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Best cam setup for this 454 big block

41K views 31 replies 12 participants last post by  kettbo 
#1 ·
Hello,

After a long vacation i went on with restoring my chevelle.

I have removed the engine from the car and i am looking for a good cam with distributor and ignition.

I have the following setup allready

The intake is a aluminium gm hi perf intake gm3933163 and the cylinder head is casting 6272990 with 118cc Replacement Rectangular port 325cc intake. I have 1 3/4 inch alu headers with a 3 inch collector and a holley 830cfm NASCAR carb.

So what cams will be best too use with this setup and what distributor and ignition do you recommend to me.

Thx for your help.
 
#4 ·
#3 ·
hydraulic or solid, flat tappet or roller?
 
#8 ·
How much rpm do you want out of the engine? Hyd roller or Solid roller? What rocker arm ratio is on the engine now?
Good question. I dont know that. The guy that built the car is in jail.

How can i find out if i have a Hyd roller or Solid roller and how can i find out what the rocker arm ratio is.

When the engine goes above 4500 rpm it is losing power. So i suggest that the cam i am using now is not for higher rpm's
 
#9 ·
You are going to have to get into the engine see what you have. The heads are quite large so the engine won't start feeling good until after 4000 rpm but it is a stick car. If you want a max of 6500 or so I would go hyd roller. If you want to rev the engine higher then that we need to go solid roller. I can supply you the whole kit for either. If you need an idea on pricing PM me. You can check my reputation on this board, its pretty good.
 
#10 ·
You are going to have to get into the engine see what you have. The heads are quite large so the engine won't start feeling good until after 4000 rpm but it is a stick car. If you want a max of 6500 or so I would go hyd roller. If you want to rev the engine higher then that we need to go solid roller. I can supply you the whole kit for either. If you need an idea on pricing PM me. You can check my reputation on this board, its pretty good.
What do you mean with " the engine won't start feeling good until after 4000 rpm but it is a stick car"

Do you mean that these heads are made for higher rpm? So the engine will produce some power when i go above the 4000 rpm?
 
#11 ·
The heads are quite large for that CID so the manual tranny will help with this. A small roller cam can be used to broaden out the powerband and give me more useable power but we have to know what is in the car now.
 
#12 ·
The heads are quite large for that CID so the manual tranny will help with this. A small roller cam can be used to broaden out the powerband and give me more useable power but we have to know what is in the car now.
Ok,

I have a th400 automatic and not a manual tranny.

But do you mean that these heads are made for the higher rpm range? When will these heads give their best performance? above or below 5500 rpm?

So to find out what i have now i have to open my 454 engine and find out.
 
#13 ·
Ok thought I saw manual. Heads are best suited with that kind of runner volume to make power starting above 4000 rpm. Need to know what you have on the inside of engine now so we would know what you need to accomplish your goals.
 
#14 ·
Ok thought I saw manual. Heads are best suited with that kind of runner volume to make power starting above 4000 rpm. Need to know what you have on the inside of engine now so we would know what you need to accomplish your goals.
Today i opened my engine and found out that i have Hydraulic Roller Tappet in the engine.

What else do you need to know to tell me what the best cam is for this setup.

I wanne start fresh and want to flow the 6272990 heads and put new valves in it.
 
#15 ·
Michel, I know you dont have access to a wide assortment of Chevy BB heads over there, but do flow the 990's. You may be somewhat disappointed in them, so the right cam will be critical. only experience with 990s on a 427, they were too big everywhere. ( so far the engine has made it best power with small, highly ported rectangulars so a rect head worked best, just not these unported ones.).

But you have 1/4" longer stroke to create more velocity.
 
#16 ·
Michel, I know you dont have access to a wide assortment of Chevy BB heads over there, but do flow the 990's. You may be somewhat disappointed in them, so the right cam will be critical. only experience with 990s on a 427, they were too big everywhere. ( so far the engine has made it best power with small, highly ported rectangulars so a rect head worked best, just not these unported ones.).

But you have 1/4" longer stroke to create more velocity.
Buying chevy heads overhere is a real dissaster. With the taxes and shipping cost the heads become twice as expensive.

If i take the heads off and take them to a good tuner to let him flow the heads will that make a difference?

What do you suggest?
 
