I am looking at boosting my 1976 455 "483 cid" I was wondering what you guys think for cams. I have a 800 cfm carb w/ a performer intake. 100% rebuilt in may just got 1000 miles on it. I have low compression 7.25-1.
this is my first forum ever being on. Barry

 

Well how 'bout that.

Welcome aboard

I'll let the engine gurus chime in to help ya with your build

 

I love your hood scoops

 

With you that low compression there not much you can do should have least gone 9.6-1 Really now your just stuck. Any thing you do is not going to make much power. Unless you change your pistons. With that low of compression all need is a 650cfm carb. Stock cam is big enough.

 

So right now your running a basic 1976 type 455 with low compression pistons (lower then normal)

To get to 483 cubic your talking about a "stroker Kit" which means a new crank, Rods. Pistons, lots of head work to make the motor breath, different intake and different carb, headers. Then there is building a transmission, driveshaft & rearend to handle it all. Not to mention electric fuel pump and ignition system upgrades and on and on....... Are you sure you want to take this on, we are talking big bucks and I did not even mention the machine work required.

Low buck way to up HP is higher compression pistions 9:5.1 and a little head work along with free flowing exhaust

What are you trying to get to,

1. all out drag race car
2. Street / strip car
3. Performance daily driver

Think about it then ask some more questions

 

Welcome to CO. Looking forward to helping you out.

 

well I am adding a Turbo or supercharger to this pumping 8-16 psig giving me more a long the compression you were talking right? this is basically a stocker that has been bored over. I did look in to my cid, wright now I am closer to a 461 than 483. I was given the wrong numbers. sorry

 

Yes, a 455 bored .030 over is a 461. If you have low compression pistons you might have a good basis for a super/turbo charged engine; however, you will have to make sure your heads and cam are appropriate for boost. If you have a basically stock 76 455 then you are running J heads which are the worst BBO heads available. I don't know much about running a super/turbo charger but I guarantee you that you wouldn't want to run J heads on an engine with boost.

 

I suggest you talk to the machine shop where you had the engine rebuilt about you plans and get there advice. With that much boost you will need a strong bottom end larger oil pan high volumn oil pump, etc.

 

Before you rebuild a motor you know what your going want out of it. Then build it to the way you want it. It's Citcapp what are go to do with it. If you looking for performance you should have built it that way. A turbo or supercharge will not work that motor the way it is built. You will have pull it apart change the pistons, cam, rods, do a lot of head work. You"ll have to send a lot of money it. Should have built right the first time because a good running 455 is hard to beat. You don't need turbo or whatever. You need higher compression piston. A little head work. That will make a big difference.

 

Like Pat mentioned you will definitely need a HV oil pump and deep sump pan. Depending on how much boost you want to run will determine if you need to change the bottom end.

 

I don't know much about about turbo chargers and superchargers but I thought when you built a Turbo or supercharged engine you need to go with a lower compression? I know that your saying he doesn't need a turbo but if he wanted one didn't he do the right thing by lowering his compression?

Like I said tho I don't know much about turbos or anything performance so I could be totally wrong here.

 

I have a set of complete F heads sitting here if there better for your build than J heads.

 

Yes you need a low compression motor, but stock parts will not well with superchargers or turbos. If you use a cast piston you'll end with a hole in the top of your piston. Stock rods could brake under lot of boost need I beams. Stock cam would be all wrong. A lot times you run your timming retarted.

 

I disagree. Oldsmobile used a turbocharger in the Starfire with the 215.

I would be hesitant to say that stock Oldsmobile rods wouldn't be strong enough. I've never heard of anyone but serious racers using aftermarket rods. I believe they are the strongest piece of the bottom end.

It will all depend on how much boost the engine runs.

 

My heads are g's on a f block.
I traded a snow blower for the 455 and th 350. Only had 600 miles on motor and 300 on trans. Has new rods pistons cam intake carb. the rebuild was done in 1994 and has been siting on a skid. so i pulled it apart to inspect it. Everything miked out. I put new bearing and gaskets and put her in a 1985 delta 88... I love it! never want to go back to a chevy 350 cid!!!

 

[quote=455islove;113356]I am looking at boosting my 1976 455 "483 cid" I was wondering what you guys think for cams.

as to my first question what kind of cam. I asked napa they have no thoughts. and said after calling that I was going to have to buy a cam and then have it milled.

 

Their are several off the shelf cams available for you engine but you need a plan to make everything match upp for the best performance. So start the research. Look on the big block site there are several engine builds to give you some ideas to start you plan

 

Having built many turbocharged engines & can tell you on of the best things with forced induction engines is the head & ports don't play nearly as key a roll as they do in naturally asperated engines. Don't forget port size & shaped don't matter because you are forcing the air in & not relying on the port to help with the flow. As far as the camshaft goes you want a camshaft with as much lift and as little overlap as possible. Overlap is actually a bad thing on a boosted engine as you will actually be forcing air & fuel through the cylinder into the exhaust wasting potential boost & air/fuel mixture. It won't be an easy thing to find on something like an oldsmobile I am guessing as most cams are designed for naturally aspirated applications. There may be cams for superchargers which would work OK but not be ideal because turbochargers don't produce boost until higher RPMs that supers.

 

I bought some stuff from Lynn at Mondello the other day, when ordering cam he did say they have one for turbo street application.....Blowers, turbos, super chargers like lower compression motors and the good thing is that you can under-drive, overdrive or adjust boost to the type of performance you require. Bad thing is too much of either on stock parts will send stuff flying every where.

 

You can use a small turbo with the stock motor. A turbo that adds like 25 hp. That is a wast of time. Since you have lower compression motor. You could made more power with different pistons bottom line.

 

This is what it boils down to. Unless you are willing to spend big bucks on setting up an engine with a turbo or super charger you would be better off keeping your Olds engine mostly stock, or adding a few aftermarket parts.

 

My last comment on this. Seeing as how this engine is fresh, drive it as is and look for another 455 that you can build over time and build it from the ground up for power this way you can spread the cost over a several months. Then when your done change out the engine and either sell the low compression one or keep it for a backup. Serveral of us here like having a backup enginen, I know I do.

 

thanks for all of your help
is there in differences in a scat Pontiac crank and olds crank? looking at part # 4-400p-4500-6700-2200-3. mite of found a new block.

 

I looked it up to make sure but they have different casting numbers so I would think they wouldn't interchange, but not 100% sure maybe 98% sure.

 

They do not interchange. Although Oldsmobile, Pontiac and Buick all have 455 engines they do not share the same architecture.