650 rwhp and 7000 rpms on 488 cid

V10TT

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<FONT COLOR="#ff0000" SIZE="1" FACE="Verdana, Arial">This message has been edited by xsmph on 09-18-2002 at 06:06 AM</font>
 
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Julio -

I'm aware of the car you are in question of...

Making 650 rwhp for an 8.0 engine should be very obtainable, especially with the modifications you described. With the appropriate tuning, the car should make that and more. Although, you need to discount the rule of thumb (typical Viper vs. this Viper) in terms of peak power levels. A lot depends now on the cam profile and the tuning ability he now has with the replacement PCM. Given the proper amenities allows a whole world of capabilities.

Regards,
Doug
 

treynor

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For the amount of money which must have been involved, I'd prefer a 540 or 550 ci stroker engine making the same power at 5400 RPM. Much more torque, more driveable, and likely considerably cheaper.

Of course, for that much money I'd rather have a 790 RWHP DLM car, but that's a different story entirely...
 

MES

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Tell him to come to Moroso on the 15 and lets see it in action
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V10TT

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Mes, I think he will be there on the 15th. Nitorus ready and all .. 400 shot too dual stage w/ a direct port fogger.
I'd like to see what it runs..
Judging by the number it should trap in the low 130's on motor and 150 on juice... We'll see
I was under the impression the Viper intake with its cross ram design was no good for high rpm breathing... I guess the cam is the limiting factor then..
 

Supra

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Julio, is this the car?
http://forums.corvetteforum.com/zerothread?id=365701

1100 RWHP on NOS!

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by xsmph:
Mes, I think he will be there on the 15th. Nitorus ready and all .. 400 shot too dual stage w/ a direct port fogger.
I'd like to see what it runs..
Judging by the number it should trap in the low 130's on motor and 150 on juice... We'll see
I was under the impression the Viper intake with its cross ram design was no good for high rpm breathing... I guess the cam is the limiting factor then..
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V10TT

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yeap, that's the car,

<FONT COLOR="#ff0000" SIZE="1" FACE="Verdana, Arial">This message has been edited by xsmph on 09-18-2002 at 06:08 AM</font>
 
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V10TT

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1bad, I hear you..loud and clear

<FONT COLOR="#ff0000" SIZE="1" FACE="Verdana, Arial">This message has been edited by xsmph on 09-18-2002 at 06:08 AM</font>
 

Supra

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Gotcha, keep us updated. That thing should run some great times, and some sick MPH!

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by xsmph:
yeap, that's the car, But nobody has seen the dyno on it, I can assure you that!
It is all speculation now. The guy who posted that did so 2-weeks ago, and the car was still being tuned with eh Motec. I don't think it has been sprayed on the dyno at all...
Supposedly is a dual stage 400-450 shot of juice..
The info is probably what he heard.. these guys don't want anybody to know what's up.. we'll see at the track, and the mile-n-hour!!
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Just wondering, some hydraulic lifters can be modified to
give 'close to solid lifter high rpm advantage' and still
leave a little pump-up for hydraulic effect. I've modified
lifters on V-twin Harley motors - basically it involves adding a steel insert, which 'almost' eliminates pump-up. This way-
no machine work, and less dependent on oil pressure on the high
end.
 
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V10TT

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on the viper in question the block was machined for the soild lifters.. so no going back to hydraulic...
 

HP

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Solid lifters, for anything but racing, would be a nuisance
to me. Even though it's hard to hear anything over most
of our exhausts, I have an aversion to any extra pinging in my
motor, and sure as hell don't want another thing to have to
adjust on a regular basis. Plus, now days, the better tolerences that go into hydraulic lifters, make them more reliable and less likely to bleed down at the wrong time.

Is our spell check broke, or is my computer just not able to
make it respond?
 
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V10TT

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I think that the Vipers got such a big motor, and can make insane amoutnts of power at low rpm, and where designed to do so.. Whay change the Nature of the Beast?


