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offrdbus70
Samba Member
Joined: August 23, 2006
Posts: 512
Location: Pine Valley-SD
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 Posted: Wed Jan 23, 2019 3:18 pm Post subject: Is 10.1 too high? |
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Hi all,
Been awhile since I posted. Opinions here. Rebuilding last years Powder Puff drag Ghia winning engine from last year and getting ready for this season.
I asked the head builder to kiss the heads when doing his valve job but now I have 47cc.
With a .054 deck and 74x94 I am 10.1 compression.
Car is used for drag racing and going to local shows. Occasional drive to work.
Norris 407s cam
Ported 044 heads 42x37.5
Dual Dell 40's
What do you guys think? Can I run 10.1 or will I ping?
Thanks! |
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Alstrup
Samba Member
Joined: July 12, 2007
Posts: 7216
Location: Videbaek Denmark
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| Posted: Wed Jan 23, 2019 3:27 pm Post subject: Re: Is 10.1 too high? |
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Donīt see why not. Just use Chevron 93 or similar with it.
PS. Its a track engine, right? |
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offrdbus70
Samba Member
Joined: August 23, 2006
Posts: 512
Location: Pine Valley-SD
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| Posted: Wed Jan 23, 2019 3:29 pm Post subject: Re: Is 10.1 too high? |
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| It is....mostly. We can only get 91 here in California. |
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mcmscott
Samba Member
Joined: March 12, 2010
Posts: 4856
Location: sanger ca
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| Posted: Wed Jan 23, 2019 3:30 pm Post subject: Re: Is 10.1 too high? |
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10:1 with a 407 is high, I would use CB's 2250 and leave everything else alone.
_________________
There are no stupid questions, only stupid people,
68 Ghia
67 T-1
65 Notch
02 Mexican beetle
74 Thing
15 Long travel rail
07 Nomad
05 f-250 |
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DerrickfromNC1
Samba Member
Joined: October 24, 2008
Posts: 1302
Location: North Carolina
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| Posted: Wed Jan 23, 2019 3:32 pm Post subject: Re: Is 10.1 too high? |
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| Can you get E85 gas? |
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mcmscott
Samba Member
Joined: March 12, 2010
Posts: 4856
Location: sanger ca
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| Posted: Wed Jan 23, 2019 3:34 pm Post subject: Re: Is 10.1 too high? |
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| DerrickfromNC1 wrote: |
| Can you get E85 gas? |
Not with Dells, it will destroy the floats in very short time.
_________________
There are no stupid questions, only stupid people,
68 Ghia
67 T-1
65 Notch
02 Mexican beetle
74 Thing
15 Long travel rail
07 Nomad
05 f-250 |
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Alstrup
Samba Member
Joined: July 12, 2007
Posts: 7216
Location: Videbaek Denmark
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| Posted: Wed Jan 23, 2019 3:35 pm Post subject: Re: Is 10.1 too high? |
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OK. I know it has been a while, but last I was in the LA area 93 was still available. I thought it still was.
E85 would the trick, with a rejet. |
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offrdbus70
Samba Member
Joined: August 23, 2006
Posts: 512
Location: Pine Valley-SD
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| Posted: Wed Jan 23, 2019 3:44 pm Post subject: Re: Is 10.1 too high? |
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| .020 Head gaskets get me to 9:6. Hate to do it but? I should I suppose. |
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vwracerdave
Samba Member
Joined: November 11, 2004
Posts: 15308
Location: Deep in the 405
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| Posted: Wed Jan 23, 2019 4:20 pm Post subject: Re: Is 10.1 too high? |
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| offrdbus70 wrote: |
| It is....mostly. We can only get 91 here in California. |
Mix race gas with street gas. I mix 1 gal of 110 with 3 gal of 91.
_________________
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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richierich
Samba Member
Joined: December 23, 2004
Posts: 889
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| Posted: Wed Jan 23, 2019 5:07 pm Post subject: Re: Is 10.1 too high? |
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| I run 10.2:1 on my street car and use super unleaded - 99 octane stuff. No pinging. Dont know what you have available at the pump in the US though. |
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vwracerdave
Samba Member
Joined: November 11, 2004
Posts: 15308
Location: Deep in the 405
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| Posted: Wed Jan 23, 2019 5:23 pm Post subject: Re: Is 10.1 too high? |
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| richierich wrote: |
| I run 10.2:1 on my street car and use super unleaded - 99 octane stuff. No pinging. Dont know what you have available at the pump in the US though. |
The USA uses a different system to rate octane then the rest of the world does.
_________________
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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richierich
Samba Member
Joined: December 23, 2004
Posts: 889
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| Posted: Wed Jan 23, 2019 5:28 pm Post subject: Re: Is 10.1 too high? |
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| vwracerdave wrote: |
| richierich wrote: |
| I run 10.2:1 on my street car and use super unleaded - 99 octane stuff. No pinging. Dont know what you have available at the pump in the US though. |
The USA uses a different system to rate octane then the rest of the world does. |
Ah, I did not know that. So, a US 93PON is the same as our 98/100RON. And he cannot get 93PON in California. Ok. |
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King_vw61
Samba Member
Joined: February 03, 2018
Posts: 1383
Location: Southern California
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| Posted: Wed Jan 23, 2019 6:09 pm Post subject: Re: Is 10.1 too high? |
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| Under 11 to 1 and you should be ok on 91, if there is an issue retard timing a few degree. Then bump it up at the track. |
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mcmscott
Samba Member
Joined: March 12, 2010
Posts: 4856
Location: sanger ca
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| Posted: Wed Jan 23, 2019 7:11 pm Post subject: Re: Is 10.1 too high? |
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| ivkings4 wrote: |
| Under 11 to 1 and you should be ok on 91, if there is an issue retard timing a few degree. Then bump it up at the track. |
Not with a 407 cam, that thing would pump 250 psi cranking pressure. The 407 is like a w100, very tame.
