Comp vs. Crane vs. Patriot vs. Precision vs. Rev
11-01-2004, 02:14 PM
#1
Comp vs. Crane vs. Patriot vs. Precision vs. Rev Comp dual valve spring kit-Roughly $560, .650" lift
Crane dual valve spring kit-Roughly $390, .650" lift
Patriot dual valve spring kit-$290, .650" lift
Precision dual valve spring kit-Roughly $290, .660" lift
Rev dual valve spring kit-Roughly $335 without valve stem seals, .650" lift
All have about the same rated lift and all have the same parts in the kit, but what makes them differ from one another besides price? Big difference between the Crank, Patriot, Precision, and Rev from Comp's kit. Comp's kit is the most expensive, but is it really worth the extra money? They all have the same parts in the kit and rated for the same lift, I dont see why there is difference in prices especially with the Comp. Im looking for a valvetrain kit for the T-Rex cam. What do you recommend? Thanks.
Crane dual valve spring kit-Roughly $390, .650" lift
Patriot dual valve spring kit-$290, .650" lift
Precision dual valve spring kit-Roughly $290, .660" lift
Rev dual valve spring kit-Roughly $335 without valve stem seals, .650" lift
All have about the same rated lift and all have the same parts in the kit, but what makes them differ from one another besides price? Big difference between the Crank, Patriot, Precision, and Rev from Comp's kit. Comp's kit is the most expensive, but is it really worth the extra money? They all have the same parts in the kit and rated for the same lift, I dont see why there is difference in prices especially with the Comp. Im looking for a valvetrain kit for the T-Rex cam. What do you recommend? Thanks.
11-01-2004, 03:19 PM
#3
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Don't forget Manley, they have a dual drop in from their Nextek line. After owning both sets of Cranes( old and new with stripes)I would not recomend them. Also the Cranes have the lowest open and closed pressures base on a 1.8 installed height.
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11-01-2004, 07:06 PM
#8
Well from what I know, Comp and Crane are well know valvetrain manufacturers that have been around a while. Rev, Patriot, and Precision Ive only heard of because of this site. Rev I believe was introduced first, then Patriot, and then lastly the Precision. The Patriots and Pecisions are the same price, yet the Precisions have .660" lift which is .010" more than the rest. Does anyone know why the Comps are almost double the Patriots and Precisions?
Vortech: Why dont you recommend the Cranes?
MARKSZ71: Why would you choose the Precisions over the Patriots? Theyre about the same price, yet the Precisions were just introduced here not too long ago?
Vortech: Why dont you recommend the Cranes?
MARKSZ71: Why would you choose the Precisions over the Patriots? Theyre about the same price, yet the Precisions were just introduced here not too long ago?
11-02-2004, 08:06 AM
#10
Patriot .650" Gold Dual Spring Kit comes with The Orginal Patriot Gold Dual springs, ti retainers, super 7 locks, spring bases, and viton rubber seals.
All of this for only $279.50 !!
All of this for only $279.50 !!
