Interesting vid about rocker arm ratios and more power

VIPR PWR

VIPR PWR

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Very interesting info I didnt know much about !
Made me wonder what changing the ratio on the 10's would do .

What is the stock ratio of the 10's rocker arms ?
What is the max cam lift on a stock engine ?
Are the intake and exhaust ratios different on the stock engine ?

Going foward and asking @rottenronnie and @Kiwi SRT10 ... What are the cam lift and ratio specs on you NA engines using the Striker heads .
Would changing the ratios be beneficial onmeither stock or Striker head engines ?
What would the estimated power gain be , doing a rocker ratio change ?

He states in the vid.. that the exhaust ratio change to a lower ratio will help with scavenging !



 
The Dodge Viper SRT10 typically uses a 1.7 rocker arm ratio. This ratio is commonly found in the Gen 3 and later versions of the Viper engine. Earlier models (Gen 1 and 2) may have had different ratios, such as 1.5 or 1.6, according to
 
divco13 said:
The Dodge Viper SRT10 typically uses a 1.7 rocker arm ratio. This ratio is commonly found in the Gen 3 and later versions of the Viper engine. Earlier models (Gen 1 and 2) may have had different ratios, such as 1.5 or 1.6, according to
Click to expand...
Are they the same Ratios for intake and exhaust ?
 
Based on the information available, the Dodge Viper V10 engine typically uses rocker arms with the same ratio for both intake and exhaust valves, such as 1.7.
However, it's worth noting:
  • Production vs. Aftermarket: While the production Viper engine might use a standard ratio like 1.6, aftermarket performance rocker arms for the Viper V10 often have a 1.7 ratio.
  • Performance Enhancement: Using higher ratio rocker arms, like the 1.7 ratio, can improve engine breathing and overall performance.
  • Specific Instructions: Always refer to the specific instructions provided with any rocker arm kit, like the Jesel instructions, to ensure proper installation and confirm the recommended ratio.
  • Checking for Clearance: When using aftermarket rockers, it's crucial to check for head and valve cover clearance, and proper lifter preload.
In summary, the most common rocker arm ratio for the Viper V10, especially for aftermarket performance applications, appears to be 1.7, and this ratio is generally the same for both the intake and exhaust sides.
 
VIPR PWR said:
Are they the same Ratios for intake and exhaust ?
Click to expand...
Based on the information available, the Dodge Viper V10 engine typically uses rocker arms with the same ratio for both intake and exhaust valves, such as 1.7.
However, it's worth noting:
  • Production vs. Aftermarket: While the production Viper engine might use a standard ratio like 1.6, aftermarket performance rocker arms for the Viper V10 often have a 1.7 ratio.
  • Performance Enhancement: Using higher ratio rocker arms, like the 1.7 ratio, can improve engine breathing and overall performance.
  • Specific Instructions: Always refer to the specific instructions provided with any rocker arm kit, like the Jesel instructions, to ensure proper installation and confirm the recommended ratio.
  • Checking for Clearance: When using aftermarket rockers, it's crucial to check for head and valve cover clearance, and proper lifter preload.
In summary, the most common rocker arm ratio for the Viper V10, especially for aftermarket performance applications, appears to be 1.7, and this ratio is generally the same for both the intake and exhaust sides.
 
VIPR PWR said:
So your using 1.7 ratio rockers on both intake and exhaust with the striker heads ?
Valve cover spacers using the strikers was due to what ?
Click to expand...
The striker heads are a totally different design. Valve angle, spark plug angle, straightened out the runners.
I bought them because they are sooooo rare. I don't care if you can do the same power with modified gen4 heads.
The Jesel roller box came with the heads.

Striker Viper Cylinder Heads Striker Viper Cylinder Heads [] : Southeast Performance R/T | Because Knowledge Breeds Winning Power

The J.M. Striker Head is the first and only head of its kind. J.M. used over 15 years of racing head experience to develop the Viper Striker Head. J.M. realized the Viper is a superior car that needed a superior cylinder head. The Striker head will meet and exceed an impressive amount of abuse...
www.southeastrt.net www.southeastrt.net
 
Hello
Yes, I co-wrote this article with Jeff Morys (Father Striker) and it was posted under Ronnies HP Heads. It also showed up on the www.southeastrt site not long after. The information within it is accurate and is unchanged which is the important part.

As the Striker-headed Gen III Vipers were beating up on the then new Gen IV Vipers in road-racing circuits, Jeff had to cease and desist production of the Strikers or lose his job with Chrysler.