<FONT COLOR="#ff0000" SIZE="1" FACE="Verdana, Arial">This message has been edited by xsmph on 09-18-2002 at 06:08 AM</font>
 
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I don't know why you guys have such an aversion to solid lifter cams. There is no law that states you have to run a cam that is too big for the application when a solid cam is chosen. I think a 250 @.050" or larger cam, whether a hydraulic or a solid, is too big for a street car. Comp Cams offers solid roller cams that are as small as a hydraulic roller cam. For instance, they have a solid roller lobe that is 230 @ .050", is 153 @ .200" for those of you that are concerned with good ramps, and it has .612" net valve lift, which is plenty. This is comparable to their 230 @ .050" hydraulic roller lobe that is 152 @ .200" and has .635" lift. Now here's the kicker, the solid roller lobe is only 268 degrees of advertised duration versus 282 for the hydraulic roller. This, combined with the fact that you can "tune" a solid cam by setting the lash tighter or looser makes a solid cam MORE streetable(idles BETTER)than a hydraulic cam of the same duration @ .050". And they make more power.

About "Valves MUST be adjusted often", all I can say is that if the valvetrain is set up corectly this is not the case. If the rocker arm geometry is correct, and the springs and cam match one another then the valve lash will remain very stable. The thing that I see that contributes the most to the lash moving on a racing engine is valve float. How often the valves have to be set depends on the miles driven and HOW HARD. I know drivers that are so ******* engines that they could tear up an anvil in a sandbox with a feather duster
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. If it's a daily driver and you're foot is always in it I wouldn't recommend a solid cam. You will have to set the valves more often than the weekend warrior who doesn't put a lot of miles on his car and shows a little respect for the engine. Just as an FYI, Winston Cup engines routinely turn over 9000 rpm (on the straightaways)for 500 miles with the same lash setting. That is 2000 trips down the 1/4 mile. Not too shabby for a solid, eh?

I see three advantages to a solid cam. One is that I can run slightly higher spring pressures and keep the engine out of valve float which makes more power and prolongs the life of the valvetrain. The second one is that a solid can make slightly more power and idle a little better than a comparable sized hydraulic. And the third reason, and I'm surprised no one has mentioned this with all of the talk of oiling systems in this thread, is the fact that with a solid cam you can restrict the oil supply to the top end and keep it where it is needed, the bearings.
 
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Look, you are blaming the solid lifter design for your poor performance when in fact it was the size of the cam, not the type, that was the problem. Had you chosen a HYDRAULIC cam that was 254 @ .050" you're low end performance and streetability would have been EVEN WORSE. You had a cam that was simply too big for your application, that's it. Please do not try to discredit solid lifter cams based on poor cam selection. Your criticism of solid lifter cams based on your single experience with them should be changed to caution of picking a cam that is too large. (Edit: I'm sorry. I thought you had written that you had run a solid cam. I re-read all of your posts and see that you haven't).

Besides making more power, road racers run dry sump oil systems because they maintain oil pressure better than a wet sump system through the turns. It has NOTHING to do with having solids or hydraulics. It has to do with the lateral forces that are placed on the car during the turns. Wet sump systems are terrible for road racing. And I'll state it once more, a solid lifter cammed engine that has the top end oil restricted has more oil on the bottom end than a hydrualic cammed engine. Now please tell me how that is a bad thing.
 
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Ok, I went back and re-read all of your posts in thsi thread. Now, since I'm open minded and also the kind of guy that likes to know "why" something "is" maybe you can help me with these questions. Especially since these questions are based on some of your statements in this thread. I think that it is important that accurate information be posted here on this board.


1. Why do pistons for a solid roller have to be custom made?

2. Why must the valves be adjusted "often"? What is your definition of "often"?

3. Why is a 10 throttle body manifold specifically recommended for a solid but not a hydraulic?

4. Why does a properly chosen solid roller cam have to be turned over 7000 rpm to make power?

5. Why would a properly chosen solid roller cam suffer from a loss of drivability and vacuum?

6. Why does a Viper engine with a solid roller cam require a dry sump system where it does not with a hydraulic cam?

Thank you.
 
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What I'm reading from all of your posts is that: solid cams = bad, hydraulic cams = good. It should read: Big cams are bad, smaller cams are good, for the street. Most of the points you are bringing up(loss of drivability, piston to valve clearance, Motech computer, etc.) against the use of solid cams are related to the SIZE of cam needed to make power at high rpm, not whether the cam is solid or hydraulic. The problems you list are associated with cam DURATION. You seem to be of the opinion that all solid cams are big, and therefore not streetable. This isn't so. If you have two street cams of the same duration @ .050", one hydraulic, the other solid, the solid will perform better.