#19 ·
Today i checked the compression ratio off my 454 engine with the midlock Te-115

The worst cylinder had a 12 compression.

The best cylinder had a 12.2 compression.

Is that any good or bad?
As far as spread that is very good

But this will not tell you your static compression ratio only cranking compression which is not the same thing

Static needs to be calculated & you need to know the bore, stroke, chamber size, dome size in cc, deck height (how far down the flat of the piston is in the bore) & gasket thickness & really should know how far down your top ring is but this is only a small amount
 
#22 ·
Should be roughly 10.0 depending on the height of the piston in the bore & the actual size of the chamber & what head gasket you have
 
#23 · (Edited)
Today i have removed the cilinderheads and i have a few questions.

Most valves have a brown colour. 2 valves have a different colour. One is black and one is like caramel. See pictures. Is that good or bad and what does that mean ???

I have also removed the rollers. Could somebody tell me what type off rollers i have. See pictures.

Thanx for all your help.







 
#24 ·
Looks a little rich

Those are flat tappet not hyd roller lifters
To go to a hyd roller you are going to need a cam, lifters, thrust button or a step nose cam & retaining plate with the correct timing set & different pushrods
 
#29 ·
It is hard to keep those cars running overhere but we do our best. Fuel prices are high 8,73 dollar per gallon. We also have environment rules in Europe in some big cities. Last time i went to Germany and got a fine because i was not allowed to drive in the city with my car.

But we love muscle cars 2 :thumbsup:
 
#30 ·
Hey; I might have the answer to your cam selection. After I restored my 1970 LS6 4 speed car I became quite disappointed with cams that were selected for me at my local speed shop. The cams never responsive enough for street use. So I did some studying and it seems that most of the cam grinders were just puting in just to much duration and to much lobe seperation. So I had a cam ground with these specs; 511 lift int. Duration 236. Exh.248. Duration. Lobe seperation 107. This cam has extreme acceleration for stop light to stop light use. I love it. Sounds great and has enough vacuum for power brakes.
 
#31 ·
Been to Holland many times (grand-baby lives over there :)). Seen quite a few muscle cars done very nicely. You'all have good resources like good Euro paints and such to do nice cars.

The thing I'd do is build a nice street motor that could do some duty on the drag strip a few weekends a year. Say 70% street and 30% strip.

The 990 heads have big runners so the mixture velocity is low at idle and around town speeds ( <3,500 say). That leads to fuel dropping out and other issues. But spinning a big motor at 3,500 rpm plus all the time will drink expensive Euro gas by the bucket - not good.

If you build the motor to match the heads it will be something like 6,500 redline and kind of limp at 2,500 where a lot of street use takes place. It will run, but not all that crisp and responsive around town. So you'll have to watch the traffic and the make sure you are building RPM so when that other car comes along side, you are well ready to leave :D

I hate to say this to you because of the costs involved, but I'd switch to smaller runner oval port aluminum heads and keep the cam and lifters you have if it proves to be decent one... That also means another intake manifold and the costs keep going up. Really sorry about that ... I'd be listing the 990's and the GM intake on Markplatz and in the racers forums. Someone will want them and pay well for them. Someone who wants 70% race and 30% street. You may even be able to swap for some nice 781's :)

Or, I'd work with Chris go get the best you can out of a street hyd-roll'er and those heads. It will be a compromise that might work OK, but ...

But I don't know where you live and what traffic conditions are like on most of your trips... I've been in some pretty long freeway line-ups getting into or around Rotterdam and such, it can be tough with a somewhat radical motor, rain soaked roads, and folks cutting in just when you get rolling ...

If most of your cursing to say the coast is at 3,000 RPM, that's where I'd focus the build. Make that the happy spot with max torque right around there, or slightly above. that way, if you want to pass a tractor hauling a trailer (they allow farm tractors on the highways in Holland), it's just a stab of the throttle away :)

It's all too easy to get dreamy eyed about building bad ass car and building in all sorts of big parts (heads and cams and carbs), when that is not what's needed. This is about building a package. That's why the folks are asking questions, they want more info about what you have now, how it works (or doesn't...) and where you want the build to go.

Stick around and keep the discussion going and we can get you a very decent build that will drive great. It just won't happen with one or two posts ...
 
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