Unlike the Strikers, the Gen IV isn't a direct bolt on for the Gen III as you know but is a great flowing head, particularly in the all-important mid-lift region where a valve spends most of its time. But, as you may be aware flow comparisons and how it correlates to power isn't the whole story. *See the above paragraph* ;)

The Gen IV head was a factory max effort within the constraints of mass production and there isn't much room for improvement. The Street Striker and Striker-R have additional room to port for an intended application adding a meatier deck, plug location, cooling, materials, etc.
They were also designed to increase torque over a VERY WIDE r.p.m.range which is part of the reason for the "Street" designation. The torque/horsepower range can be manipulated with camshaft choice. Particularly one with a narrow L.S.A.

Dom was just getting started on his 7-second project with Unmolested Striker-Rs, so their performance potential speaks volumes.

I'm not sure what kind of catch-can you have. I did the R&D for the company that manufactured mine and found I had to restrict the main vacuum line. As Viper engines don't use a pcv valve, ALL of the engine vacuum pulls pretty hard through your main catch can line. So you may want to look at that.

Dynos are a tuning tool and in North America SAE J1349 is a correction factor used so measured performance would be the same at sea-level or at the top of a mountain.

Altitude is a big factor in real-world performance. My own truck loses (on average) 80 horsepower here at home compared with a sea-level track.

Your dyno pull will provide a Baseline.
A stock Gen III (manual trans) will often be 425 wheel on a chassis dyno. You can expect to have picked up around 150 wheel or more.

If your numbers aren't as expected, don't sweat it. Just dial in your valve lash and go have some fun.
 
Last edited:
rottenronnie said:
Hello
Yes, I co-wrote this article with Jeff Morys (Father Striker) and it was posted under Ronnies HP Heads. It also showed up on the www.southeastrt site not long after. The information within it is accurate and is unchanged which is the important part.

As the Striker-headed Gen III Vipers were beating up on the then new Gen IV Vipers in road-racing circuits, Jeff had to cease and desist production of the Strikers or lose his job with Chrysler.

Unlike the Strikers, the Gen IV isn't a direct bolt on for the Gen III as you know but is a great flowing head, particularly in the all-important mid-lift region where a valve spends most of its time. But, as you may be aware flow comparisons and how it correlates to power isn't the whole story. *See the above paragraph* ;)

The Gen IV head was a factory max effort within the constraints of mass production and there isn't much room for improvement. The Street Striker and Striker-R have additional room to port for an intended application adding a meatier deck, plug location, cooling, materials, etc.
They were also designed to increase torque over a VERY WIDE r.p.m.range which is part of the reason for the "Street" designation. The torque/horsepower range can be manipulated with camshaft choice. Particularly one with a narrow L.S.A.

Dom was just getting started on his 7-second project with Unmolested Striker-Rs, so their performance potential speaks volumes.

I'm not sure what kind of catch-can you have. I did the R&D for the company that manufactured mine and found I had to restrict the main vacuum line. As Viper engines don't use a pcv valve, ALL of the engine vacuum pulls pretty hard through your main catch can line. So you may want to look at that.

Dynos are a tuning tool and in North America SAE J1349 is a correction factor used so measured performance would be the same at sea-level or at the top of a mountain.

Altitude is a big factor in real-world performance. My own truck loses (on average) 80 horsepower here at home compared with a sea-level track.

Your dyno pull will provide a Baseline.
A stock Gen III (manual trans) will often be 425 wheel on a chassis dyno. You can expect to have picked up around 150 wheel or more.

If your numbers aren't as expected, don't sweat it. Just dial in your valve lash and go have some fun.
Click to expand...
Great knowledge again. Thanks Ronnie.
It seems strange that for 5000 miles the catch can has not been an issue then suddenly a week ago it is hoovering out the rocker covers. Wicked amount of suction. Seems a lot more than last engine. Is that possible? Maybe it is saying I am sealed up and ready to go?
Does anyone know how many Striker Heads were made?
Mine are stamped SS30158

1ecddf7b-9332-4401-834f-925a65f00a32.jpg
 
Kiwi SRT10 said:
Great knowledge again. Thanks Ronnie.
It seems strange that for 5000 miles the catch can has not been an issue then suddenly a week ago it is hoovering out the rocker covers. Wicked amount of suction. Seems a lot more than last engine. Is that possible? Maybe it is saying I am sealed up and ready to go?
Does anyone know how many Striker Heads were made?
Mine are stamped SS30158

View attachment 68988
Click to expand...
Around 70 sets of Strikers were sold worldwide for the Gen III engine.
Yes it is very likely the new engine produces more vacuum above 1000 rpm.
For the catch can restrictor, it was a visit to Home Depot. In their irrigation parts area I found a 1/2" brass barbed plug that was flat (sealed) on one end. A 3/16" hole was drilled into that end and it was forced into the main 1/2" vacuum hose.
Keep your oil level up in the pan until this is resolved as it will lower the level very fast! Particularly if it is quite black from excessive combustion gas.

