Thread: Need help with 454

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Hi my name is Ken. I am new to this site. I have been watching for a while and you guys seem to really know your stuff and I could use some help. I am working on a 454 out of and 84 suburban and I'm not sure if I can use the same Pistons valve springs and etc. with a bigger cam and bigger carb. Motor had about 60,000 miles on it and it had an oil cooler transmission cooler and everything looks to be in very good shape. It's been in about 30 years since I worked on a motor other than changing parts just to keep the daily driver going. Well now my kids are older, and I have a little more time and a couple extra bucks to do what I want. So building a hot rod is what I want to do.

Thanks for any help. It's really appreciated

ken

Ken,
You are going to want to research your springs according to which cam you use. Things like coil bind height and and clearance at maximum valve lift are going to be new factors.....really research what it is you want to do. Start with a realistic goal and come up with a plan of how to get there. Doe sit fit the budget for time and money? Can parts be put back into service or do they need reconditioned? Remember that bigger is not always better in carbs and cams. The basic idea is to increase cylinder "fill", the amount of air fuel mixture during the intake cycle. The most overlooked way to do this is port velocity. More air/ fuel can be stuffed into the cylinder if it is moving faster.The increased density within the cylinder raises the cylinder pressure which when ignited creates more power. Cylinder pressure can also be increased through cam timing. The point at which the intake valve closes determines the usable part of compression ratio.

I know I am throwing a few ideas at you in really vague terms, but it is up to you to research and learn more. These guys are really knowledgeable but do yourself the favor of researching as much as possible before buying any parts. Do not modify anything until you know why, and where it fits into your plan.

Thanks threearmsinjune I appreciate your help. the problem I'm having researching anything is that all the magazines that I have been reading are about selling products. Don't want to buy stuff if I don't need to. How do I learn, what size cam and carb to use on a certain motor

thanks again ken

justhavenfun hi Im new on here also,try calling Summit Racing or Jegs,Summits tech line 1-330-630-0240 jegs has on also just dont have the number in frt of me. have your cams info in frt of you, lift, etc. and what cfm the carb is and they will let you know what springs ,etc you need or dont need.If its just like the edelbrok performer series stuff you should be allright. hope this helps you a little.

Research the math! Learn about the process and machine tolerances so that you do not have to take a salesmans word for it. Rather than calling the phone bank over at summit try calling the tech line of the cam manufacturer for example. If you want to learn about a specific area or product talk to the ones who do it every day, and then talk to another one. Get a few opinions and points of view. Then it is time to take what you have learned and think for yourself.
Tech articles in magazines are rather product specific. Try your local bookstore/library. Look for books on engine performance math and theory. I know it sounds scary, but most of these books do a fairly decent job at explaining the basics. Your basic parameters of the engine will depend on how you intend to put the 454 to use. The suburban is going to be a worker so you dont want to get crazy with the motor. You most likely wont be looking for power at high RPM, mostly off idle to 3000 maybe 3500. I assume that you intend to use mid-grade gasoline or higher, so you will be generally limited on your compression ratio to about 9.5 maybe 10 or so. The power band and compression ratio are good general ideas to consider when looking at a cam and fuel delivery system. The RPM use will determine the size of the carb, too big of a bore will slow down the velocity and not live up to the potential of the cam/head. Too small will suffer on the top end where it will not keep up with the airflow requirements. Personally I would favor the smaller bores for bottom end if you are looking at a working class motor, but definitely speak with the manufacturers with some hard info on your intentions.

threearmsinjune and 55Rat thanks a lot for all your info. It really helps. I'm not real knowledgeable about the numbers and so forth. I am on to way to library now to see if I can get a book so I can learn a little more. And then I'll probably be calling tech line. Again, thanks a lot for all the help I have learned a lot just from reading stuff on all the other threads I really appreciate your help. Thanks again ken

You can do it but these motors really have lame compression. I used a set of Speed Pro cast pistons with a .125 dome and stock heads in my 82 454 and it ran great. Clearance was fine with a .550 lift cam. This was just a good old backyard rebuild, but I made sure all the clearances were within specs. I never had it dyno'd, but it had plenty of power in my 70 Monte Carlo. You don't have to spend a ton of cash for a decent street engine if you just take your time and pay attention to the details.

falconvan

thanks for the input. It will help a lot

ken