Hey I recently purchased a running 454 out of a '73 chevy 1 ton pick up that was purchased from a local farmer's estate. The engine ran great - very smooth & no smoke. I took a close look at it a few nights ago and discovered that it had been remanufactured by a firm named Sequel Corp. The carb is a remanufactured Qjet with a date tag of 2006. I tore the engine down today, and found that while it is in excellent condition, it has been bored .060, and has a cast crank & 2 bolt mains. I bought the engine to use as a core for building a serious street/strip engine - 12 1/2:1 compression, rectangular port heads, solid lifters/cam. Will the fact that the block has been bored .060 have any negative effect? Will I be good with the cast crank & 2 bolt mains? I plan on running the engine at 5500 - 6000 RPM max. I'm hoping that the fact that the engine has had a fairly recent rebuild will allow me to get away with a hone and reduce my planned machine costs. Thaks in advance for your help!
Look at www.speedomotive.com Most of their engines are .60 over. I had one of their 500 hp engines and it ran great. Cast crank but forged pistons. Their web-site used to have a dyno sheet attached but I haven't been there in awhile.
I would not hesitate to use that engine...60 over is not too bad and a cast crank should be OK for your rpm range...I've done it!!
Awful lot of compression for a cast crank.What you are doing is similar to a GM factory Ls6-Ls7 engine,4 bolt mains,7/16" rods and a steel crank.Maybe something to ponder going with a little less compression or upgrading to some better bottom end parts.The 2 bolt block will be fine but maybe stud the mains.If you build it with what you have definetly use a rev limiter or i am pretty sure that cast crank or stock 3/8" rods will be in peices shortly.
I'm not a big fan of overboring any engine just to make it bigger cubes. And for damn sure not a 454 as the cylinders are shit from the factory and prone to core shift. Look at the pics as this is a busted cylinder from a 454 and all of the pieces came from the same cylinder !! I VOTE NO !!! If I was trying to make big power I would bore the block as little as possible and add some stroke. Take a look at the pics and you decide !! JMO >>>>.
....might be worth a sonic check of the bores before deciding? If you can build the engine for a relatively low cost (under 2k) then you might go for it. Although a serious street/strip engine with that much compression probably wants a cam that wants to work at quite a bit higher rpm than you plan, and that would mean you'd want to run a steel crank in it (along with rods and pistons capable of withstanding the rpm). It would make a nice 5500 rpm street/strip engine, about 500 hp, with a hydraulic cam and less compression.
I used to run all kinds of BBC combinations. For the RPM range, you're good with the 2 bolt mains. I agree with wannadrag on the rods, put in a set of 7/16". The easy solution for the rpm, is to install nothing more radical than an L-88 cam, this will keep you from revving any higher than needed as it will fall flat before any rods want to exit the block. .60 over is nothing to worry about, that's almost 'normal'. On the side, I wouldn't even bother with the rec port heads, find a good set of 74 castings. They flow great and will be all you need with the cam/block limitations. The rec ports wll cost you more than you need to spend....all for nothing. Just my opinion.......
Thanks for all the input! Frank - I thought that "74" casting heads were rectangular port L88/ZL1/LS6 aluminum heads?
Sorry, I'm just talking about a set of oval port heads that were cast in 74. GM did something in the combustion chamber with the quench area to deal with emissions, a stock set of these flow real good. One of the cars I used to run had a 402, oval port heads, 2 bolt mains, L-88 cam, 650 holley and it ran 11.30's. Not mind numbing times, but respectable for what it was. 4 bolt BBC and rec port heads are highly over-rated when it comes to street/strip combo's.
For the RPM range you are running, it would be fine. I would run oval port heads however, less compression, and stud the mains. Retangle port heads and a solid lifter cam are not needed at the RPM level you are looking at. Both will want to make power at higher RPM. I would sonic check the block however and how much wall thickness you have. Some 454's can go 1/8" over. If this is a thick block I would have problems with that much compression - but chances are its not.
my old race motors were all 468's... they were usually steel crank, 2 bolt mains, Corvette pump,pan,steel gears and nylon chain. Usually used TRW 12.5:1 pistons, stock dimple rods and ARP bolts. Cam was a 748/680 roller from comp cams, Harland Sharp rockers. Tranny was a buddie built Glide with Coan internals and Brake, 6000 convertor. Had 2 sets of heads ,1 oval port (as mentioned above) and 1 set of L-88's. Nothing special done tothem except portmatching, 219 intakes and 188's for exhaust Car went 9.30's with oval ports and 8.80's with alum. heads...I did run Alky Hilborn for indiction... So to answer the question...I'd run it ...Change crank, goodbolts, lower compression, get a Good cam,and she'll live for quite a while. 2 things to remember..There is no substitute for cubic inches Good preparation usually brings great results Who did I learn that from??? Does the name "Ohio George" ring a bell????
