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Re: How much compression is too much? [Re: '72CudaRacer] #2464556
03/11/18 01:51 AM
03/11/18 01:51 AM
Joined: Jan 2003
Posts: 6,591
Canton, Ohio
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Sport440 Offline
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Canton, Ohio
No real advantage with that much compression, over say around 15.1 comp but if its together as stated you can run it the way it is, just use the correct fuel. Your wider LSA will help with the extra comp. I would just leave it as is and then on next tear down, address the comp issue.

Diesels run up to 25.1 ratios, fx high rpm 18000 rpm gas motors run 17.1 comp to assist at that rpm. So you are at Top level comp with your motor.

Also, for Just a Bracket motor, you really don't need a 620 ci as well. To me you have a Max built et motor. Send it to me and I will send you a reliable 448 Bracket motor. No Charge. up

Re: How much compression is too much? [Re: '72CudaRacer] #2464581
03/11/18 03:35 AM
03/11/18 03:35 AM
Joined: Jan 2008
Posts: 2,363
Cotati, CA
Dave Hall Offline
top fuel
Dave Hall  Offline
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Cotati, CA
Run VP Q16 and go haul a$$ with it.

Re: How much compression is too much? [Re: '72CudaRacer] #2464751
03/11/18 02:29 PM
03/11/18 02:29 PM
Joined: Apr 2005
Posts: 2,128
Salt Lake City
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camastomcat Offline
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Salt Lake City
I think it's a 2.400 intake valve. I ran 16.3-1 with my B1/MC 572 with Sonoco Maximal and it made good power. The only question is the 4.600 bore and whether toy can get the head gasket to stay sealed.

Re: How much compression is too much? [Re: '72CudaRacer] #2464760
03/11/18 02:42 PM
03/11/18 02:42 PM
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Posts: 4,243
Charlotte, North Carolina
sgcuda Offline
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Charlotte, North Carolina
Are you on 4.800" bore centers? That's a lot of compression to seal a head gasket with not a lot of room between bores.


[image][/image]
Re: How much compression is too much? [Re: sgcuda] #2464825
03/11/18 05:25 PM
03/11/18 05:25 PM
Joined: Jan 2003
Posts: 6,591
Canton, Ohio
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Canton, Ohio
Originally Posted By sgcuda
Are you on 4.800" bore centers? That's a lot of compression to seal a head gasket with not a lot of room between bores.


The Koleno blocks are on a 4.8 centers, with a 4.60 bore that gives a .200 space center of sealing surface.

Re: How much compression is too much? [Re: camastomcat] #2464827
03/11/18 05:27 PM
03/11/18 05:27 PM
Joined: Aug 2009
Posts: 2,036
Mooresburg, Tn
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'72CudaRacer Online content OP
top fuel
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Mooresburg, Tn
Originally Posted By camastomcat
I think it's a 2.400 intake valve.

You are correct, it's real big!

Brian

Re: How much compression is too much? [Re: '72CudaRacer] #2464899
03/11/18 08:24 PM
03/11/18 08:24 PM
Joined: Jan 2017
Posts: 288
Nevada
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merpar Offline
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Posts: 288
Nevada
Read an article years ago in National Dragster, written by Warren Johnson. He did very extensive testing on compression ratio's. He said anything over 16:1 did not make any more power.
Now my opinion: As gomangoCuda said, switch to methanol. It will love the 16:1

Re: How much compression is too much? [Re: Dave Hall] #2464901
03/11/18 08:26 PM
03/11/18 08:26 PM
Joined: Aug 2003
Posts: 1,573
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KOS Offline
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KOS  Offline
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Posts: 1,573
Originally Posted By Dave Hall
Run VP Q16 and go haul a$$ with it.


my sediments exactly.........just make sure carb is calibrated for it.

Last edited by KOS; 03/11/18 08:27 PM.
Re: How much compression is too much? [Re: Dave Hall] #2464904
03/11/18 08:36 PM
03/11/18 08:36 PM
Joined: Feb 2005
Posts: 20,116
PA.
pittsburghracer Online work
"Little"John
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"Little"John

Joined: Feb 2005
Posts: 20,116
PA.
Originally Posted By Dave Hall
Run VP Q16 and go haul a$$ with it.




It’s one thing to run a heads up program with usually 4 rounds max compared to a bracket program with 7 or more rounds. How much does Q16 cost a gallon again. I think 55 gallons of alcohol was around 165.00
Last year.


1970 Duster
Edelbrock headed 408
5.984@112.52
422 Indy headed small block
5.982@112.56 mph
9.42@138.27

Livin and lovin life one day at a time




Re: How much compression is too much? [Re: '72CudaRacer] #2465339
03/12/18 06:37 PM
03/12/18 06:37 PM
Joined: Jan 2003
Posts: 30,947
Oregon
A
AndyF Offline
I Win
AndyF  Offline
I Win
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Posts: 30,947
Oregon
Q16 is expensive and you have to use a lot of it. It is also really foul smelling and will eat away at the carb and the fittings over time. I did a Q16 engine for awhile and have no desire to go back to it.

But it all depends on what the owner wants to do. If it is a bucks up program with a crew chief and a tire wiping monkey in the pit crew then who cares. They can handle all of the maintenance and the driver gets to go down the track a little faster.

Re: How much compression is too much? [Re: '72CudaRacer] #2465361
03/12/18 07:26 PM
03/12/18 07:26 PM
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Posts: 9,963
Frostbitefalls MN (Rocky&Bullw...
gregsdart Offline
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Frostbitefalls MN (Rocky&Bullw...
Before running alky, be sure and check with some people that have put a lot of runs on a B1 big motor with that compression. It would be rather expensive if my info proved correct frown


8..603 156 mph best, 2905 lbs 549, indy 572-13, alky
Re: How much compression is too much? [Re: '72CudaRacer] #2465366
03/12/18 07:35 PM
03/12/18 07:35 PM
Joined: Aug 2003
Posts: 1,573
K
KOS Offline
pro stock
KOS  Offline
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K

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Posts: 1,573
I've been running Q16 since 08/09 and never had any corrosion issues mind you I drain it usually after every race or after a week at max.also at that level of performance I don't think cost of fuel would be a major concern and for the performance gain definitely worth it.

Re: How much compression is too much? [Re: '72CudaRacer] #2465544
03/12/18 11:36 PM
03/12/18 11:36 PM
Joined: Mar 2006
Posts: 9,791
MI, usa
dvw Offline
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Posts: 9,791
MI, usa
Why not Renegade Pro 116 + ? Last price I had at the end of the year was just over $10 gallon when bought by the drum. Not oxygenated but plenty of detonation resistance.
Doug

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