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RCP Phx Samba Member
Joined: November 20, 2021 Posts: 496 Location: Phoenix,AZ
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Posted: Sat Nov 20, 2021 1:37 pm Post subject: Existing cam wanting to add 1.3 ratio rockers |
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I have a 1955cc motor that I built a few years back. I want to add some 1.3 roller rockers to my existing cam. The cam is a bugpack 4062 (.284*/.415") on 044 heads. My question is whether that will work and if it would be a good idea. |
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QRP Samba Member
Joined: April 27, 2008 Posts: 1712 Location: NORTH HOLLYWOOD,CA
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Posted: Sat Nov 20, 2021 2:10 pm Post subject: Re: Existing cam wanting to add 1.3 ratio rockers |
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That cam with standard 1.1:1 rockers is already giving you almost. 460 lift
With 1.3:1 you'll be at .540
I wouldn't do it, but thats just me. |
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clonebug Samba Member
Joined: January 29, 2005 Posts: 4027 Location: NW Washington
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Posted: Sat Nov 20, 2021 2:39 pm Post subject: Re: Existing cam wanting to add 1.3 ratio rockers |
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Let me give you my experience on changing rockers......in the quest to get "More" power......
W-100 cam with .383" at the cam. I figured maybe some `1.25 rockers for around .500" lift would improve the hp. They are recommended to run 1.1 or 1.25 only.
Asked a few questions and those that replied said it would be doable..
Bought a set of 1.25 rockers....
Set them up and found they were measuring out at 1.37-1.38....
Call the Ebay supplier and he sent another set no charge....said he'd measure to make sure they were 1.25...they were exactly the same.
Decided to go for it anyways even though it wasn't correct for the cam.....
Had them narrowed to fit better and allow shims to adjust side play to minimal for optimum lift and lowest noise. I also had the lash caps machined for a tight fit to the valves since they wouldn't work as bought.
Bought a set of Cromoly .035" pushrods so I could cut them to length.
By now I had almost $300 .00 into them.....I now had narrowed rockers, pushrods and shims galore.
I spent a lot of time on geometry and then had my neighbor cut them to length on his mill. It worked great and I installed the ends. Added CB 650 outer springs for the extra lift. Milled off about .070" from the rocker blocks on the head for better geometry.
When all was said and done I had 1.38:1 ratio rockers on my W-100 cam putting out .526" lift.
All in all it was about a $500.00 upgrade not including the time it took to set the geometry.
That is the short version..........
HP gains???? Couldn't really tell on the butt dyno.
I did manage to blow my spider gears out on the trans.
Was it worth it??? Still testing.
I put 3660 miles on that particular valve train and when pulled apart the cam and lifters were in perfect condition..They have a combined 46,000 miles on them. I could have kept that setup but I swapped to a FK-42 which is compatible with 1.4 rockers.
That now has 4100 plus miles on it with no issues and quiet running. It has almost exactly the same lift and a little more duration but it really hasn't given a noticeable hp gain either.
Although with the California trip last summer and the trans issue 1100 miles from home I haven't really given it the testing it deserves.
It is a great driver though.......
A lot of the "Upgrades" I have done have had a very low hp/$$$ return on my investment.
The cheapest hp was the turbo addition....but over time that isn't really cheap because you keep wanting more and will sell your left testicle to get more boost.
Now if I could just be happy with the 226 hp I have........ _________________
vwracerdave wrote: |
Take a good long look in the mirror and report back on what you see. |
Paul.H wrote: |
That one line on that chart is probably better info than you can get from this place in a month |
My Megasquirt Fuel Injection Turbo Buggy Build
Water/Alcohol Injection
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Upgraded to MS3Pro-Evo
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http://www.shoptalkforums.com/viewtopic.php?f=3&t=127936 |
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RCP Phx Samba Member
Joined: November 20, 2021 Posts: 496 Location: Phoenix,AZ
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Posted: Sat Nov 20, 2021 2:45 pm Post subject: Re: Existing cam wanting to add 1.3 ratio rockers |
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I believe the cam is rated .415" w/ 1.1:1 rockers that means the change put me at .490" of lift. I'm not looking for more lift but I did purchase the Pauter roller rockers, I just am trying to find out if I can get away with it without splitting the case and changing cams? I'm already thinking about some beehive springs to replace the CB springs that are in there now. |
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NJ John Samba Member
Joined: September 21, 2007 Posts: 2224 Location: HdG, MD & NJ
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Posted: Sat Nov 20, 2021 4:03 pm Post subject: Re: Existing cam wanting to add 1.3 ratio rockers |
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Maybe your larger displacement combo is wanting more lift and will benefit from it. Your valvetrain is probably up to the task. I would try. _________________ 1973 standard, yellow, lowered, 3” narrowed front, 1600 blo-thru turbo w/single dell 15.4@86, so far
11.41 et buggy. Long gone
Let’s go O’s! Let’s go O’s!
