers, hardened push rods, cutting for desired compression $6895; plus $500 for valve cover spacers: $7395 total.
Actually the Strikers alone are $4500 but you still need the offset roller rockers (shaft-mount) to go with them. and those drive the price up.

Ronnie

Thanks, Ron. I stand corrected. Had it in my head that the heads alone were $7K plus. :stupido2: Maybe just a rich quote from one of your competitors.

 

[Tooloe]

ronnie.. how much can you really get out of the stock heads? you seem like you know alot of info on heads an cam set ups for these things.... i'd like to go a little bit more with my heads.. not not sure if it's worth the money... they have a light port an polish job nothing fancy

 

[bclark05]

Would be nice if it where a little less expensive. These sound awsome with a bigger cam.

 

[Ironhead]

when i had ART do my heads and cam i gained about 50-55RWHp with ported heads and cam..... but then again i'm still on the stock manifolds if your going to do it make sure you get headers i know it choking my truck down.... i fully believe that if you doa good heads an cam set up with headers you can pick up 125 easy....

heads
cam
long tubes
its really about 65 to 75 tops ,,,this weekend i plan on installing bbk tb,and stinks coils and wires ,,,will be tickled pink if i can bag 525rwhp on next dyno

i had one fine port and polish job done ,,had a bit of struggle with springs ,,and a compititon cam 270 ,,,i dynoed 501rwhp ,,that was with bassani shorties and high flow mids from justin,,

next will be done with mopar long tubes,catless,BBK TB,,Stinkmans coils/wires,,looking at a different cam ,,just cant pull the trigger yet

 

[bigredv10]

Has anyone tried porting there own heads? from what ive read in hotrod magazines and what not its considered an "art" and there is a right way and a wrong way. I figure just smoth the surface get rid of bumps and edges then match your intake,gasket and head together, is this a bad idea? maybe practice on a chevy? :dontknow:

 

[Fahrenheit]

heads
cam
long tubes
its really about 65 to 75 tops ,,,this weekend i plan on installing bbk tb,and stinks coils and wires ,,,will be tickled pink if i can bag 525rwhp on next dyno

i had one fine port and polish job done ,,had a bit of struggle with springs ,,and a compititon cam 270 ,,,i dynoed 501rwhp ,,that was with bassani shorties and high flow mids from justin,,

next with be done with mopar long tubes,,BBK TB,,Stinkmans coils/wires,,

When and where....

 

[Tooloe]

heads
cam
long tubes
its really about 65 to 75 tops ,,,this weekend i plan on installing bbk tb,and stinks coils and wires ,,,will be tickled pink if i can bag 525rwhp on next dyno

i had one fine port and polish job done ,,had a bit of struggle with springs ,,and a compititon cam 270 ,,,i dynoed 501rwhp ,,that was with bassani shorties and high flow mids from justin,,

next with be done with mopar long tubes,,BBK TB,,Stinkmans coils/wires,,

o well in that case.. i made 527 on motor first pull then heak soaked it made 507 .. so i guess i should be happy lol i had greg god do my heads an cam and they seem to work together great!

an BigredV10 i've thought about doing this porting just the stock manifolds.. my heads are 100% gasket matched to everything.. so i know the manifolds are choking it down

 

[JTS VENOM PERFORMANCE]

Mr. Stinker:

please keep us posted on your progress and results. I have been interested in a reasonably (whatever that is in Viperworld) priced integrated heads/cam/intake/TB package for a long time, and I am sure others are too. I know that excepting maybe the factory Gen IV castings (with their adaptibility issues in our Gen III trucks), the Strikers are the best N/A performance option, but $10K or so for just the setup heads, rockers and spacers you need is a mighty big hurdle. Sometimes makes me wish I was back in GMLSxworld.

Getting just close to the same performance level for under half that cost would be a real nice alternative. Thanks for your efforts.

I will

I'm not going to get into a technical conference with ronnie, he is a truely good guy:rock:
but also a dealer for striker heads, which to me is jsut alot of money for most folks to deal with , ours will be reasonably priced with good gains i suspect.
if not mistaken viper9233 cant remember his sig name, but got 550 range with ported heads, cam and rockers.
I know with my truck , bone stock with no tuner, reg cab, no cats made 440 ish, so that dont leave too much to make our goal, one of the keys is correct head porting , so big red leave the dremel alone and a correct cam configuration.

 

[rottenronnie]

... Maybe just a rich quote from one of your competitors.

Yes, maybe so...
Glad to see you are still around !!...

