Mopar "Street" heads

GO 4LO

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Re: Mopar \"Street\" heads

Hey, are you on the 3si board too? Just realized you were the Dynamic Racing guy. Don't know anything about the Mopar heads, but several reputable companies make aftermarket heads. BTR is coming out with an inexpensive (relatively speaking) Stage II head setup, if you're interested. HTH.
Chris
 

LTHL VPR

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Re: Mopar \"Street\" heads

We have flow tested stock intakes, and extrude honed and modified intakes both on and off heads. Our testing results indicate that the MOPAR heads take more advantage of the flow of the intake.
 

LTHL VPR

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Re: Mopar \"Street\" heads

1BADGTS-
You bring up some excellent points. I don't think I said the MOPAR heads necessarily made more horesepower, I just said, once modified, we have found that we can get more flow from them than stock modified heads. Like others, we have found that the limitation of the system is the intake. Overall, for the reasons above, we still prefer to use the MOPAR heads. They are nice aftermarket pieces.
Thanks!
-Wayne
 

Tom Welch

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Re: Mopar \"Street\" heads

Matt,

No need for wasted dollars on overkill heads that you can't get the benefit from because of your intake manifold/exhaust manifold.

A good ported stock head with big valves will give you plenty of additional power while leaving a few thousand dollars in your wallet!

Tom
Http://btrviper.com
 

Ron

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Re: Mopar \"Street\" heads

<FONT face="Comic Sans MS">If the limitation is the intake manifold, why doesn't someone design and cast up a hi perf version. Though expensive, it would have to be cheaper than the 10 throttle body setup....</FONT f>
 

LTHL VPR

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Re: Mopar \"Street\" heads

GREAT QUESTION!
We, APEX Motorsports, use the MOPAR heads on our LETHAL 600 and, soon the be announced, LETHAL 650 packages. The MOPAR heads are superior to the stock heads and we choose them for the following reasons:
1) They provide better cooling over the stock heads
2) The will flow more cfm than stock heads after both are modified
3) Overall better design.
4) They come with better guides and seats
5) Requires less down time when removing/installing heads
6) Ensures our customers get new heads every time. No swap out/core charges where we might be sending you someone else's heads with no history on them.

We have built several sets of heads so far, and we feel we found the right formula for getting excellent flow and making great power as a bolt on.

You can reach me privately with any questions at 408.562.1000.
Thank you.
-Wayne (LTHL VPR)
 

MES

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Re: Mopar \"Street\" heads

Can someone explain how you "drop a valve" in graphic detail? What exactly happens to the retainers/rockers or what ever causes this? I don't know much about heads but why would this be a big concern when replacing the stock heads?
 

Tom Welch

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Re: Mopar \"Street\" heads

MES,

The term "dropping a valve" means that the valve has came loose from the locks and retainer and has fallen into the combustion chamber.

This is most often caused by incorrect matching of the valve retainer and locks, although sometimes it can be caused by valve float which happens at an rpm which exceeds the valvesprings ability to close the valve quick enough.

You ask why does this happen on stock heads? As you will read a little farther down, because the head modification was done incorrectly. No other reason! Unfortunately there are very few aftermarket components for upgrading the valvetrain on viper heads. The Mopar Performance Catalogue only list valves and if you call DC they do not offer the rest of the components. Failures have occured because of mixmatches of components ie, the wrong retainer and lock for the valve stem, substitution of parts that are not a perfect fit but may have worked in another application, and adjusting the head through machining to accept parts that were not originally designed for our application. We have worked with a manufacturer of valves and components to create a CORRECT combination of valve, spring, and retainer from scratch. No one else has this. There is one other company that makes a combination for the viper head, and I believe that they are the only other ones. They could not meet our pricing demands.

Another term, "dropping a valve seat" means that the valve job was done based upon the valve dimension, not the seat dimension(a common misconception), which results in the valve hammering the seat until it comes loose. Remember that the viper uses a cylinder head manufactured from cast aluminum, while the valve seats are made of steel. they are bonded together, but seeing that they are different materials and subject to expansion at different temperatures, the undue stress of a poorly executed valve job could possibly result in the seat being beat out of the head, especially with high cylinder temperatures caused by raised compression, etc.

Feel secure in knowing that in all of the years that I have been racing drag cars, some of which exceeded 1000 rwhp and ran 7 second elapsed times, NEVER, and I repeat NEVER, have we had a head drop a valve or have we had a valve seat fail! Proper clyinder head modification techniques will insure the longevity of valvetrain upgrades on ANY cylinder head.