_________________
There are no stupid questions, only stupid people,
68 Ghia
67 T-1
65 Notch
02 Mexican beetle
74 Thing
15 Long travel rail
07 Nomad
05 f-250 |
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King_vw61
Samba Member
Joined: February 03, 2018
Posts: 1383
Location: Southern California
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| Posted: Wed Jan 23, 2019 7:16 pm Post subject: Re: Is 10.1 too high? |
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| mcmscott wrote: |
| ivkings4 wrote: |
| Under 11 to 1 and you should be ok on 91, if there is an issue retard timing a few degree. Then bump it up at the track. |
Not with a 407 cam, that thing would pump 250 psi cranking pressure. The 407 is like a w100, very tame. |
So please tell me that with a large cam (fk89/91) under 11:1 is workable?? If not I will be starting a gofundme page to cover my fuel cost,, |
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mcmscott
Samba Member
Joined: March 12, 2010
Posts: 4856
Location: sanger ca
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| Posted: Wed Jan 23, 2019 7:24 pm Post subject: Re: Is 10.1 too high? |
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| ivkings4 wrote: |
| mcmscott wrote: |
| ivkings4 wrote: |
| Under 11 to 1 and you should be ok on 91, if there is an issue retard timing a few degree. Then bump it up at the track. |
Not with a 407 cam, that thing would pump 250 psi cranking pressure. The 407 is like a w100, very tame. |
So please tell me that with a large cam (fk89/91) under 11:1 is workable?? If not I will be starting a gofundme page to cover my fuel cost,, |
Those cams need over 11:1 just to work. There is a difference between dynamic compression, where the cam plays a part, and static compression I'm sure you know the difference, if not you should just pay some one to build your engine,,,, oh wait......
_________________
There are no stupid questions, only stupid people,
68 Ghia
67 T-1
65 Notch
02 Mexican beetle
74 Thing
15 Long travel rail
07 Nomad
05 f-250 |
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[email protected]
Samba Member
Joined: August 15, 2002
Posts: 4394
Location: Brew City
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| Posted: Thu Jan 24, 2019 8:31 am Post subject: Re: Is 10.1 too high? |
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| offrdbus70 wrote: |
Hi all,
Been awhile since I posted. Opinions here. Rebuilding last years Powder Puff drag Ghia winning engine from last year and getting ready for this season.
I asked the head builder to kiss the heads when doing his valve job but now I have 47cc.
With a .054 deck and 74x94 I am 10.1 compression.
Car is used for drag racing and going to local shows. Occasional drive to work.
Norris 407s cam
Ported 044 heads 42x37.5
Dual Dell 40's
What do you guys think? Can I run 10.1 or will I ping?
Thanks! |
What are you setting your timing at? Whether it pings or not is dependent on multiple factors like timing, type of heads used, camshaft, CR, fuel type used, etc. It may come down to dialing your timing back for the drives and then advancing it for the racing and using higher octane fuel. Or, you may be able to run it the same for both and have no problems. Either way, I wouldn't worry about 10.1
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Cylinder Head Reference Sheet |
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Slow 1200
Samba Member
Joined: July 02, 2004
Posts: 2105
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| Posted: Thu Jan 24, 2019 9:56 am Post subject: Re: Is 10.1 too high? |
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looks like the 407S has 256 @050 and 280 advertised, not that far from a VZ25 but less lift
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mark tucker
Samba Member
Joined: April 08, 2009
Posts: 23937
Location: SHALIMAR ,FLORIDA
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| Posted: Thu Jan 24, 2019 1:17 pm Post subject: Re: Is 10.1 too high? |
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| mcmscott wrote: |
| 10:1 with a 407 is high, I would use CB's 2250 and leave everything else alone. |
thats the cam I run with 10.4 cr no ping at all.works great. |
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67Beetle2017
Samba Member
Joined: August 01, 2006
Posts: 399
Location: Pasadena CA
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| Posted: Fri Mar 08, 2019 2:59 pm Post subject: Re: Is 10.1 too high? |
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offrdbus70,
I asked the cam grinder at Norris (back in 82) about compression for the 407S
He said, "...the 407S needs high compression to work well. 10.0:1 can be run."
Norris also stated "...the 407S cam is more like an Engle W125 if one is comparing grinds."
"With correct springs, 407S can also be used with 1.25 rockers."
One of the keys to success is to make sure ALL of the sheet metal fits with no gaps or leaks.
Like Mark, I used 10.5:1 with this cam in my 1835 for over 8 years on a daily driver. No ping on premium.
I used dual 40DCNF's 32mm venturis 135 mains, 190 Air correctors, 55 idle jets. Over 28+mpg@ 60+mph. (we had a 55mph limit for a while)
This camshaft can make good power.
Great midrange from about 2500 to 5500rpm.
Dynoed in 1982 on Clayton dyno - 126 RWHP
Logged over 88,000 miles on that 1835. Retired the combination in 1990 for a 2110.
A little late but hope this helps. |
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