Ronnie

 

[kyle's srt10]

I will

I'm not going to get into a technical conference with ronnie, he is a truely good guy:rock:
but also a dealer for striker heads, which to me is jsut alot of money for most folks to deal with , ours will be reasonably priced with good gains i suspect.
if not mistaken viper9233 cant remember his sig name, but got 550 range with ported heads, cam and rockers.
I know with my truck , bone stock with no tuner, reg cab, no cats made 440 ish, so that dont leave too much to make our goal, one of the keys is correct head porting , so big red leave the dremel alone and a correct cam configuration.

Vipertruck2933 (Tim) made 535/567 :rock:

 

[JTS VENOM PERFORMANCE]

Vipertruck2933 (Tim) made 535/567 :rock:

thats right my bad, 535 which leaves 65hp to the 600 mark

 

[rottenronnie]

ronnie.. how much can you really get out of the stock heads? you seem like you know alot of info on heads an cam set ups for these things.... i'd like to go a little bit more with my heads.. not not sure if it's worth the money... they have a light port an polish job nothing fancy

Tooloe-

Greg Good has a loyal following.

Yours is a bit of a loaded question. If you are talking about how much flow, that is one issue. If you are talking about how much power, that is another and the two don't always go hand in hand. Gaining flow is important but is NOT everything. When I started with this stuff a number of years ago, I thought it was. So in my mind (back then), if pure stock, Head X flowed 250 c.f.m. on the intakes and ported they could flow say, 275 c.f.m. they would just HAVE TO make more power...right? Absolutely Wrong!
For example, the floor of the Intake port (or the short turn as it is commonly called) is one area that is quite touchy to changes. Flatten it slightly with a grinder and flow numbers can really start to rise, bringing on the "WOW" factor. However in a wet flow situation, with gasoline being heavier than air, air and fuel will shear and part ways (literally) in a badly shaped port. Liquid fuel doesn't burn so the flow-bench measured an increase in flow but actually the QUALITY of flow suffered. The net result was a decline in power!
I have taken a practical approach in addition to dyno and track results if there is a question..- Pull the heads off and LOOK at the actual burn pattern to see if the porting worked or if there is room for improvement. On a poor porting job, you can actually see unburned areas (sometimes massive areas) on the piston top and the matching area in the combustion chamber where fuel wash has taken place in this situation/example. Just like it sounds, the fuel has cleaned/washed the piston top (still silver) and the head, and no combustion has taken place. Lower combustion efficiency is lost power, it's that simple.

On the flow side, I've heard claims about how much flow can be obtained with the factory heads and even by porting a pair of Strikers. I can believe the claims to a point but sometimes they get out of hand. And in the worst cases, they simply aren't true at all and can even turn out to be considerably worse than an untouched head...
References are sometimes made comparing the o.e.m. heads with the Strikers and that is fine but sometimes because they are a benchmark, they are also somewhat of a target. Like I mentioned, the original Viper heads and the Strikers were designed by the same individual and his credentials are beyond reproach. He saw limitations in the o.e.m. heads and designed a superior head in the Striker. That in itself is saying something important and should be considered....

Unfortunately, raw flow numbers are used to sell ported cylinder heads, almost exclusively. It is somewhat of a trap, however.

Anyway, are there power gains to be made on the factory heads?
Well, considering the Gen III heads are factory ported versions of the Gen II heads, they have already been re-worked and are already decent. However, because they are mass-produced and not on a zillion dollar auto, YES they CAN be improved over the stock Viper heads. Is it worth working on a set of o.e.m. heads- Yes, definitely.
Are they going to OUTPERFORM an off the shelf set of Strikers? No, they aren't.
Will PROPERLY ported o.e.m. heads be "good enough" comparing them to the results obtained by Strikers? THAT is the question that is up to the individual. Going with PROPERLY ported o.e.m. heads can be a less expensive way to go and the power difference between them and Strikers may not be worth the added expense to some individuals.
A realistic gain with PROPERLY ported GEN III heads would be 65 wheel + 20 more with a cam. I was super impressed by the results obtained with the Strikers and roller and picked up a distributorship because of it. I just wish I had the time to work more with the combination..it was more or less an experiment: Bolt them on, add a small cam and see what happens..I went from 423 to 566 wheel (through the cast iron manifolds) and a whopping increase in torque (607). And from 13.8 ETs to 12.5s at 3000 feet.

As a side note, I appreciate what Stinker is doing and my comments were my opinions and not to discredit Tony in any way. That is something I have absolutely ZERO interest in. I have spoken with him on the phone a few times and he seems genuinely enthusiastic about this stuff and works hard to help others and keep prices more than reasonable. If he comes up with a relatively low cost N.A. power improvement, which I'm sure he will, it might certainly be worth a look.