Many folks are using larger valves on their stock viper heads with no valve problems at all. Look into the few and far between failures and you will find the root cause to be a poorly executed cylinder head modification.

Don't be confused by things like Copper-burilium valve seats and other fancy terms for unnecessary products. Copper seats and stainless steel valves do not make a great combination especially for STREET/RACE use. In an all out race application(I have used titainium intake valves as large as 2.45")a titainium valve works well with a copper-burilium seat, although longevity becomes a concern.............which is expected from a high power producing racing engine that requires frequent maintenance. Not to mention that titainium valves are very, very expensive!

I hope that this answers your questions and maybe answers a few more that you might have. Shop around and gather information. Information is knowledge. Knowledge can help you find the best value for your viper without wasting money on unnecessary add ons that don't help your car and MAY even hinder its long term performance.

This of course, is my opinion based upon decades of my personal experience with racing engines. Other opinions are sure to surface.

Tom
Http://btrviper.com
 

MES

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Re: Mopar \"Street\" heads

Thanks, Tom for the reply. Are you going to Moroso this Sunday? I will be there if it don't get canceled by Gabrielle
pissed.gif
I'm looking at options for replacing/upgrading my heads.
 

Mike Adams

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Re: Mopar \"Street\" heads

Mopar heads are definetely better. Their are some secrets needed to make them work properly. I have found an extra 10 to 20 hp over stock heads. They require an good air intake like hennessy's and a proper cam shaft. With better cooling you can run higher compression.
 

LTHL VPR

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Re: Mopar \"Street\" heads

We found similar results to what Mike has realized. You can massage the exhaust side on the Mopar heads to flow better than stock modified heads, and the improved cooling allows a slightly higher compression bump.
 

HouseofSpeed

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Re: Mopar \"Street\" heads

Often times what occurs is the following....Squirrel A has his heads ported and gets *** CFM at *** LIFT....but the potential of that head/runner/port is not realized because of 1) bore size (my APEX compadres should know about this with SBF stuff...most aftermarket Windsor heads do not like a 4" bore, they perform better on a 4.030 bore) 2)the cam is just wrong, and for those that don't know...lift is not where the power secrets are at..its all in the event timing...look how much power a restricted class racer can make on a .480 lift rule (this applies to circle track and drag racing) 3) the intake is a complete piece of crap, much like the stock Viper intake.

Now within this very broad discussion, other things can easily be overlooked....ie, do I really want a head that flows like a DRCE/Big Chief on my Viper......the answer would be NO. Flow numbers are for those that are not very engine savvy....one has to be concerned with valve sizing (whether a big replacement valve will actually cause "shrouding"), runner cross-section (both manifold and head), what the turns within the port do to airflow....and most importantly, if my head moves a ton of air, can the engine use it.

As an FYI, Buddy Bar casts all of the V-10 heads....stock, MOPAR perf, and GTSR....and I will say that we have not seen any HP difference from a ported stocker to a ported MOPAR. Seems like a waste of cash and all of the conjecture on more "meat" in the runners and more cooling capacity seems like smoke and mirrors to justify the purchase. All of the castings have EXTREME variations in terms of wall thickness and any extra "coolant capacity" from revised water passages seems to be a stretch....if I add a cup full of water to the system, its kind of like ******* in the ocean and waiting for it to rise.
 

HouseofSpeed

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Re: Mopar \"Street\" heads

1bad....you are on the right track....conventional cam theory doesn't bode very well for the V10. Take advantage of the strong points of the head...look to the exhaust side in your quest. Wish I could give up all my info...but I had to experiment too much to give it up for free.
 

wmw1

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Re: Mopar \"Street\" heads

A few questions on this subject of cylinder heads.The spec-CC's on all three cylinder heads,before and after: cnc or manual porting.Also the spec-CC's on the amount of coolant
the three differant heads hold.
Stock,Mopar Performance,and GTSR Racer heads.

There is also areas that are not spoken of as to increase fuel volume and fuel delivery with the stock or mopar performance computer.How are you correctly controlling injector pulse-width & ign tables that are preset from the factory.Which won't allow you to release the extra HP&TQ from your add on parts.There maybe some products which will offset the factory settings untill the computer sees the change,then it will in return ajust the offset settings back to the factory pre-set settings.So you are only fooling the computer for a short time.Real changes to the factory sealed computer,being stock or mopar performance unit would mean that you would have to reconfigure the E-prom or EE-prom.In this case you are changing the factory ajustments and will cause a problem with your Warranty & Emissions Laws.Wm
 

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