but stock head for stock head.....

these are assumed to be stock, maybe milled flat for reuse.

 

Stock for stock, the smaller combustion chamber of the 241 (66.5cc) raising the cr to ~10.8 is the only advantage of it over a 317. Factor in port work and that is a different story. I am currently running some mildly ported 241 on my truck.

Give the truck some fuel and fix the tune and it should run circles around a tuned 5.3 even with the less than optimal head/cam combo. Should have lots of low end torque with the ci, cr and small head.

 

Waiting on a wideband..
i thought the 241s were the junk head.. i was mistaken.. i didnt know they were that close to the 243s..

 

So this LQ9 should be ~10.8 CR with stock 241s?

 

A true LQ9 with flat top pistons is rated at 10:1 - 1 with 317

317 is around 72 CC

241 is around 64 cc

So Your going to be closer to 11.1 CR

If the heads are milled .010 to clean it up it could be more like 11:3-1 CR.

I have only had 2 Flat top piston motors apart and they averaged any were from .006-.008 above the deck.

The cam choice is not the greatest but with good tuning and fuel should still pull on that 5.3 with a cam.

HTH

 

806 are the junk LS1 heads replaced by the 241 on LS1s in 99. IIRC 241 are 66cc and 243 are 64cc. 66cc is what I based the 10.8 cr off of.

 

I know guy in fort worth that has a LQ9, 241 heads, and a big donkey cam. Made 401 to the wheels this past summer.

FWIW another guy has a LS1, stock 243 heads, smaller cam. This combo made 422 to the wheels. Lol both tuned my same tuner that is pretty popular in the area.

 

Ahh thats the head i was thinking about!!

 

Found this today.. i thought the 241 head was smaller CC than 243?




Application GMPartNumber Combustion Chamber Volume (cc) Intake Port Volume (cc) Exhaust Port Volume (cc)
1997~1998 LS1 12559853 66.67 200 70
1999~2003 LS1 12564241 66.67 200 70
2001~2003 LS6 12564243 64.45 210 75

1999+ L59, LR4, 12559852/
LM4/LM7 12561706 61.15 200 70

1999~2000 LQ4 (Iron) 12561873 71.06 210 75
2001~2003 LQ4 (Alum) 12562317 71.06 210 75
2002~2003 LQ9 12572035 71.06 210 75

 

No, 241 has bigger combustion chamber than 243.