84 454 motor buildup

[red]

wont be starting this for a few more months but it will for sure be starting in oct-nov time frame. motor is currently in my k30 bolted to a th400 and np205. truck has been used as a workhorse and play truck its whole life so the bed is not in the best shape, and the cab corners/rockers/doors/fenders are all pretty rusty so will probably be pulling the drivetrain out and putting it into the next rig.

plans for the motor and requirements. staying carb, very simple and reliable, not to mention they are cheap and easy to work on. aiming for at least 500hp and 500ft/lbs of torque, though would like to be closer to 600 if possible (see other requirements). reliability, not going to be racing this motor, will spend the vast majority of its time in the low-mid rpm range. plan to keep this around for a long time so reliability is very important, dont want to have to rebuild this thing every few thousand miles. fuel economy, its a big block going into a crew cab pickup, suburban, or k5 blazer so fuel economy will not be great. was getting 11-12mpg around town (before the carb had to be replaced) with 35" tires, if i can get up to 14-15mpg i'll be very happy. budget on this project is a few grand, though nothing extravegant lol. also want this to run on pump gas so compression ratio cant be too high.

i'm fairly new at rebuilding a motor so input is greatly appreciated. one of the options that i'm considering is having the block bored .040 over and making it a stroker, should put it about a 490ci if my numbers are right. not sure which style pistons to go with (flat, dome, etc) or which crank would be needed.

for the top end i know that the stock intake manifold is pretty restrictive and the heads leave alot to be desired. can the stock heads be worked to meet my goals or would i be better off replacing them? i found this kit on summit for a decent price http://www.summitracing.com/parts/EDL-2095/ that could work, though if there are better ways to go my ears are wide open.


fuel system. the truck has a mechanical fuel pump, should i change over to an electric pump with a regulator to keep it down in pressure for the carb or stick with the mechanical? the carb i now have is a 800cfm edelbrock thunder series avs, simple to adjust and for the angles that i encounter offroad its one of the better ones to go with.

exhaust. will be getting a set of headers, however with the amount of options not sure which type to go with. thinking long tubes because of the torque benefits and the fact that i have the room for them. what size primary tube diameter though, 1 3/4" or 1 7/8"? and the collector, should it be 2.5" or 3"? will be a dual exhaust system with an H or X pipe if needed.




all input, ideas, help greatly appreciated.

 

[tinypeckerwood]

Sounds like you ned to be a little more realistic in your build and budget. To be honest with you, I would just go and buy a factory 502. The tow motor 502. You would be money ahead and have a warranty. A 600 hp BB is not that hard to build, it just won't be a good motor for a truck and your needs. You would be much happier with a 400 450 hp motor. That can be easily done with most of your parts you have. I would leave the stroke alone, use your stock crank. It is cheaper than buying a new crank. I would go with flat top pistons in the 9:1 area and zero deck the block. I would go with a mild, nothing crazy cam. And a decent set of after market heads, again not too large. By keeping things on the mild side you will increase the realiability of your engine. You want to build for torque not horse power. You want to aim for a torque peak around 3000 rpm. I would go with a mild edlebrock intake like the performer would be a great manifold for you. You don't need to spin this engine over say 5500 rpm. This will get your your best mileage and make a great torque engine. If you were going to build for some light weight car it would be a different story. In a heavy truck you want good torque. You would have a grate truck with say 400 hp and 500 ftlbs, way more than you had originally. probably like 200 hp and 350-400 ftlbs.
The last time I was kicking this idea around, I priced everything out and bought a 502 for my suburban.

 

[ak diesel driver]

for how you are going to use it you def want torque. If you don't go the 502 then definetly stroke it that's where you build your torque.

 

[red]

the budget i'm aiming for is around 4-5k, i realize though that as with most projects that will probably be surpassed. so 500ft/lbs of torque would be a more realistic goal then? just did a quick search online and found this crate 502 http://www.crateenginedepot.com/store/product1.aspx?Product_ID=14 for a little more than my aiming budget but within reach so definetly an option. would still need an intake and headers to go with that option so would probably be right over the 6k cost. this would also give me a 4 bolt instead of the 2 bolt that i have, and a newer block design.

could rebuild the motor and upgrade the heads and cam for right around the power levels i would be looking for, at a cheaper price than the crate, or make it a 496 stroker with a 2 bolt block for around the cost of the 502 crate.

yall got me interested in the 502 option haha

 

[red]

after looking over available money for this project when i return think i will limit the work to top end upgrades. motor that will be getting the work done has about 78,000 miles on it

 

[tinypeckerwood]

I would still take some measurements, and do a compression test. If then, all is good, I would still do new bearings and rings.

 

[red]

would be a good idea. any idea what #'s for the cylinder heads would be a good option for my build? also what is the maximum compression ratio that regular pump gas can run on, 9:1 or is it lower?

