a little cam help please

[harshman]

I’m not an engine builder…. at all. I have a 396 bbc with the factory iron heads that came with the camaro. Currently it has a solid lifter cam in it and I want to switch to a hydraulic roller. I don’t know the comp. ratio but compression tests average 150 psi. I’ve been told that a 396 likes to rev faster and higher than most bbc but again, I have no idea. My question: will a hydraulic roller cam work for me or should I go with a regular hydraulic cam? I have a t56 trany and 4:10 gears. What cam grind would you recommend?

[zbugger]

That all really depends on what you want. Do you want a nice smooth idle? Or do you want to shake things up a bit? Is it just gonna be a cruiser? Is it gonna see track time? That's what's needed to get you the right info.

[Novacane]

The cranking compression is totally different then static compression. However at 150 PSI it doesn't sound as if the motor has very high compression ratio. Do you know what's in it for pistons or which heads are on it? If the static compression is indeed low (less then 10.5:1) you need to stick with camshafts that don't have a ton of duration @ .050". Too much duration with too little compression will make the motor VERY soggy. It is important to know some more info before properly selecting a camshaft. Items such as, compression ratio, intended rpm use, gears, auto/stick, intake manifold etc... The right cam can make all the difference in the world. Bigger isn't always better either!

A hydraulic roller will always make more power then a flat tappet style. Mainly because the ramps on the cam are more aggressive, allowing the valves to open fast, stay open longer and close real quick. Also the roller lifters reduce friction at the cam lobe/lifter location, freeing up some more HP!

[ProdigyCustoms]

There is a engine code stamped in the deck of the block, just at the front edge of the right head, it is a portion of the block that exteends past the head. The numbers will be something like T0304JD, then some more numbers like 9N501234. The first set of numbers I refered to, the T0304JD will tell me what motor you have to be sure it is indeed the original, and if not we can determine what you have. We can then learn compression and other critical info (assuming it is original and not molested yet).
I am assuming it is a 67 to 69 Camaro as they are the only to come with 396s, 70s to 73s were called 396, but were really 402s. 67 to 69 Camaro's came with 325HP and 350HP versions with oval port heads, steel intakes, Q Jet carbs, and hydraulic cams, and 375HP with aluminimum intake, Holley carb, and solid lifters. The 375HP also had much bigger rectangular port heads.
If it is the 063 oval ports, or similar, you will be HP limited by the heads. If it is 840 rectangular port heads, they will flow pretty well.
Also, we will need the information refered in the post above to better determine the correct cam.
I will say in advance I do not have a lot of personal experiance with hydraulic rollers. my lack of experiance comes from lack of satisfaction relayed by others that have used them. in fact as we speak i have 2 friends with float issues with hydraulic rollers. To me, they are a waste of money unless we use a real baby that can benifit from the ramp speed, otherwise, if you plan to turn it at all, i will say solids, or conventional hydraulic.

[harshman]

I checked the numbers and they aren't there. It extends out, but it looks as if it was machined flat. I do have the head numbers - 3904390 and there is also gm6t and conv4. I hope this helps. I’m pretty sure that the motor is not a stock 396. It also has a torker II and a 750 dbl pumper. The guy that I bought it from was a huge fan of engines and he said that he had it built by a friend but he can no longer get in contact with him. I hope this helps.
Obviously I intend to play with it as much as possible - on the track and off. Because of the t56 and the 4:10's, the low end I think is covered well. I’d like to see the band up a bit taking in consideration of the characteristics of a 396 bbc. As far as the idle, shakein' is a beautiful thing however, I’ll take a better performing engine over sound any day.

[ProdigyCustoms]

Is this a 67 Camaro? the heads are 67 only 396 / 325HP, which was a 10.25:1 motor. Lets check the casting number of the block. The casting number is a raised set of numbers cast into the block. They are located behind the left cyinder head on top of the left side bellhousing flange. Left being drivers side. We are looking for a 7 digit number similar to the head. If it is a 67 motor, it will end in 406 (in the industry we always refer to the last 3 numbers). This will tell me what year (s) it is, and possibile cubic inches. I say possibile cubic inches and year (s)because sometimes different CIs use the same blocks in different years, For example, 69 427s and 70 454 both used 512 casting blocks, so only the casting date can determine a 427 or 454. 69 Z28s, 302s (most 69 Z28s, that is) use 3970010 blocks, which were also used all through the 70s as 350s.
The casting date would be nice, but may be hard to see if it is a 67 motor. 1968 and earlier motors had the casting date under the number 4 cylinder on the side of the block, covered by the exhaust manifold when assembled, so you have to look from under the car.
1969 and later motors have the casting date on the bellhousing flange on the right center side, just behind the distributor. Both these numbers are a beotch to read in the car. If it is an old greasy motor, some brake clean will help.
The casting date will be something like B 24 7. In other words, letter (A - L), number (01 - 31), number (0 - 9).
Get me these numbers and we can get closer, but we still need Superman to see inside the motor and tell us if it has stock pistons, and how much the deck was cut when the numbers disappeared.

