Cam/Compression help on 472

Go down

Cam/Compression help on 472

Post  bbfguy1 on September 10th 2018, 4:42 pm

I have C9VE block that is .060 with an uncut deck, so it should be 10.300 or there about. I also have a set of cast .060 Silvolte (#1143) pistons, which show a compression height of 1.760 on the box. The heads I have and want to use, are a set of C8VE's that have a nice port job with good stainless valves at OEM size;
Int 2.08(Ferrea 5000 series) and Ex 1.65 (Comp products valve). The heads have been setup with Comp 924 springs, ARP studs, guideplates and have been milled to a 70cc chamber. The heads were milled to 70cc ,for another project that never materialized.

My worry here, is to much compression for 100% 93 octane fuel. I figuring, even if the heads weren't milled, compression would already be pushing 10.0:1 and with my heads at 70cc, it would be a good bit over 10.0:1 The cam that I'm eyeing is the Lunati 61602 (219/227@.050). Do you guys think this is too far on the edge with compression and smallish cam to be a nice trouble free driver? Car is 1973 Torino with C6 and 2.75:1 gears.

I have the option of using a D1VE block but I would have to have it bored .060, which it doesn't need. This C9VE block cleaned up fine at .060, that is why I would like to use it, but I don't want a finicky engine, due to compression. Thanks in advance!

bbfguy1

Posts : 27
Join date : 2009-09-14

View user profile

Back to top Go down

Re: Cam/Compression help on 472

Post  STR-LGL-70 on September 10th 2018, 8:40 pm

I think while it is apart maybe switch to a cam with some more duration, should be of some help & not too much $$. Is E-85 available in your area? Also not sure of converter you have but with 2.75 gears lugging the engine will not help the situation.
Sheldon G.
avatar
STR-LGL-70

Posts : 160
Join date : 2009-08-06
Age : 55
Location : Daytona FL

View user profile

Back to top Go down

Re: Cam/Compression help on 472

Post  Paul Kane on September 11th 2018, 1:12 pm

10.3:1 compression ratio, yes it will run on 93 octane fuel, long block capable of about 400hp depending on the bolt-ons.

The caveat is the full-size car with its 2.75 axle ratio.  I think it will drive fine as a daily driver on 93 octane, however under heavy loads it will probably rattle.  You are better off with the C9 block than the undecked D1 block.

Personally I’d run the recipe just as proposed, less so for a customer build.
avatar
Paul Kane

Posts : 820
Join date : 2009-09-15
Location : San Francisco Bay Area

View user profile http://www.highflowdynamics.com

Back to top Go down

Re: Cam/Compression help on 472

Post  rmcomprandy on September 11th 2018, 5:34 pm

bbfguy1 wrote:

My worry here, is to much compression for 100% 93 octane fuel. I figuring, even if the heads weren't milled, compression would already be pushing 10.0:1 and with my heads at 70cc, it would be a good bit over 10.0:1  The cam that I'm eyeing is the Lunati 61602 (219/227@.050). Do you guys think this is too far on the edge with compression and smallish cam to be a nice trouble free driver? Car is 1973 Torino with C6 and 2.75:1 gears.  


I think the duration at .050" is fine but, personally I would use a cam with a bit more intake seat duration and tighter separation for helping the detonation resistance somewhat.

rmcomprandy

Posts : 5124
Join date : 2008-12-02
Location : Roseville, Michigan

View user profile http://www.rmcompetition.com

Back to top Go down

Re: Cam/Compression help on 472

Post  bbfguy1 on September 13th 2018, 8:22 am

Thanks for the input and advice! For grins, I got on the phone with Bullet Cams yesterday and they came up with a custom grind that is below. It's a bit more cam than I would like and will require a mild 2200-2500 torque converter but I was told, it should still make vacuum for brakes/AC and help with resisting detonation. Randy, is this more of the type of cam that you had in mind?


279/287 Adv.
227/235@.050
Int. .530/Ex. .530
LSA. 109

bbfguy1

Posts : 27
Join date : 2009-09-14

View user profile

Back to top Go down

Re: Cam/Compression help on 472

Post  rmcomprandy on September 13th 2018, 9:29 am

bbfguy1 wrote:Thanks for the input and advice! For grins, I got on the phone with Bullet Cams yesterday and they came up with a custom grind that is below. It's a bit more cam than I would like and will require a mild 2200-2500 torque converter but I was told, it should still make vacuum for brakes/AC and help with resisting detonation. Randy, is this more of the type of cam that you had in mind?


279/287  Adv.
227/235@.050
Int. .530/Ex. .530
LSA. 109

Not really but, it will work fine.

rmcomprandy

Posts : 5124
Join date : 2008-12-02
Location : Roseville, Michigan

View user profile http://www.rmcompetition.com

Back to top Go down

Re: Cam/Compression help on 472

Post  cletus66 on September 13th 2018, 9:48 pm

bbfguy1 wrote:Thanks for the input and advice! For grins, I got on the phone with Bullet Cams yesterday and they came up with a custom grind that is below. It's a bit more cam than I would like and will require a mild 2200-2500 torque converter but I was told, it should still make vacuum for brakes/AC and help with resisting detonation. Randy, is this more of the type of cam that you had in mind?


279/287  Adv.
227/235@.050
Int. .530/Ex. .530
LSA. 109

You should probably call him and ask him.  I did, and he delivered EXACTLY what I was asking for.  




The finest in custom engine building for all venues ...!
Selling those Parts & Supplies from companies I use ... 1 (586)909-1591 ... fax 1 (586)771-2930

CUSTOM ground camshafts
Carburetor modifications for specific applications
CNC porting
avatar
cletus66

Posts : 815
Join date : 2009-08-08
Age : 52
Location : Charles City, Virginia

View user profile

Back to top Go down

Back to top


 
Permissions in this forum:
You cannot reply to topics in this forum