 

[tinypeckerwood]

I would stay on the conservative side for the heads and cam. A little bigger than factory on both would be good. I would keep the compression ratio right at the 9:1 mark. You could go more, but there is a lot of variables to do so safely. This is what I would build for a BB. These are not exacts, just ball park #'s for a good all around engine.

cam in the area .500 - .600 lift
around 220-230* duration
9:1 comp
moderate runner size heads
dual plane intake
long tube headers
750cfm carb

This should have you right around 425 - 450 horse power and about the same torque.

 

[malibu795]

i did this with 9:1 OEM heads 2.065/1.88 valve 049 cast heads ported.
edel pertmance intake, tube headers, dual 2.5 exhaust, msd ign system, 600cfm carb, summit 208/214* @.050 .475/.500 camshaft..
i could have gone to 2.19 intake but didnt.... and little bit bigger camshaft

 

[tinypeckerwood]

i did this with 9:1 OEM heads 2.065/1.88 valve 049 cast heads ported.
edel pertmance intake, tube headers, dual 2.5 exhaust, msd ign system, 600cfm carb, summit 208/214* @.050 .475/.500 camshaft..
i could have gone to 2.19 intake but didnt.... and little bit bigger camshaft

Those are decent numbers, probably makes for a decent driver. What size is this engine?

I just realized these are chassis dyno numbers and not engine dyno numbers! They are really good numbers!

 

[malibu795]

060 over 454= 468

does 19-20mpg @75 on the freeway in my malibu wagon weighs 4000lb

figure 15-20% drive train lose and its 350-370hp with 500-525lb at the crank

 

[tinypeckerwood]

060 over 454= 468

does 19-20mpg @75 on the freeway in my malibu wagon weighs 4000lb

figure 15-20% drive train lose and its 350-370hp with 500-525lb at the crank

sounds like a great motor. It must have an OD trans behind it to get that kind of mileage from a BB.

 

[malibu795]

2.41 gears and a 26"tire

 

[red]

no kidding on the fuel economy haha.

very good numbers, what head specs are you running?

 

[malibu795]

no kidding on the fuel economy haha.

very good numbers, what head specs are you running?

OEM 049 cast heads with 2.065 intake and 1.88 exhaust (i cleaned up all the ccasting flash in the runner and around the valve bowl) k-motion springs comp 1.72 roller tip rockers arp studs

the open chamber with 10cc dome piston form speed pro hypers re-con the rod cut the crank edel 3606 intake first gen preformer intake
high volume oil pump 80gph summit mech fuel pump

 

[red]

looks like plans will be changing slightly, still same goals for the motor just a different truck. 87 chevy land yacht (in my garage).

question, which is more fuel efficient, the carb or tbi 454? if the carb can get better fuel economy i'll probably pull the tbi out of the 87 tow rig and put a carb and better intake on it in august so i wont be spending as much for fuel when i drive down to Texas in early sept. if the tbi can get the best fuel economy then does anyone know where a better tbi intake manifold is available?

fyi the new carb is an 800cfm

 

[DieselCash]

Two trucks back I had a 1998 Chevrolet K3500 Crew Cab Dually with a fuel injected 454, behind a auto trans and 4X4.

The best fuel economy I ever got was 11.5 mpg.

I tried a few things to improve the fuel economy and nothing really helped. I redid the exhaust to true duels and two mufflers, put a K & N intake system, and a superchips.

No matter what I did it never improved. The bright side is also no matter how I drove it never went down! :thumbsup:

 

[red]

11.5 would be just fine, problem is my friend who is borrowing the truck until i'm back in the states got 6mpg on the camping trip this weekend pulling about a 5-7k pound trailer. was probably going the speed limit (75mph) which would explain alot but i'll find out later tonight exactly what his speed was.



for headers looking at maybe these http://www.summitracing.com/parts/BIG-31530FLT/ or some hedman street headers

 

[red]

alright fuel economy issue explained, he was going the speed limit lol. 454, no overdrive, 4.56 gears and 75mph in the high altituded up in Utah=6mpg, ouch haha but sounds normal.

 

[red]

reviving an old thread here instead of starting a new one, wow how plans change over 6 months expecially vehicle projects. the crewcab dually is almost done getting a cummins 12 valve transplant but i found a use for the 454.

picked up a 1986 k5 blazer that had a 350, sm465, and np208 in it. trans and t-case are doing just fine but the 350 decided it wanted to develop a very harsh rod knock really fast, sounds like it was about to throw the rod out the block (happened at highway speeds). so seeing as i have a 454 lying around that was working just fine, i decided to begin swapping the 454 into the blazer. before it goes in its getting new gaskets, double roller timing chain, and some basic upgrades consisting of a set of long tube headers and an edelbrock intake to go with the 800cfm carb thats on it. would also like to change the cam out for a one better suited to what the truck will be doing, rock crawling with some mudding and very little on-road driving.

i have already replaced the oilpan and head gaskets, timing chain and headers should be here by wednesday.

k5 blazer

350 and 454 sitting by each other

my question is, what would be a good duration and lift for the cam? operational use will be from idle-4k rpm's with most of the time being under 3500. building for torque, the less i have to use the skinny pedal and be able to crawl up the rocks the better.