[zbugger]

As a beginner recommendation, I'd say take a look at the Retro-fit Extreme Energy Hydraulic Roller line. The cams I'd say to look at are between the XR-282 and the XR-288. They may overpower your heads, but I don't think so. There are decent odds that your heads have been worked a little. Your idle won't be smooth, but you should like the power. Remember, this is just a basic recommendation. I can't really say unless I knew a little more about your engine.

[harshman]

Well, I can feel the numbers on the driver's side rear but I can't see them. I’ve tried silly putty and plumber's putty to get impressions but to no avail. I’m gona be removing the brake booster - that might help me to see it better. There are no numbers on #4.

[ProdigyCustoms]

Don't do that. Get a drop light and look through the hood hinge. or crawl over the fender, or have a light girlfeind do it. no need to remove the booster, we do thhis all the time

[harshman]

two words...

hydro boost

[ballistic69]

Do you have enough room to get a small mirror back there to read the numbers?

[harshman]

i'll do a bit more checkin' tonight and reply with any numbers i find asap. BTW, how many numbers are in the seq.?

[harshman]

I got 'em

3969854

I looked up a chart on the web and it said a 402 or 454 with 360 to 375 hp in the year of 1972.

One concern, is this an internally balanced crank? The reason is when I swapped tranys form a th400 to a t56, I got a flywheel for an internally balanced crank. The flexplate from the old th400 was an internally balanced one.

[ProdigyCustoms]

It is a 1970 to 1972 402, not a 454. 454s in those years are 512 and 289 castings. Whatever book you looked at was wrong. If you get the casting date behind the distributor you will know what year it is. It could only be a 375 HP in 1970 as they made no 375 HPs in 71 or 72. A 375HP would be a 4 bolt. That can be determined by looking by the oil filter. Looking at the round oil filter receiver just above the filter. There are external oil adapters. The 4 bolt will have a large 3/4" plug instead of smaller 1/2" (1/2" or 3/8", can't remember) adapters. A 375HP would be a dome piston and would have come with rectangular ports, solids, aluminum intake, and Holley.
Now since 1970 402 / 375HPs were super rare (because of 454 / 450HPs available in Chevelles, and very few big block Camaros in 70 from a short model run), I am betting blind it was an oval port motor, which would have been 350HP or less depending on exactly what year and heads. With your heads, and stock oval port pistons, it would be a 10.5 to one or so, no more then 11:1 unless the heads or deck were whacked big time.
So we are getting closer anyway. Now if I could just remember the original question, LOL!

[ProdigyCustoms]

yeah, it is internal balance.

[harshman]

so it looks like it's a 402 w/ oval heads @ arround 350 hp with 10.5:1 cr. lets look at a hydraulic cam. any suggestions? i saw that edlbrock makes a torker II and a cam to match. would this be a good set up?

[ProdigyCustoms]

Funny you mention the Edelbrock stuff. About 7 years ago I did a matching pair, 70 Chevelle SS396, 4 speed car, and we used the torquer package on it, and then did a matching 70 SS396, 4 speed, Elcamino with the Performer package. It was a really cool set up, both cars were Black Cherry, black vinyl tops, black strips, black tonuao, The trilor for the Chevelle was Black Cherry with black SS stripes, SS wheels on everything. Looked damn cool pulling on the show field even though Elcaminos pull terrible.
Anyway, I like the Edelbrock set ups OK. They seemed well matched. Probably not ultimate HP for the combo, but no chance of mistake either.
I would suggest the RPM Air gap set up for you. If memory serves, the cam is in the mid 550 lift range and 240@50. It would pull nice to 6200 RPM. The RPM air gap would be the intake of choice and help some bottom end, but easily handle mid 6000 RPMs. A 830 Holley, some 1 3/4 hookers, an MSD, and a 3500 converter, and she will be a nice package you can drive anywhere, and bust some azz once in a while.

[harshman]

i thought that i would have hood clearance issues with the air gap which is why the torker II setup might be better. i also have a 750 dbl pumper and a t56 - not an automatic.

[ProdigyCustoms]

Had it backwards on the trans. In another post I talked about clearing an air gap under a flat SS hood. You can read and make a decision. However, with the lost bottom end from the torquer intake, your increased starting line ratio of the T56 over my presumed automatic will compensate for that. You may actually benefit from lost torque and be able to hook up better, unless you take pride in a car that won't hook up. There are those guy's that like to boost it is so powerful, it smokes the tires anytime you matt the pedal. I personally take pride in being able to hook in mud!
You can use that cam, or any dual pattern cam with similar specs, with either intake. However I would avoid a roller as they are prone to float over 6000. The 750 will be a bit small up top, but will work as long as it a double pumper.