Don't want to start a fight here, I'm trying to understand. Why so much compression? Isn't that getting into alcohol range? I mean, the big motors start somwhere around 500 pounds of torque, what does such extreme compression get? Teach me.
It depends on what your goal is. When I built those motors (late 80's) I did the best using off the shelf parts to go as quick as I needed for what class I was trying to run Now it's 20 years later, and with technology that much greater, You can buy out of the box stuff thats better than what I had back then. But the the theory still applies. get an Idea on how fast you want to go, and how much the car weighs and you see how much $$ it takes to go that fast. As Squirrel mentioned above, wanna run 87 octane motor, 9.5-10.1 compression... The off the shelf GM parts will work... I ran Alky because it is cheaper than gas per Drum...
Thank Guys I've been thinking it over and have decided to take advantage of what is good about the situation - a great running shortblock. I now plan on using the existing flat top pistons, going with a better pair of heads,and a hydralic cam that is a bit radical. My first thought with the flat tops is to go with a set of closed chamber oval ports. Does anyone have a good casting number suggestion? (I now have peanut ports) As far as a cam choice, any suggestions? I'm going to clean up the shortblock internally using kerosene, gunk the exterior, and paint her up. New timing chain set and hi volume oil pump. Add cam, lifters, heads, aluminum intake and carb - this is going to be a LOT cheaper than I had planned! Now to find a 4 bolt std bore block with a forged crank to build my monster..... As to why I want a hi compression big block - I raced a 1957 2door post in the 1970s with the exact engine that I am looking to re-create (except it was a 427) - if you have ever driven one, you wouldn't have to ask Thanks guys! Wildman1
Interesting thing about the closed chamber/open chamber heads...you probably won't see any performance difference, the added airflow of the open chamber seems to make up for the reduced compression? most of the early heads are pretty beat up by now, and need a lot of machine work.... A hydraulic flat tappet cam with about .550 lift and about 230 degrees at .050 will run nice up to about 5500 rpm, but don't expect it to live very long with todays materials/oils/whatever. I finally put a similar hydraulic roller in my blower motor, kind of pricy but I guess it's worth it.
Spoons - What casting number heads did you use? Did you add the oversize valves to the oval ports too? Thanks!
Yes I did on the oval ports. It ran just as good with them on the Injector (which was sq. port) as the sq. port L-88's..... Not sure of the casting #'s on the alum. heads... Best book to look at is "How to Hot Rod BBC's" It's a little old, but gives you an Idea on what was done with what they had...
The engine in the greaseslapper is a '79 3/4 ton truck 454, all std. flat top stock pistons. I've been told 8 1/2 :1 compression, I don't know. 280 deg. Crower hyd. cam. The guy that built it for me said it will sound serious with that much overlap, and run on 87. I haven't fired it yet, but Rick's comment was I was probably looking at 375-400 on pump gas. I figured with as much torque as I have on tap stock, I'm good to go. That's why I asked the question I did. The most engine I've been around was an 11:1 small block 350 with a 292 degree Crower in it, and it needed at least 102 just to run.
Mike .... The idea is to get as big as you can without costing you a fortune using off the shelf parts ( from GM, NAPA). and making her live... Big motors, how big you talkin??
This is the cam your'e talking about..?? POWER BEAST / Performance Level 3 - Delivers impressive mid-range and top-end power. Healthy sound. Economical price. RPM Power Range: 2000 to 4800 / Redline: 6200 plus.
I was wrong. What I have is Crower, grind #292 H. intake-292 deg,.502 lift, exhaust-302 deg,.527 lift. Everything else in the valvetrain is stock. A torker manifold on top, and a 625 cfm. Carter, which Carter says is sufficent !?! Like I said, I havn't fired this combination yet, but the guy that built it is one of the much used big block guys in the area. I've been told that with the little afb on top, I get back some of the torque I'm giving up with the cam. I don't even play an engine builder on TV, so you guys are more about this than I am. All I know is that everyone tells me to hold on to that 454 whatever. I probably won't get another one. Look at it this way, not much more weight than a mouse, MAJOR torque, and really impressive looking!! Gottaloveit!!!
The Jalopy Journal