W.O.T. is critical (better sooner than later) to properly load and lap the rings to the cylinder walls. Then get the oil changed a.s.a.p.
If you wait and baby that new engine you will NOT be doing it any favours as the light honing pattern used today gets glazed and your engine won't make the anticipated power levels.
I had my new engine build bouncing off the Rev limiter with approx. 100 miles on it.
If you care.
I did/do.
 
Last edited:
VIPR PWR said:
Are they the same Ratios for intake and exhaust ?
Click to expand...
Yes 1.7 on both Intake and Exhaust.
Taller valve covers (spacers) were required because of the shaft-mounted Jesel/T&D adjustable roller valve train installed. This is part of a COMPLETE valvetrain overall with new heads.

In my opinion, there are better/simpler ways to boost power on a near stock Gen III, like a ported throttle-body.

IF you could find say a 1.8 stamped steel rocker, your valve is now operating in a new area on the valve guide with increased side-loading stress. Speaking of stress, you are also asking a valve spring to compress more than it is used to and particularly on an engine with several miles, NOT a good idea.

On a race engine, fine tuning with different rocker ratios is great and has worked for years.

As for less exhaust lift=better scavenging it isn't quite that cut and dried. If you listen again in the video, it is partially explained but is confusing the way it was delivered, I think.
Generally a smaller opening creates more velocity. In an engine with restricted exhaust ports or headers a camshaft favoring more exhaust lift and or duration can help create longer and (hopefully) more thorough scavenging.

That guy has a lot of very good information based on what he has seen or experienced. Like we all try to pass along in life, maybe. ;)




Cheers!
 
Last edited:
rottenronnie said:
Yes 1.7 on both Intake and Exhaust.
Taller valve covers (spacers) were required because of the shaft-mounted Jesel/T&D adjustable roller valve train installed. This is part of a COMPLETE valvetrain overall with new heads.

In my opinion, there are better/simpler ways to boost power on a near stock Gen III, like a ported throttle-body.

IF you could find say a 1.8 stamped steel rocker, your valve is now operating in a new area on the valve guide with increased side-loading stress. Speaking of stress, you are also asking a valve spring to compress more than it is used to and particularly on an engine with several miles, NOT a good idea.

On a race engine, fine tuning with different rocker ratios is great and has worked for years.

As for less exhaust lift=better scavenging it isn't quite that cut and dried. If you listen again in the video, it is partially explained but is confusing the way it was delivered, I think.
Generally a smaller opening creates more velocity. In an engine with restricted exhaust ports or headers a camshaft favoring more exhaust lift and or duration can help create longer and (hopefully) more thorough scavenging.

That guy has a lot of very good information based on what he has seen or experienced. Like we all try to pass along in life, maybe. ;)




Cheers!
Click to expand...
Thanks Ronnie ,, that helps make more sense to me ..
 
Have to go and get some degreaser tomorrow. Made a restrictor with a 3/16" 4mm hole.
Ran engine for awhile with nose uphill until oil smoke cleared. It settled nicely. Went for a test drive. Went well. Got back in the driveway cabin started filling with smoke. The dipstick wasn't in properly. Spat oil all over engine bay. I can't be 100% sure if was in properly or whether I need to increase the orifice. Went for another test drive, seems OK. Will keep an eye on that. Another mess to clean up.
 
Kiwi SRT10 said:
Have to go and get some degreaser tomorrow. Made a restrictor with a 3/16" 4mm hole.
Ran engine for awhile with nose uphill until oil smoke cleared. It settled nicely. Went for a test drive. Went well. Got back in the driveway cabin started filling with smoke. The dipstick wasn't in properly. Spat oil all over engine bay. I can't be 100% sure if was in properly or whether I need to increase the orifice. Went for another test drive, seems OK. Will keep an eye on that. Another mess to clean up.
Click to expand...
Got pics how the catch can is set / hooked up ?
Could the pressure be causing the dipstick to push out ?
Maybe removing and going to the factory PCV venting set up will improve the pressures ?
Isnt there a baffle in the valve cover from the factory ?
Ive never seen/had oil blowout of the dipstick and would assume it would take excessive pressure to do that .. dangerous and cause seals and gaskets to leak and blow out !
 
Gooday.
The tab on the dipstick tube has to be cut off and relocated (brazed) as the valve cover bolt hole it used before is now 1" higher than it was due to the spacers.
Maybe that wasn't done (??)
 
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