11-02-2004, 09:21 AM
#12
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Exactly! The Cranes have the lowest open and closed pressures. Depending on your cam, heads, valves u will need to shim so they work. With the other brands u can just drop them in as they are 140@1.8 while the cranes are only 112@1.8
11-02-2004, 12:31 PM
#13
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Originally Posted by Vortech
Exactly! The Cranes have the lowest open and closed pressures. Depending on your cam, heads, valves u will need to shim so they work. With the other brands u can just drop them in as they are 140@1.8 while the cranes are only 112@1.8
Here is the response I got from Crane when I asked him about shimming:
Originally Posted by Mark Campbell from Crane
Sorry for the delayed response, but I was out of the state for a couple of days. There has been a good deal of misinformation about what shimming will and will not do. Shimming should not have a significant affect on valve spring life. It also doe not affect the harmonics of the spring but can affect the harmonic stimulation of the pushrod. It is necessary to provide adequate seat pressure to keep the valves from bouncing as they return to the seat. Fortunately, the LS1 valve train is relatively light and the large stock rocker ratio (1.7) multipies the seat pressure to help prevent bouncing of the lifter on the lobe. Our spring sets up at 112# at 1.800" installed height. We have purposely designed the spring with this seat pressure to allow shimming to the needs of the cam profile. We have kept the valve spring rate on the moderate side to keep the valve spring open loads from causing too much pushrod deflection at max lift. Too much open pressure will cause the pushrod to bend like a pole vaulters pole and cause an undesired "throwing of the valve" which means you have lost control of the valve train. Too much pressure and too high of a spring rate can cause just as many if not more problems than too light of a rate! (There are harmonic issues which are quite complex that relate to spring rate, lift rate of the lobe and rocker arm ratio that would take a text book to explain). If the seat pressure and spring rate are too high to start with, it's impossible to remove pressure!!. We also like the harmonics of this spring design over a wide range of applications. We feel our harmonics provide the best operation over the widest operating range of any spring on the market, and we have tested them all. I would recommend 120-125# of seat pressure for your application. A .030" shim should be the proper shim to place under the spring to achieve this seat pressure. This equates to a 1.765-1.770" installed height. With that seat pressure you should have no problems with valve train separation throughout your entire operating range (i.e. you will run into valve float problems from the inherent design characteristics of the lobe before you reach a critical harmonic in the spring!). Indiscriminately throwing valve spring shims under a spring is a sure way to disaster. We recommend measuring the istalled height of each valve spring and shimming as necessary to achieve the desired seat pressure. The seat pressure is the most important issue here and we have tried todesign a spring that provides maximum flexibility for maximum performance. We think we have succeeded. If you have any othe questions or issues, please feel free to contact me.
11-02-2004, 01:03 PM
#14
What are the Super 7 locks?
GUNNAR@PATRIOT: When you say orginal Patriot Gold Dual Springs, is there another drop in dual spring that Patriot offers? Why did Texas Speed and Performance stop carrying this kit? The only sponsor that Ive run into so far that carries the Patriot kit is Speed Inc. and they sell the kit for $290. Where can I get it for $279.50 as you listed?
Do the Cranes come with shims? How will I know what shim to use?
GUNNAR@PATRIOT: When you say orginal Patriot Gold Dual Springs, is there another drop in dual spring that Patriot offers? Why did Texas Speed and Performance stop carrying this kit? The only sponsor that Ive run into so far that carries the Patriot kit is Speed Inc. and they sell the kit for $290. Where can I get it for $279.50 as you listed?
Do the Cranes come with shims? How will I know what shim to use?
11-02-2004, 01:07 PM
#15
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The Cranes don't come with shims. That's the whole thing-If i were to do it again I wouldn't use the Cranes. To use the cranes properly u have to get a crane installed height micrometer and a spring pressure tester to see what pressure the cranes will be at what installed height. All the other brands offer 140@1.8-u have to shim the Cranes to get that.
11-02-2004, 01:12 PM
#16
Super 7 was a lock design of the late Randy Dorton. It is the only style of lock used in Nextel/Busch/Truck series engines due to its inherent design of not allowing the valve to drop if a spring breaks. Only difference since the cup teams run ti-valves with tips, their locks are taller and surround the tip to guard against it coming off.
Chris
Chris
11-02-2004, 01:30 PM
#17
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I have heard of 1 or 2 super7 failures but never on the stock ones. I know that the Comp stuff is dead reliable but the price kills 'em. Also the patriots are doing well out in the field but the PRC looks nicer on fitment of all the parts. I think the Cranes got hurt in the pressure department because when you shim the spring what ever thickness of shim you use takes that much away from how much lift the spring can handle safely. Hope this is helful info.
11-02-2004, 02:00 PM
#19
Is Patriot the only company that offers the Super 7 locks? How come none of the other dual kits mentioned in this thread dont offer these locks? When you say locks, are you referring to the "keepers"?
Bo White: Why do you say the Precision kit looks better than the Patriot? Have you used/seen both kits in person? On most things, looks dont matter, but in this case, does looks make a difference? Reason why I brought that up is because you said the Precision kit looks nicer.
Bo White: Why do you say the Precision kit looks better than the Patriot? Have you used/seen both kits in person? On most things, looks dont matter, but in this case, does looks make a difference? Reason why I brought that up is because you said the Precision kit looks nicer.