https://www.youtube.com/@AirSpooledGarage |
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Alstrup Samba Member
Joined: July 12, 2007 Posts: 7219 Location: Videbaek Denmark
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Posted: Sat Nov 20, 2021 4:47 pm Post subject: Re: Existing cam wanting to add 1.3 ratio rockers |
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RCP Phx wrote: |
I believe the cam is rated .415" w/ 1.1:1 rockers that means the change put me at .490" of lift. I'm not looking for more lift but I did purchase the Pauter roller rockers, I just am trying to find out if I can get away with it without splitting the case and changing cams? I'm already thinking about some beehive springs to replace the CB springs that are in there now. |
That was the golden info. - The CB HD sgl springs will not handle the extra lift/rpm. You need more. Your advantage is that that cam is very soft on the ramps so you do not have to go crazy on spring pressure. Beehives are more than sufficient. Scat springs with Ti retainers would do the job too.
Whether your engine will pay for it depends 100% on its breathing capabilities and whether you have enough time area on the valves as is. If your CR is on the low to medium for the cam I wouldnt bother. If it is set up to about max CR for the cam and engine it is worth a shot.
Remember, if you do not have enough static compression you will loose too much dynamic compression in the opening a nd closing phase. That WILL result in a power loss below approx 2800 rpm. and a typical power gain from about 3500 & up. If your static CR is "right" you should not loose any power down low, but gain power from about 3200 rpm. But it is a good alround cam, so don´t rule it out just yet.
How much more power(?) If the engine can exploit the extra lift/flow you can expect up to about 7% gain plus another 300ish rpm on top. Also, the torque band would be extended with 250-300 rpm.
If the heads/engine can barely exploit the extra lift you can expect something like 3,5-4% _________________ https://www.thesamba.com/vw/forum/viewtopic.php?t=435993 |
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RCP Phx Samba Member
Joined: November 20, 2021 Posts: 496 Location: Phoenix,AZ
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Posted: Sat Nov 20, 2021 5:15 pm Post subject: Re: Existing cam wanting to add 1.3 ratio rockers |
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The motor was built about 8yrs ago and I don't recall the CR I set it up with(probably around 8.5-9). For what it's worth I am also running a single 48IDF. |
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Dan Ruddock Samba Member
Joined: October 25, 2012 Posts: 3594 Location: Sarasota, in my adopted state of Florida
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Posted: Sat Nov 20, 2021 5:19 pm Post subject: Re: Existing cam wanting to add 1.3 ratio rockers |
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RCP Phx wrote: |
For what it's worth I am also running a single 48IDF. |
Yikes , put your money and effort into running duals two barrels. My beehive springs will work well with the valve train combo but like I said, dual 48's will work but kinda big for your combo. |
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Lingwendil Samba Member
Joined: February 25, 2009 Posts: 3988 Location: Antioch, California, a block from the hood
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RCP Phx Samba Member
Joined: November 20, 2021 Posts: 496 Location: Phoenix,AZ
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Posted: Sat Nov 20, 2021 5:51 pm Post subject: Re: Existing cam wanting to add 1.3 ratio rockers |
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This motor probably only has maybe 500 miles on it and I just did a serpentine conversion on it. The motor is also a long rod CB H-beam @5.500" (82 stroke pistons) and I love roller rockers! |
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RCP Phx Samba Member
Joined: November 20, 2021 Posts: 496 Location: Phoenix,AZ
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Posted: Sat Nov 20, 2021 6:12 pm Post subject: Re: Existing cam wanting to add 1.3 ratio rockers |
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Here's what I'm working on ......