PEER REE UDD.


The ONLY undesirable thing about a solid cam on the street, THAT IS SIZED CORRECTLY FOR THE STREET, is that the valve lash has to be checked periodically. You do not HAVE to run 10 throttle body injectors, OR custom pistons, OR turn over 7000 rpm to enjoy the better throttle response, power, and longer valve train life of a solid cam. Those things along with a dry sump oil system go with a high rpm, more power per cubic inch combination, regardless of the type cam used.

The hydraulics have problems with valve float. The hydraulic roller lobes offered by Comp Cams and others have some very aggressive ramps on them and we can't really run the required amount of spring pressure on them because lifter noise will set in. There is a limit to how much spring pressure a hydraulic lifter will tolerate. The solids don't have this limitation. In my line of work I see the problems associated with valve float. The bent exhaust valves, the intake seats that are pounded into the head, etc. How much power can you make with leaking intake seats and bent exhaust valves?

Would I recommend a solid cam for the average Viper owner? Nope, due to the fact that the valves have to be run from time to time. And I'm not posting on this thread to advocate the use of a solid on the street for anyone except the guy that is willing to do the extra work to maintain the engine. The guy that is willing to learn how to set valves, or pay to have it done, can get more perfromance from a solid than he ever would with a hydraulic.

About dry sumps. Racers run dry sump systems because they make more power and make the engine live longer. It has nothing to do with the cam. If anything, a hydraulic cammed engine needs a dry sump system more than a solid cammed engine because the hydraulic setup requires more oil to function. With a dry sump system there isn't 10 or 12 quarts of oil sloshing around in the oil pan to get whipped into a bubbly froth by the crankshaft, which hurts power and reduces bearing life. With a dry sump you are able to pull a vacuum on the crankcase, which lets you run low drag oil rings that have less friction, which makes more power. If you blow an engine you're not going to dump 10 or 12 quarts of oil out onto the track, a safety concern. You maintain oil pressure through the hardest turns.

And I don't know where you get the opinion that high rpm power won't run on the street. It can and does. Everyday. All the guy has to do is gear it and drive it right. Do Vipers have eyes? Can they tell when they are on the street, or the drag strip? If that guy with 650 rwhp has his car geared correctly, and the engine makes high average power, and he shifts the thing where it needs to be, in other words all of the things required to make a good pass down the track, he would clean your clock, street race or drag race.

If I were you I would leave this guy alone
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<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by 1bad gts:
Greg your STILL missing the point of the thread. I am not debating the fact that you can run a SMALL SOLID CAM in a street car with success. BUT YOU CAN NOT make 650 to the tires(with 488CU ) with a SMALL solid cam(the size you mentioned) thus you have to go bigger, MUCH BIGGER and that is when problems arise. As per Dans post running a BIG solid cam on a streetcar (THE SIZE needed to make 650 to the tires) is not worth the aggreviation.

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Now we're getting somewhere. So solids are not as bad as originally suggested, just don't run one that's too big for the application. I can live with that.

I agree that a huge cam is a burden on the street and it would be right near impossible to make 650 rwhp with a 488 and a small cam. But evidently this particular guy is willing to make the necessary sacrifices to be more competitive.
 
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<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by 1bad gts:
Greg about the comment about Vipers not being able to tell if they are on the street or strip PLEASE RELATE that comment to this particular thread and the size cam needed to make 650 to the tires on 488 cubes.Are you trying to say that a solid cam of the SIZE NEEDED TO MAKE 650 to the tires whose PEAK power is made over 6500 rpms is a good choice for a street driven VIPER used to drag race.Please also provide a torque-driveability profile of THIS CAM (not some much smaller )in point.

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It is related to this statement that you made earlier:

(quote from 1badgts) "just because the Viper makes more PEAK power on the dyno DOES NOT meen it will be faster in a street/dragrace type situation .I would venture to say (based on my bad experience with the 254 duration hyd cam) that with a solid cam you will not see any significant power until WELL over 5000 .RPM (NOT THE BEST APPLICATION FOR A STREET /dragrace car)" (end of quote)


Streetability is a see-saw. It is also relative. What the 650 guy considers streetable is obviously not streetable to you. It's a matter of opinion. There is no law for defining streetable, except for emissions standards, which I doubt he can pass with a cam that big. But that doesn't matter at the street races because you're not the EPA, and can do nothing about that. He is willing to endure rougher idling, poor vacuum, more expense on related components like a Motech to get more power so that he can beat guys that are not willing to put up with the hassles of a big cam (you).

