1.94 intake. 1.5 exhaust

I appreciate all the help! Just trying to learn as much as I can!

Ok not that I'm rooting for a cam yet. But to help me understand it better, besides the lift, what about the Howard's cam would work better with my build than let's say the 282s?

 

Ok lets go back in time to a hot cam that chevy put in the 327/365 hp 327/375 hp corvette and the 302/ 290 hp camaro Z/28. It was single pattern, .050 254/254 dur. Lift was .485/485. It had a mild spring pressure single spring around 300 open pressure and very little overall rate. How did chevy get away with so little spring pressure and warranty the cars engine and it lasted with such a high duration cam. The opening rate on the cam was extremely slow, lift was mild for such high duration in what were tiny 302/327 size engine and the heads were pretty much done in there airflow by .500 lift even there over the counter race cams barely had over .500 lift. Along comes harvey crane of crane cams in the 70s he figured out through common sense that street cars stuck with lousy exhaust systems at that time period along with lousy exhaust ports in a lot of heads. He started using a different exhaust lobe using more duration on it to hold the small exhaust valve open longer generally around 10 degrees more. This became known as the split cam, different intake and exhaust lobes. 1980s cam companies started increasing howinn quick the intake valves open this gave them more area under the curve, spring pressures had to go up some. Anytime on a flat tappet cam the spring pressure increased or the rocker ratio increased it puts more pressure on the lifters and cam lobe, more risk involved now but has to be done. Now fast forward to comp extreme, lunati voodoo and others. Now for more area under the curve they have decided we will try to get as close to opening the valves as they can to almost mimick a roller cam thats made out of steel. So now the spring rates increased again mostly more overall spring rate, but the grade of iron has not improved since the fifties and 60s. Unless you step up in cost to the pro 55 higher grade iron. So if you want best power in your cam regardless of rpm range you want you use the latest fast rate opening cams. If you do that on old core stuff you take higher risk of cam failure and no doubt no matter what cam is not going to last as long. There is no free lunch. As i said to you on the crower i would not do a modern cam today without the pro 55 cam core and baring that i may **** people off ill say it like it is. Only a fool would not spend another $100.00 for the better cam core. You want best power with more peace of mind you do the fast rate crower and its better cam core. You still want the power with fast rate cam willing to take risks at las vegas the howards , comp extreme, lunati voodoo cam's. can you get pro 55 core other companies, certainly. You want less power and cheaper cost and have more dependability with older tech comp magnum you can do that. But i cant read your mind you willing to spend extra get the best of both worlds or do you prefer to do cheap less power comp magnum. Other cam companies have the older designs like the comp magnum and newer fast rate cams. None of them really have any advantage in what they know to do over there competitors. Ill only repeat that fast rate higher spring pressures needed then desire to change to higher rocker ratio and doing that on cam core no better then 50s stuff, not a good risk.

 

While up middle of night. Chevy built the vortec head for a 350 chevy pickup ran around at 90 percent of the time at low rpms. So they used small intake valve and runners so the head would have high air velocity in something most of the time not reved over 3500 rpm. No bigger runners or valves needed for that. For performance use BBC has always been under valved for its size compared to the small block chevy big reason sbc makes better power per cube, but then they have so much more cubes they end up with more hp. Think about it a 302/327/350 with the standard 2.02 valve very good valve area. Now step up to the old 454 cu. Valve only 2.19 pitifull. Now today with bigger sbc being built 383 to 434 in size now there stuck generally in standard 23 degree heads to 2.10 to 2.12 valve size. Now those engines are worse off then the old 427454s were. Tighter lsa with more overlap can help under valved problem's. Like i said the 265 /283 cu. Used a 1.72 intake valve, you have 100 more cubic inches and barely much bigger intake valve area to feed it. Then you have more air strangling with the performer intake. The 750 carb perfect for your rpm goal.

