Nikwho
Well-Known Member
- Joined
- Jan 8, 2019
- Messages
- 284
- Reaction score
- 254
Hey guys,
I'm in the beginning stages of my 468 engine build. I've set a goal of 600-650 HP, as I believe that is a realistic and relatively safe goal (reliability-wise), given my general budget. I want to run on premium pump gas. I don't have a hard budget for the build, but it is not going to be a no expense spared deal. Im fine commiting another $3,000-$5,000 into this ordeal, from where I am at now, sitting on most of the parts, with most machine work done. I want to find a happy medium between dollars, reliability and horsepower. So, setting a goal of having an HONEST 600+ HP BBC, I am looking for some guidance.
What I have:
I've got a freshly machined '72 Mk. IV BBC block. Two bolt mains, studded with ARP main studs. Forged 4" stroke crank, 4.310" bore, Speed Pro forged pistons(L-2465F 60) with 27.1cc dome. 049 heads. Heads also machined. New guides, valve surface machined, but don't have valves or valvetrain components selected as of yet. I also have not purchased rods. Im looking at running these Eagle H-beam forged rods:
So, I have my short block, less a set of rods (6.135", to run the pistons that I have) and balancing. I already have the machined 049 heads. I have not measured to see what size valves the heads were cut for. If I need to go oversize to meet my goals, I'll pass that on to machinist, come time to have the heads built. Without knowing the exact deck height of this setup, or the exact cc's of the combustion chambers, I believe that I am looking at roughly 10.14:1 static compression.
So, with the collection of parts that I have, and my general goal of 600-650 real world HP, where does this put me? I want to run thru transom exhaust/headers. Want to steer away from OTT headers.
So, this leaves me to cylinder heads (valve sizes and other valvetrain component selection), camshaft type/grind selection, intake selection and carb selection. I should be able to meet my HP goal with a single 850 cfm carb, though I have two matching Quick Fuel 650's and two matching Edelbrock 1405 600 cfm carbs, so those are an option that would save money in a dual carb configuration.
Camshaft choice? Assuming that a hydraulic flat tappet is less likely to get me to my goal. I'd be fine running a solid flat tappet cam, if it will allow me to meet my goal, with a fair degree of reliability. Im okay with frequent valve adjustments. Solid or hydraulic rollers are a more expensive option, but can add some reliability and less frequent valve lash adjustment, if hydraulic. Assuming that a high quality roller setup is going to run $1,500+, I'm okay with a flat tappet cam, if it will meet my goals.
I had been looking at this Howard's cam, but I'm not sure that it would produce the 600+HP that I am reaching for:
Intake:
I had thought that with my 468" deal, and 600-650 HP goal, I'd need to reach this at a slightly higher RPM? Tunnel ram, dual 650cfm carb setup? Perhaps a Victor and single 850cfm carb?
I'm still in my initial planning stages. Looking for guidance to steer me in the general right direction. Don't want to overbuild, nor spend money twice, by replacing the wrong components.
Any help from you far more experienced guys would be so greatly appreciated!
I'm assuming at this point that I'll end up running this in my 1974 18' Tahiti. It has a 12JC pump and hydraulic Place Diverter. Willing to change impeller as needed to optimize performance.
I would like to be able to pull a tube or skier/wake board. Looking for a reliable family hot rod to run primarily on the Colorado river. Mostly Laughlin to Havasu, and the Parker strip. Also will see various lakes occasionally.
Thanks in advance for any help!
Nik
I'm in the beginning stages of my 468 engine build. I've set a goal of 600-650 HP, as I believe that is a realistic and relatively safe goal (reliability-wise), given my general budget. I want to run on premium pump gas. I don't have a hard budget for the build, but it is not going to be a no expense spared deal. Im fine commiting another $3,000-$5,000 into this ordeal, from where I am at now, sitting on most of the parts, with most machine work done. I want to find a happy medium between dollars, reliability and horsepower. So, setting a goal of having an HONEST 600+ HP BBC, I am looking for some guidance.
What I have:
I've got a freshly machined '72 Mk. IV BBC block. Two bolt mains, studded with ARP main studs. Forged 4" stroke crank, 4.310" bore, Speed Pro forged pistons(L-2465F 60) with 27.1cc dome. 049 heads. Heads also machined. New guides, valve surface machined, but don't have valves or valvetrain components selected as of yet. I also have not purchased rods. Im looking at running these Eagle H-beam forged rods:
CHEVROLET Eagle Specialty Products CRS61353D Eagle H-Beam Connecting Rods | Summit Racing
Free Shipping - Eagle H-Beam Connecting Rods with qualifying orders of $109. Shop Connecting Rods at Summit Racing.
www.summitracing.com
So, I have my short block, less a set of rods (6.135", to run the pistons that I have) and balancing. I already have the machined 049 heads. I have not measured to see what size valves the heads were cut for. If I need to go oversize to meet my goals, I'll pass that on to machinist, come time to have the heads built. Without knowing the exact deck height of this setup, or the exact cc's of the combustion chambers, I believe that I am looking at roughly 10.14:1 static compression.
So, with the collection of parts that I have, and my general goal of 600-650 real world HP, where does this put me? I want to run thru transom exhaust/headers. Want to steer away from OTT headers.
So, this leaves me to cylinder heads (valve sizes and other valvetrain component selection), camshaft type/grind selection, intake selection and carb selection. I should be able to meet my HP goal with a single 850 cfm carb, though I have two matching Quick Fuel 650's and two matching Edelbrock 1405 600 cfm carbs, so those are an option that would save money in a dual carb configuration.
Camshaft choice? Assuming that a hydraulic flat tappet is less likely to get me to my goal. I'd be fine running a solid flat tappet cam, if it will allow me to meet my goal, with a fair degree of reliability. Im okay with frequent valve adjustments. Solid or hydraulic rollers are a more expensive option, but can add some reliability and less frequent valve lash adjustment, if hydraulic. Assuming that a high quality roller setup is going to run $1,500+, I'm okay with a flat tappet cam, if it will meet my goals.
I had been looking at this Howard's cam, but I'm not sure that it would produce the 600+HP that I am reaching for:
Howards Cams 510041-12 Howards Cams Street Force 4 Hydraulic Flat Tappet Camshafts | Summit Racing
Free Shipping - Howards Cams Street Force 4 Hydraulic Flat Tappet Camshafts with qualifying orders of $109. Shop Camshafts at Summit Racing.
www.summitracing.com
Intake:
I had thought that with my 468" deal, and 600-650 HP goal, I'd need to reach this at a slightly higher RPM? Tunnel ram, dual 650cfm carb setup? Perhaps a Victor and single 850cfm carb?
I'm still in my initial planning stages. Looking for guidance to steer me in the general right direction. Don't want to overbuild, nor spend money twice, by replacing the wrong components.
Any help from you far more experienced guys would be so greatly appreciated!
I'm assuming at this point that I'll end up running this in my 1974 18' Tahiti. It has a 12JC pump and hydraulic Place Diverter. Willing to change impeller as needed to optimize performance.
I would like to be able to pull a tube or skier/wake board. Looking for a reliable family hot rod to run primarily on the Colorado river. Mostly Laughlin to Havasu, and the Parker strip. Also will see various lakes occasionally.
Thanks in advance for any help!
Nik