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ManFromNapa Samba Member
Joined: March 08, 2012 Posts: 184 Location: United States
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Posted: Mon May 03, 2021 3:55 pm Post subject: Compression Ratio for a 2231 Cam |
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Hey people. I'm building a 1600 for a daily driver. Using a 2231 cam for better MPG. Not looking to be super fast.
According to the AirCooled.net site, they recommend staying below an 8.5:1 compression ratio. I know higher compression ratio improves HP & efficiency, but it also produces more heat. What CR would most guys recommend? I had one builder tell me to stay down around 8.1, another tell me to get as much as I can out of it.
Again, this is a daily driver. Looking for longer life, and reliability. _________________ North Bay Air Cooled - VW Club in Napa, CA
http://www.northbayaircooled.com/
Check out my band, Thru The Haze
http://www.thruthehazeband.com/ |
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FreeBug Samba Member
Joined: March 12, 2012 Posts: 4278 Location: deepest, darkest Switzerland
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Posted: Mon May 03, 2021 4:05 pm Post subject: Re: Compression Ratio for a 2231 Cam |
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Hi, you'll need to specify the fuel you intend to use. |
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ManFromNapa Samba Member
Joined: March 08, 2012 Posts: 184 Location: United States
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Posted: Mon May 03, 2021 4:13 pm Post subject: Re: Compression Ratio for a 2231 Cam |
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FreeBug wrote: |
Hi, you'll need to specify the fuel you intend to use. |
Regular 87 Octane. _________________ North Bay Air Cooled - VW Club in Napa, CA
http://www.northbayaircooled.com/
Check out my band, Thru The Haze
http://www.thruthehazeband.com/ |
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mark tucker Samba Member
Joined: April 08, 2009 Posts: 23937 Location: SHALIMAR ,FLORIDA
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Posted: Mon May 03, 2021 4:52 pm Post subject: Re: Compression Ratio for a 2231 Cam |
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what ever cr you choose try to keep the deck around .040"(1 mm) I wont build any thing low cr like that.but thats me. |
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Teeroy Samba Member
Joined: April 20, 2003 Posts: 3685 Location: Eastern WA
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Posted: Mon May 03, 2021 5:36 pm Post subject: Re: Compression Ratio for a 2231 Cam |
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John puts those recomendations on the site for a reason, thats where they are designed to work best. Unless you live at a very high elevation or are gonna run a high octane fuel, set it were he says the specific cam recommends _________________ Pres. Rivercity VW Club www.rcvwclub.org
Founder Derr Wheat Panzers (DWP)
ARR #3
www.autosportsnorthwest.org |
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bugguy1967 Samba Member
Joined: January 16, 2008 Posts: 4343 Location: Los Angeles, CA 90016
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Posted: Mon May 03, 2021 7:10 pm Post subject: Re: Compression Ratio for a 2231 Cam |
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Let's see the cam card! _________________ "A petrol engine can start readily, run smoothly and give every appearance of being in good order, without necessarily being in good tune." - Colin Campbell, "The Sportscar Engine" |
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jpaull Samba Member
Joined: February 22, 2005 Posts: 3466 Location: Paradise, Ca
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Posted: Mon May 03, 2021 7:33 pm Post subject: Re: Compression Ratio for a 2231 Cam |
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bugguy1967 wrote: |
Let's see the cam card! |
The first relevant question that will lead to a relevant answer💪💪 |
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[email protected] Samba Member
Joined: May 17, 2003 Posts: 4863 Location: Harmony, PA
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Posted: Mon May 03, 2021 7:36 pm Post subject: Re: Compression Ratio for a 2231 Cam |
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bugguy1967 wrote: |
Let's see the cam card! |
I’m going to say intake closes around 41 degrees ABDC..... |
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ManFromNapa Samba Member
Joined: March 08, 2012 Posts: 184 Location: United States
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Posted: Mon May 03, 2021 8:53 pm Post subject: Re: Compression Ratio for a 2231 Cam |
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bugguy1967 wrote: |
Let's see the cam card! |
I just ordered the cam today, so I don't have the card yet. Was hoping someone else might. I appreciate everyone's comments. _________________ North Bay Air Cooled - VW Club in Napa, CA
http://www.northbayaircooled.com/
Check out my band, Thru The Haze
http://www.thruthehazeband.com/ |
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ManFromNapa Samba Member
Joined: March 08, 2012 Posts: 184 Location: United States
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Posted: Mon May 03, 2021 8:59 pm Post subject: Re: Compression Ratio for a 2231 Cam |
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Teeroy wrote: |
John puts those recomendations on the site for a reason, thats where they are designed to work best. Unless you live at a very high elevation or are gonna run a high octane fuel, set it were he says the specific cam recommends |
John is great and has always given me good advice. To be clear, his site says
"Use a compression ratio no higher than 8.5:1", but to me that's not a recommendation to have 8.5:1. Just not to go higher. _________________ North Bay Air Cooled - VW Club in Napa, CA
http://www.northbayaircooled.com/
Check out my band, Thru The Haze
http://www.thruthehazeband.com/ |
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Alstrup Samba Member
Joined: July 12, 2007 Posts: 7217 Location: Videbaek Denmark
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vwracerdave Samba Member
Joined: November 11, 2004 Posts: 15308 Location: Deep in the 405
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Posted: Tue May 04, 2021 7:12 am Post subject: Re: Compression Ratio for a 2231 Cam |
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1600 daily driver on 87 pump gas. 7.7-8.0 with the stock carb. 7.9-8.2 with dual carbs. _________________ 2017 Street Comp Champion - Thunder Valley Raceway Park - Noble, OK
2010 Sportsman ET Champion - Mid-America Dragway - Arkansas City, KS
1997 Sportsman ET Champion - Thunder Valley Raceway Park - Noble ,OK |
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Ohio Tom Samba Member
Joined: February 09, 2006 Posts: 1660 Location: Marshallville Ohio
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Posted: Tue May 04, 2021 7:41 am Post subject: Re: Compression Ratio for a 2231 Cam |
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8,0 would be the highest I would recommend.
Stay in the 7's for stock and near stock stuff.
Higher will only increase the fuel octane requirements and add heat.
Both will kill a motor.
You want it to last, right?
BTW premium fuel is $.95 more expensive a gallon than regular. |
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ManFromNapa Samba Member
Joined: March 08, 2012 Posts: 184 Location: United States
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Posted: Tue May 04, 2021 2:48 pm Post subject: Re: Compression Ratio for a 2231 Cam |
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Ohio Tom wrote: |
BTW premium fuel is $.95 more expensive a gallon than regular. |
I agree.. but I'm building this for a friend who I know will use 87. I'll try to stick to around 8.0:1 _________________ North Bay Air Cooled - VW Club in Napa, CA
http://www.northbayaircooled.com/
Check out my band, Thru The Haze
http://www.thruthehazeband.com/ |
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