For those that want to take it to another level however, Strikers are available...decisions, decisions....

Hope this helps ©

Ronnie

 

[Tooloe]

Tooloe-

Greg Good has a loyal following.

Yours is a bit of a loaded question. If you are talking about how much flow, that is one issue. If you are talking about how much power, that is another and the two don't always go hand in hand. Gaining flow is important but is NOT everything. When I started with this stuff a number of years ago, I thought it was. So in my mind (back then), if pure stock, Head X flowed 250 c.f.m. on the intakes and ported they could flow say, 275 c.f.m. they would just HAVE TO make more power...right? Absolutely Wrong!
For example, the floor of the Intake port (or the short turn as it is commonly called) is one area that is quite touchy to changes. Flatten it slightly with a grinder and flow numbers can really start to rise, bringing on the "WOW" factor. However in a wet flow situation, with gasoline being heavier than air, air and fuel will shear and part ways (literally) in a badly shaped port. Liquid fuel doesn't burn so the flow-bench measured an increase in flow but actually the QUALITY of flow suffered. The net result was a decline in power!
I have taken a practical approach in addition to dyno and track results if there is a question..- Pull the heads off and LOOK at the actual burn pattern to see if the porting worked or if there is room for improvement. On a poor porting job, you can actually see unburned areas (sometimes massive areas) on the piston top and the matching area in the combustion chamber where fuel wash has taken place in this situation/example. Just like it sounds, the fuel has cleaned/washed the piston top (still silver) and the head, and no combustion has taken place. Lower combustion efficiency is lost power, it's that simple.

On the flow side, I've heard claims about how much flow can be obtained with the factory heads and even by porting a pair of Strikers. I can believe the claims to a point but sometimes they get out of hand. And in the worst cases, they simply aren't true at all and can even turn out to be considerably worse than an untouched head...
References are sometimes made comparing the o.e.m. heads with the Strikers and that is fine but sometimes because they are a benchmark, they are also somewhat of a target. Like I mentioned, the original Viper heads and the Strikers were designed by the same individual and his credentials are beyond reproach. He saw limitations in the o.e.m. heads and designed a superior head in the Striker. That in itself is saying something important and should be considered....

Unfortunately, raw flow numbers are used to sell ported cylinder heads, almost exclusively. It is somewhat of a trap, however.

Anyway, are there power gains to be made on the factory heads?
Well, considering the Gen III heads are factory ported versions of the Gen II heads, they have already been re-worked and are already decent. However, because they are mass-produced and not on a zillion dollar auto, YES they CAN be improved over the stock Viper heads. Is it worth working on a set of o.e.m. heads- Yes, definitely.
Are they going to OUTPERFORM an off the shelf set of Strikers? No, they aren't.
Will PROPERLY ported o.e.m. heads be "good enough" comparing them to the results obtained by Strikers? THAT is the question that is up to the individual. Going with PROPERLY ported o.e.m. heads can be a less expensive way to go and the power difference between them and Strikers may not be worth the added expense to some individuals.
A realistic gain with PROPERLY ported GEN III heads would be 65 wheel + 20 more with a cam. I was super impressed by the results obtained with the Strikers and roller and picked up a distributorship because of it. I just wish I had the time to work more with the combination..it was more or less an experiment: Bolt them on, add a small cam and see what happens..I went from 423 to 566 wheel (through the cast iron manifolds) and a whopping increase in torque (607). And from 13.8 ETs to 12.5s at 3000 feet.

As a side note, I appreciate what Stinker is doing and my comments were my opinions and not to discredit Tony in any way. That is something I have absolutely ZERO interest in. I have spoken with him on the phone a few times and he seems genuinely enthusiastic about this stuff and works hard to help others and keep prices more than reasonable. If he comes up with a relatively low cost N.A. power improvement, which I'm sure he will, it might certainly be worth a look.

For those that want to take it to another level however, Strikers are available...decisions, decisions....

Hope this helps ©

Ronnie

wow lots of info there ronnie thanks for typing it up!... man your right... time to make a move hahahaha. thanks for the explanation sir... but so i under stand this correctly heads are kinda like cams just cause they are big an choppy doesn't mean they perform well ..."To much flow isn't always a good thing" i get what you are saying about the burn pattern also my heads will be coming off the truck soon i'll have to check it out... now i'm kinda curious

 

[scoobert]

I will

I'm not going to get into a technical conference with ronnie, he is a truely good guy:rock:
but also a dealer for striker heads, which to me is jsut alot of money for most folks to deal with , ours will be reasonably priced with good gains i suspect.
if not mistaken viper9233 cant remember his sig name, but got 550 range with ported heads, cam and rockers.
I know with my truck , bone stock with no tuner, reg cab, no cats made 440 ish, so that dont leave too much to make our goal, one of the keys is correct head porting , so big red leave the dremel alone and a correct cam configuration.

larger valves would not hurt either. if ya make them titanium with a good set of springs i believe you could raise the red line too.

