LQ4 off-road/daily build
04-11-2022, 11:59 PM
#11
You may also want to consider these cams from summit.
8727R1 https://www.summitracing.com/parts/sum-8727r1
8719R1 https://www.summitracing.com/parts/sum-8719r1
Or these from Texas speed.
https://www.texas-speed.com/p-8555-t...-camshaft.aspx
https://www.texas-speed.com/p-5002-t...-camshaft.aspx
8727R1 https://www.summitracing.com/parts/sum-8727r1
8719R1 https://www.summitracing.com/parts/sum-8719r1
Or these from Texas speed.
https://www.texas-speed.com/p-8555-t...-camshaft.aspx
https://www.texas-speed.com/p-5002-t...-camshaft.aspx
i like that tsp 208/214 cam, would probably do nicely in this jeep.
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afoggin112 (04-12-2022)
04-18-2022, 01:14 PM
#12
LS1Tech Sponsor
OP,
That's a nice Jeep you have there. You've received some great advice from the community.
We like the cam recommendation from @68Formula. Our SUM-8728R1 Big Torkinator would be a great fit here. Specs on it are .600/.585, 212/218, 110+ 3 with -5* of overlap. It's designed to make great torque from 2,000 on up and pulls well to 6,500 with our SUM-174004 .600" lift beehives. It'll have a steady lope with its -1* intake valve opening (IVO) but will be easy to tune and live with. With its increased lift it'll make more power/torque across the range than similar-sized cams with less lift.
Regarding raising compression. We like raising compression when possible. It will improve power/torque across the range. There are a few ways you can go about this in this scenario.
- You could find some .040" head gaskets such as the Cometic CGT-C5751-040. These will bump compression roughly 0.2-0.3 points. That would put you around 9.7:1 from the factory 9.4:1. The additional benefit of going to the .040" head gasket is the reduced quench. Dropping the quench distance into the optimal .035-.045" range promotes a better combustion cycle and reduces the chance of knock.
- Another option is milling the heads. Assuming this has factory 317 heads that have 71cc chambers. Milling .030" off the heads would take roughly 4cc away from the chambers giving you a 67cc chamber. With a .051" head gasket you would have around 9.8:1. Combining the .030" mill with .040" head gaskets would put you right around 10:1. Milling .030" off the heads is the most we recommend to retain alignment with the intake.
- Another route would be going to a flat top or dome piston. We have our Pro LS line of 2618 forged pistons. Looking at the pictures you provided it appears this LQ4 has the Gen 3 press-fit rods that use a .945" pin. If so we have 2cc flat tops in the standard 4.00" bore or .005" over in case the bores need cleaning up. With either piston option, .040" head gaskets, and .030" milled off the heads you'd be right around 10.6:1.
Regarding octane and compression. At 10:1 you'll be good with 87 and a good tune. With 10.6:1 we'd recommend 91 or better. You could run 87 but might have to be conservative on timing. Although, it's not a good idea to constantly pull timing if static compression is too high. We like taking advantage of higher compression with the proper octane but understand everyone has a different budget.
Let us know if we can be of any further assistance. We'll be happy to help!
That's a nice Jeep you have there. You've received some great advice from the community.
We like the cam recommendation from @68Formula. Our SUM-8728R1 Big Torkinator would be a great fit here. Specs on it are .600/.585, 212/218, 110+ 3 with -5* of overlap. It's designed to make great torque from 2,000 on up and pulls well to 6,500 with our SUM-174004 .600" lift beehives. It'll have a steady lope with its -1* intake valve opening (IVO) but will be easy to tune and live with. With its increased lift it'll make more power/torque across the range than similar-sized cams with less lift.
Regarding raising compression. We like raising compression when possible. It will improve power/torque across the range. There are a few ways you can go about this in this scenario.
- You could find some .040" head gaskets such as the Cometic CGT-C5751-040. These will bump compression roughly 0.2-0.3 points. That would put you around 9.7:1 from the factory 9.4:1. The additional benefit of going to the .040" head gasket is the reduced quench. Dropping the quench distance into the optimal .035-.045" range promotes a better combustion cycle and reduces the chance of knock.
- Another option is milling the heads. Assuming this has factory 317 heads that have 71cc chambers. Milling .030" off the heads would take roughly 4cc away from the chambers giving you a 67cc chamber. With a .051" head gasket you would have around 9.8:1. Combining the .030" mill with .040" head gaskets would put you right around 10:1. Milling .030" off the heads is the most we recommend to retain alignment with the intake.
- Another route would be going to a flat top or dome piston. We have our Pro LS line of 2618 forged pistons. Looking at the pictures you provided it appears this LQ4 has the Gen 3 press-fit rods that use a .945" pin. If so we have 2cc flat tops in the standard 4.00" bore or .005" over in case the bores need cleaning up. With either piston option, .040" head gaskets, and .030" milled off the heads you'd be right around 10.6:1.
Regarding octane and compression. At 10:1 you'll be good with 87 and a good tune. With 10.6:1 we'd recommend 91 or better. You could run 87 but might have to be conservative on timing. Although, it's not a good idea to constantly pull timing if static compression is too high. We like taking advantage of higher compression with the proper octane but understand everyone has a different budget.
Let us know if we can be of any further assistance. We'll be happy to help!
The following users liked this post:
afoggin112 (04-18-2022)
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