Thread: What can I expect? (New 454)

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Hello you all, I'm new to this site and before I ask my question I just want to say I think all of you are very knowledgable on your info and it is much appreciated for your advice. What I have is a .040 over fresh 454 (casting number 3963512) with flat top pistons, powermax cam .534 int, .553 exh, duration 286int/296exh . Closed chamber heads (casting numbers 3872702) I used felpro head gaskets .039 thick. Also I'm running roller tipped rockers, mallory ignition, holly med rise intake, edelbrock 750 cfm carburetor, full length headman headers. With what I listed above what can I expect in HP and torque, what kind of compression will I have with the 702 heads and flat top pistons. Lastly will my engine lope with the cam I listed above. Thank you very much......Also engine is still on the stand so if you all think I could improve on what I have your suggestions will be most welcomed.....Thanks again.

Det45....(Name?) Welcome to the site. What is the deck hgt on the block? That will affect your c/r quite a bit. Those heads, if they are not bowl blended and ported too much (in other words, if they are stock size chambers) are going to give you a pretty decent c/r. Chamber size should be a little less than 100cc's, maybe 98 or so. With flat tops ( are we talking stock flat tops, like a little dish in the center?) you still should be somewhere around 9.0 to 9.5/1. I would think HP might be around 400, and tq maybe a bit more, 450?? I'll run it thru DD later and see what comes up. What are the cam specs at .050? And what is the LSA....110 I assume? That should be a pretty good cam, Im not a big Crane fan, but they're pretty good. Post the rest of the numbers when you get a chance. What are you gonna use this for? Street mainly? What tranny and rear gears are you running? If auto, what stall? How big are the headers? (diam) Carb and intake are OK....Dont be swayed by 'bigger is better' in the carb area, this is plenty for your engine unless it's a race only, which is obviously isnt. Let us know more. Oh, and even though those heads are old design, (closed chamber), I have a friend who's running similar closed chambers, and he's in the 10's....WELL into the 10's. So they do work well. John

Wow! thank you for your reply Johnny! As far as I know the deck hight is stock and the pistons are flat top (no dish). I don't know the header diameter. I will be running a turbo 350 trans, 12 bolt rearend with 3:73s, half ton pickup (Texas Thing) Also I will be using a hugues 2500 stall convertor......

Figuring your c/r with the flat tops and 98cc chambers (if that's what they really are), and gasket of .039 with a standard deck of .025, your c/r says 9.14. I dont know if this engine is already built or not, but if you go with a steel shim head gasket, (.022) you bump up to just over 9.4 on your c/r. Im not sure that cam will work with that c/r, at least not effectively. Based on the adv. duration, it's pretty big for that c/r. I would check with the cam mfgr., tell them what you have, and see what they say. I would think 10/1 or better. Also, the converter at 2500? Im no expert on trannys, but something tells me it might be a little tight for that cam. I ran DD using 9/1 compression, and pretty much everything else as you gave it, and it shows 433 hp @ 5500, and 475 tq @ 4000. You still didnt say what you will be doing with this truck.

Thanks for the reply Johnny, your advice is valuable. I looked up the head castings 3872702 on mor-tec and found them to be a 1966 casting for a 396 and 427. They are closed chamber @ 98.4 cc and standard size valves and large oval ports. These heads are not modified and are basically original. I will be using the truck as a weekend street toy. The instructions that came with the cam stated using a 2500 stall. Engine is builtup and sitting in the engine stand. If my combo isn't right I won't hesitate to tear it down to make it right per you alls advice....

Well, dont change anything at all on MY advice!!! If it's already built, just run it!! If you have the cam card, what are the rest of the numbers? LSA and duration at .050 is what Im curious about. If it says a 2500 stall is good, then so be it. The head numbers in Mortec are just a guide, dont forget that. Just because it says 98cc, dont bank on it. I have seen them be all over the place at times....but also they are right on the mark many times. That's why if I ever have a set of heads that Im going to use, I will always cc them, that way you know for sure. In your case, I would say just use the engine as is. You can always make changes later if there's something you just have to change. But I'll bet you'll like it fine as is. Any big block is tons of fun!! Keep us posted.

Here are the cam specs: Crane powermax cam part # 134241, (Duration @ .050 is 226int/236exh) Advertised duration is 286int/296exh Cam lift is, .534 int lift/.553exh lift. Lobe seperation is 112. I hope these numbers clear things up. Do you think this cam will lope at idle? ( I love hearing the cam at idle).......Thanks

It should sound pretty nice, although with a 112 LSA, it will have a smoother idle than some you hear....but I think it will sound good.

it will not have much lope but who cares? you will have enough TQ to pull a barn down with it?

Thank You for your advice you all. I will be a little nervous when I first start it up but then again I'm always nervous on first cranks......

Make sure it fires right away so you dont have to crank a lot and wipe off all the cam lube. Break-in is critical, maybe more so on a BBC. Are you using GM EOS in the oil? Cant hurt to do everything you can to minimize wear.

Thank you for your advice.... Johnny what is GM EOS oil? Also should I pre-lube the oil system using a modified old distributor and drill? Thanks brother, YOU'RE THE MAN!

One other thing I forgot to ask you all. My truck has been sitting in my garage for about six months with three quarters of a tank of gas. Will I have to drop the fuel tank and drain the fuel or will I be able to use the gas with the new engine.....Also how much trans oil do I put in my new 2500 stall convertor and transmission prior to installing the trans into the truck. (turbo 350 with standard pan) Thanks again.

EOS is engine oil supplement....use it every time you fire up a new engine. You have to get it from a GM dealer, they have it in stock. Yes, definitely pre-lube for several minutes with the drill and adapter. Then, cross your fingers and fire it up!! Keep the rpms up at 1500 to 2400 or so, varying it up and down several times. Are you doing this in the car, or is the engine on a stand? Make sure the cooling system is up to par...the engine will run hot, what with the higher rpms and not moving at all. I ususally put at least one box fan in front of the radiator, this helps. Watch the temp, if it creeps up too high, shut it down. They say 20 minutes for the break-in....I have seen everything from no break-in (my friend does this, and gets away with it...he buys the cheapest cams and parts, and never has a problem!!!) to 30 minutes or so. If you get a full 15 or 20 minutes, that should be fine. It doesnt have to be all at once either. If you have to shut down, it wont hurt anything. The gas question will likely bring lots of responses, but I can tell you that I have used gas that has been sitting in the tank for a few years, and it still starts and runs OK...I dont recommend doing it on a regular basis, but if it's in the tank now, I would definitely use it. Dont know how much capacity the tranny will be...but I'll see if I can find out. Good luck!!! John

First off the gas question ,It will take you 10 minutes,and 10 dollars to put fresh fuel in the system.Then you know you dont have to worry about that.Bad fuel,new engine ,not a good Idea.I would not do it.Also double check about the RPM's ,If I remember correctly the reason the engine needs to stay at 2200 rpm or a little more is because thats what it takes to keep the engine oil splashing inside the engine in all the right places.Its been a while since I have done this,but the crank does'nt splash oil up to the cam until a certain rpm.