 

[rottenronnie]

wow lots of info there ronnie thanks for typing it up!... man your right... time to make a move hahahaha. thanks for the explanation sir... but so i under stand this correctly heads are kinda like cams just cause they are big an choppy doesn't mean they perform well ..."To much flow isn't always a good thing" i get what you are saying about the burn pattern also my heads will be coming off the truck soon i'll have to check it out... now i'm kinda curious

Yes, match the cam with the heads for best results; That is why, with completely stock heads, a cam changed by itself doesn't give a lot more power (because the o.e.m. heads and cam already are a pretty close match). Of course there are other things to consider (compression ratio being one of them) when you are choosing a cam. But if you aren't making any big changes to the engine, a head and cam match is a good way to go. So if you can get more flow at a higher lift with your head mods, for example, go with a cam that can take advantage of that.
I went with a cam that would produce lots of torque instead of top-end horsepower because of the drain with the automatic and the fact my truck is staying full-weight. A guy with a lighter reg cab (and a stick of course) or a Viper car can go with a bit more aggressive grind (with the same setup), without a penalty.
You are also restricted somewhat by the e.c.u. in that a cam with lots of overlap (narrow l.s.a.) will raise hell with vacuum and low speed will be really rich. That can make it way less than fun to drive and it will also accelerate engine wear due to constant oil contamination.

Ronnie

 

[rottenronnie]

Hi,
Early last year, Tony from JTSVP started a thread to provide members information about camshafts. It was in a question and answer format. Rather than taking the time to think it all through again, I just copied and pasted the information and some of the answers to questions that were asked. It is long and some have maybe seen it before, but it may provide some additional info. for those that are interested, while we are on this topic.

Ronnie


Terms: Provided by JTSVP-

LIFT: The cam's basic function is to open the valves. Lift refers to how far the valve is opened (or lifted) off its seat. A street performance cam will usually have between .450- and .550-inch lift. More lift can increase power, and increased lift without changing duration increases power without affecting the point of peak power on the rpm band. The rocker arms have a direct effect on lift because they don't have a 1:1 lever ratio. A cam that has .318 inch of lobe lift (that's how far it lifts the lifter) will open the valve .477 inch with 1.5:1 rocker arms (.318 x 1.5 = .477) and .508 inch with 1.6:1 rockers.

Generally, a stock engine will tolerate .500-inch lift before the valves hit the pistons or the valvesprings hit coil bind, but any time lift is increased, these clearances should be checked.


DURATION: Duration is how long the cam holds the valves open. It's expressed in degrees of crankshaft rotation (remember, the cam rotates at half the speed of the crank). A 280-degree-duration cam holds the valves open longer than a 260-degree-duration cam. Holding the valves open longer allows more air and fuel into the engine and also allows more to get out through the exhaust. Longer duration (higher number) improves top-end power but almost always sacrifices low-end torque. Lower duration improves low-end torque and makes the car idle better, but it limits top-end power, and you can get only so much valve lift with a short duration cam due to the rate-of-lift limitations of the lifter. Roller cams, which we'll discuss below, have the advantage of allowing high rates of lift with relatively short duration.

The confusing thing about duration is the difference between "advertised" and "at .050-lift" duration. At .050-lift duration is measured from the point where the cam moves the lifter up .050 inch until .050 inch before the lifter is all the way back down. Most cam manufacturers differ in where they start and finish measuring for advertised duration. Some start at .004-inch lift, some at .008-inch and some measure it somewhere in between. That's why the .050-lift numbers are the best to go by. A 280 cam (advertised duration) from one manufacturer could actually have less at-.050 duration than a 278 cam from another, due to the different points at which the companies measure advertised duration.

LOBE SEPARATION ANGLE: This is the relationship between the centerlines of the intake and exhaust lobes. A 110-degree lobe separation angle means that the peak opening points of the intake and exhaust lobes are 110 degrees apart. This is ground into the cam and can't be changed without changing cams. Lobe separation angle is another way of expressing overlap, which is the term formerly used by cam manufacturers. Overlap is the amount of time that both valves are open in the same cylinder. When both valves are open at the same time, cylinder pressure drops. A cam with 106 degrees of lobe separation angle will have more overlap and a rougher idle than one with 112 degrees, but it'll usually make more midrange power. END JTSVP
Thanks Tony Mahn!!