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Alstrup Samba Member
Joined: July 12, 2007 Posts: 7219 Location: Videbaek Denmark
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FreeBug Samba Member
Joined: March 12, 2012 Posts: 4278 Location: deepest, darkest Switzerland
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Posted: Sun Nov 21, 2021 4:06 am Post subject: Re: Existing cam wanting to add 1.3 ratio rockers |
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There is going to be a lot of discussion about how "correct" that combo is. Strap in. |
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oprn Samba Member
Joined: November 13, 2016 Posts: 12740 Location: Western Canada
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Posted: Sun Nov 21, 2021 6:07 am Post subject: Re: Existing cam wanting to add 1.3 ratio rockers |
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Look for a set of see through valve covers, those rockers are very pretty! Nice addition to a pretty engine but a shame if they are hidden. _________________ We had the stone age, the bronze age, the industrial age and now we are in the age of mass deception and mind control for corporate profit. (The mass media age) |
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RCP Phx Samba Member
Joined: November 20, 2021 Posts: 496 Location: Phoenix,AZ
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Posted: Sun Nov 21, 2021 6:17 am Post subject: Re: Existing cam wanting to add 1.3 ratio rockers |
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I haven't been on here in years but I am hoping for lots of input on this. If I have to split the case I will probably just build a new motor with a new super case. This one was shuffled/welded by Rimco.
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NJ John Samba Member
Joined: September 21, 2007 Posts: 2224 Location: HdG, MD & NJ
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Posted: Sun Nov 21, 2021 7:30 am Post subject: Re: Existing cam wanting to add 1.3 ratio rockers |
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Again, it seems like a well built engine, but with a small cam. Put, the rockers on! _________________ 1973 standard, yellow, lowered, 3” narrowed front, 1600 blo-thru turbo w/single dell 15.4@86, so far
11.41 et buggy. Long gone
Let’s go O’s! Let’s go O’s!
https://www.youtube.com/@AirSpooledGarage |
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RCP Phx Samba Member
Joined: November 20, 2021 Posts: 496 Location: Phoenix,AZ
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Posted: Sun Nov 21, 2021 5:58 pm Post subject: Re: Existing cam wanting to add 1.3 ratio rockers |
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I finally found the build file on this one. I've got all the specs except I show the cam ordered was a CB 2239 (.276*/.417"@1.1:1) but I don't show it being delivered but since that's very close to the 4062 I'm not surprised that I would order one. I also show 5.400" rods so I'll have to re-compute those numbers. |
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Paul.H Samba Member
Joined: April 03, 2015 Posts: 613 Location: England
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Posted: Sun Nov 21, 2021 6:39 pm Post subject: Re: Existing cam wanting to add 1.3 ratio rockers |
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The cams OK and you may be OK with the rockers but the intake you have is the worst thing ever made for a VW and even worse with a 48 carb |
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Danwvw Samba Member
Joined: July 31, 2012 Posts: 8892 Location: Oregon Coast
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Posted: Sun Nov 21, 2021 8:32 pm Post subject: Re: Existing cam wanting to add 1.3 ratio rockers |
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Probably could run the Webcam 118 with the single HD springs and some good aluminum racing pushrods with the 1.3:1 rockers, Probably the CB-Performance UltraLight lifters would play nicely here: A dune buggy or baja benefits from a single carb so figure out how to jet that 48 for it Probably (32mm, 34mm venturi's) for it and it'ted probably be good. _________________ 1960 Beetle And 1679cc DP W-100 & Dual Zeniths! |
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Brian_e Samba Member
Joined: July 28, 2009 Posts: 3293 Location: Rapid City, SD
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Posted: Sun Nov 21, 2021 8:54 pm Post subject: Re: Existing cam wanting to add 1.3 ratio rockers |
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Any idea what the heads are and what they flow? If they are done flowing at .450”, than the extra lift won’t help all that much, other than holding the valve open a bit longer. If the heads keep flowing up past .500”, then the extra lift will help add more area under the flow curve, and help pack more air into the cylinders.
Are dual carbs an option with that buggy body? I would be doing those long before ratio rockers.
Brian _________________ www.type-emotorsports.com |
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