My point about Vipers not having eyes is that as long as the car is geared right and driven right, it will run fast on the drag strip OR the street. The CAR doesn't know the difference between the two. Do YOU think it does?. You simply gear and drive the engine in it's appropriate rpm range. Anytime we make the engine breathe better the rpm where the engine makes peak power usually moves up. But not always. Some mods will increase power within the original power range. But heads and cams usually move the power band up. Sometimes you have to make a driving change as well as a gear change to use the extra power. What's the big deal with that? So he has to turn more rpm. So it's harder on bearings. That's understandable, and holds true for any engine. I don't know about this guys shortblock and I don't think you do either. Maybe he had a good engine builder. Maybe the builder performed some mods to the oiling system that will help it live longer. We don't know. It's his problem. As long as the car gets there first he wins, even if he has to coast through with a rod hanging out of the oil pan.
 
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I think this guy has achieved something noteworthy. I'm interested to know if the 1/4 mile times for this car are in line with the power it makes on the dyno, if anyone knows. Who knows, we might be pretty impressed.

1badgts, you have been bashing this guys car a lot on this thread. First about his selection of cam, then his power curve. I'm not sure why that is. This may sound silly, but does it bother you that someone is making more power with a stock size engine than you are? I hope not.
 
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<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by 1bad gts:
COME ON GREG,if a customer came to you and wanted to run a 650 lift ,270 plus duration cam in a STREET DRIVEN VIPER what would you tell him.Yes everyones defination of the word streetable is different but running a cam this size (once again the size needed to make 650 to the tires on 488 cubes )is CONSIDERED FULL RACE for a reason .Regardless of the gearing a cam of this size is going to be a complete PIG down low, NO VACUME at all with ABSOLUTELY HORRIBLE DRIVEABILITY.In the end i dont care what the dyno reads tell me what trap speeds he is running in the quarter.Like i said before i have had many Different size cams in my car Bigger with bigger dyno numbers was not always faster in the quarter.To put up with the kind of nonsence he is going to go thru he had BETTER trap in the 136-137 mph range or it is not worth it.

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I'm sorry dude, but your car is not the standard by which all other cars are judged.

There are street cars of all makes running around with cams as large as you're talking about. By the way, how do you KNOW the size of the guys cam anyway? How do you KNOW it is 270 @ .050" or bigger? You don't know. It could be much smaller than you think. And since you haven't made 650 to the tires you can't honestly say how much cam is required, can you?

This is turning into something unproductive so this is where I'm getting off.

I'm not buying your superincumbence.

edit: By the way, you don't need to repeat your horsepower and mile per hour to me. I am thoroughly familiar with them. I would place the odds of finding that information in any given thread on this board at about 5 to 1.
 

ronviper

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Blk2kgts, did you really mean 8's or was that a miscue. I believe it will take alot more than just power. Traction is a given but so is shifting a stick car at those rpm, as we all no vipers break lose very easily. I am seeing Albert's car which is unbelivable but he is still also a second from the 8's. That said good lucky with your project and don't let nobody piss on your parade, keep the faith.
 
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I most certainly would like to be kept up to date on your car. I'm very interested in it because you have put aside what many think of as "normal" for a street Viper and forged ahead. We're all just trying to learn here. I appreciate any input you may have. I am particularly interested in your heads and the cam you are running and what the drivability is like. I haven't had the opportunity yet to put a set of my heads on a solid lifter car with a Motec. All of my stuff has been with small, hydraulic roller, computer compatible cams.

I know 1badgts means well. I like his input also and read all of his posts since his car also runs very well indeed. Like I said, we're all just trying to learn here.

Keep up the good work.

Greg Good
 
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V10TT

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I had a chance to ride in the car outside the track. Once in gear it pulls really hard, more than what the mph seems to indicate, the car can't be powershifted, or speedshifted, and I'm sure this is hurting its perfromance.
 
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