Provided by RottenRonnie-
... generated from some of the questions..

How much lift should a cam have?-

If the heads hit peak flow, say 300 c.f.m., @.585" lift, you could choose a cam and rocker ratio that provides a total lift of .600" at the valve. Much higher than that punishes the valve train for no real good reason, because the port can't move anymore air/fuel with a higher valve lift than that anyway. Cylinder head flow numbers at values less than maximum lift are also worthy of study. Keep in mind the valve is only at maximum lift for an EXTREMELY short time.

Flow gains in well designed heads (like the NASCAR guys use) concentrate flow improvements in the mid-lift range which will provide usable power over a wider r.p.m. range. I'll put in a plug for Strikers here because they have pretty significant gains in flow in the mid-lift area. So, while peak flow at MAX lift is a guide, it doesn't really tell the whole story.

Compensating for a weak exhaust port with a cam-
Also, you could compare the head's Intake Port with the Exhaust port (a ratio) and have the cam ground to match that. So say the exhaust port flowed 25% less than the intake, you could add more duration to the exhaust side of the cam to help compensate. So you may end up with an Intake Duration Number like 230 degrees @ .050" lift but an Exhaust Duration of 242 degrees @ .050" lift. That would hold the Exhaust valve open longer to help out the poorer flowing exhaust port. You could also increase lift on the Exhaust Side to help out the port as well.
As you may have read before, we won't get much of a power improvement by ONLY changing the cam when using the o.e.m. Viper heads, because the cam & heads are a pretty good match already.

Affects of Overlap-
Increasing overlap (a tighter lobe separation angle, which is lower numerically) will create a peakier power band that tends to kill torque (cylinder pressure) down low and then creates more power (cylinder pressure) once the r.p.m. is high enough to move the column of air THROUGH the engine, in the normal direction.
When an engine is idling and the piston is still rising for the very last part of the Exhaust stroke, during overlap (just when the intake also starts to open) the column of Intake air (and fuel) can be pushed back up into the intake manifold. Then it goes back into the port again towards the cylinder, once the piston descends enough to encourage flow. The boogety-boogety idle sound is because the airflow from the intake into the cylinder isn't yet stable enough to flow in one direction. So it bounces back and forth until the r.p.m. climbs (somewhere above idle) and inertia helps carry it one way (into the port and cylinder), the chaos diminishes and the engine smooths out. As r.p.m. rises, during w.o.t., engine power (torque) typically climbs until max r.p.m. is reached and somewhere before that point, maximum cylinder pressure, or Peak TQ. is achieved.

Increased Overlap effects vacuum readings as well (they are typically lower) because, when the I & E valves are open at the same time, the engine sees atmospheric pressure. It is camshaft overlap that can make an engine harder to tune, particularly with a supercharged application. If the camshaft "phases" (maximum cylinder pressure) at the SAME time the supercharger has built maximum boost, cylinder pressures can skyrocket. That is prime time for detonation to develop unless measures have been taken (reduce ignition timing, richen the A/F mix, or BOTH) to curtail it.

The reason for overlap is as follows: Somewhere (based on cam design) before the piston reaches the bottom of it's POWER stroke, the exhaust valve opens. As the piston starts to rise again, somewhere before it reaches the top, (again based on cam design), the intake valve opens. This is when overlap is happening, and what overlap is- BOTH valves are open at the same time, in the same cylinder. The more overlap, the longer the intake and exhaust valves are open at the same time. Anyway, the reason for this is because the exhaust gasses are leaving the cylinder and that column of gasses assists (pulls) the column of air and fuel coming INTO the engine through the open intake valve. This is all happening before the actual intake stroke, when the piston descends and the exhaust valve finally closes. One high-overlap trade-off is a lumpy idle (but I like it anyway!) The trick here is to encourage the fresh intake charge into the cylinder without letting too much of it exit through the open exhaust valve.

Side Note- Header primary pipe sizing.
Well designed headers help prevent excess scavenging (when the Air & Fuel that is supposed to stay INSIDE the cylinder to produce power, leaves with the exhaust). This is where header pipe diameter that is too big (even a bit too big) can really screw things up. Something called Rarefaction occurs: This is when a sound wave during the exhaust stroke hits the collector then bounces back UP the primary header pipe towards the cylinder to block and prevent the fresh intake charge from leaving the engine, unburnt. If primary sizing is off, the timing of this event will be as well. But again, this is another topic...

In the end, if you are in the process of choosing a cam- It is always a good idea to check with the company grinding it for you, for their recommendations...

This is quite condensed considering the topic but...

Hope this helps ©

Ronnie

 

[blackviper]

Great info Ronnie. Thanks.