 

Duration on a cam ot operating in rpm range you want worlds most important, lift is a friend for extra torgue. LSA just a little like tailoring a suit, oval track cams come with tighter LSA makes the cam pull a little earlier and stronger for them coming off the turn. Drag race cars with autos generally go for a tighter LSA. Duration huge killer to low rpm engine idle vacuum. tight LSA also hurts it. That said you are going to use modest duration cam so the tight LSA will not hurt. Not nearly important it will give a bit more of that rump, rump idle you still want. Will also crutch that to small intake valve you have with a tad more overlap without to high duration for your RPM range goal.

 

Wow so much info thanks!

So that Crower 00305 cam I take it you would highly reccomend. Granted I change the intake and stall. Should be everything I want

 

i personally like the howards specs better then the crower for what your going to do. That said i would not buy the howards cam and put it in my car if i had to use the cam core its on. One big reason the pro 55 cam core is out there for use, racers that are stuck with rules that only flat tappet cam can be used yet they need a radical high rpm cam with a lot of lift and duration. The pro 55 cam core is doing 450 lbs open in long races for long time periods without being replaced , have been told drag racers have done 525 lbs open, if you even tried that on, to use an example a milder ramp comp or any other brand the cam and lifters would gone almost instantly. That said its hard to come up with as mild a cam as you want off the shelf in a pro 55 core. Isky, comp, crower for sure do those cam cores. If you want to have them make you a cam and you decide comp cams, do not let them talk you into a bandiaded nitrided cam. If could not get the howards spec cam on 55 cam core i would do the crower. The older design magnum is not going to give the the same power as later fast ramp cams.

 

The 450lb spring pressure the use quality iron lifters on the 55 core. The 525 lb stuff they buy uncoated tool steel lifters generaly from trend at $300.00 for the lifters. Then cam companies will make you a tool steel flat tappet cam, for that you have to run the coated lifters they are around $1600.00 a set, probably about that much for a tool steel cam core. Dang if i were rich think i might try for rpm record of solid flat tappet. The nascar cup guys were doing 8900 down the straits during race and there qualifying engines 9300 rpm. With a flat tappet. So my 8 grand stuff of 1970s was sissy ****. Lol

 

Any thoughts on this cam?

https://www.herbertcams.com/245-250-...6lc-2500-7000/

 

I think both the howards and herbert cams at mid 240s .050 are really pushing out of your rpm range goals. The crower at 240 more like it. Heres the deal roller cams used to have as just 1 advantage a little wider power range 4000 rpm to 3500 for flat tappet cam. Well latest fast ramp cams have narrowed that gap closer to 4000. But 2500 to 7000 advertising hype. Depending on size engine how good the heads and intake are i can see that cam good to 7 k. I dont buy the part it pulls hard at 2500 rpm. You need strong low to mid ranged power with some left at higher revs. Its a street engine its not going to be at higher rpms all the time like oval track, road race and drag racing.spend the 100 bucks do the crower should make you happy. Back off going out to dinner 1 or two times. Thats just going in one end then out other in very short time lol. the 100 extra is long term worth it. Dont spend for new rpm manifold there for sale everwhere for less then half new cost. Manifolds dont wear out. If the cam or lifters fail let us know how saving 100 compares to the engine rebuild cost !!!

 

They claim for every 10 degrees added to INT. duration your moving the cam operating range up 500 rpm in a 350. So if you had a cam starting to pull good at say 3 grand add 10 more degrees you will be waiting to 3500 rpm for it to come on the cam.

 

Good way to compare two cams showing same .050 intake duration is look at the .200 valve lift point, 1 with higher duration number at that point most likely more power. Both crower 220 series and 290 series have good .200 numbers for a flat tappet cam, both series are on PRO 55 cam core. 00305 cam is a 290 series crower solid flat tappet.

 

Chevy 1970s cam out with 1.250 size aluminum retainers sold over the counter for sbc. Needless to say bad plan did not work, no i did not buy any lol.

 

Lets see L/48 cam 190 at .050 on intake. 350/350 hp cam 222. at 050. l /82 cam 224 at .050. Crower 00305. 240 at .050. 50 degrees more then L /48 cam so it pulls at say 2500 rpm later. Say 900 rpm roughly later then 224 / L/82 cam.

 

Had a new 78 L /82 ordered the car. Had 2.43 low gear M21 rear ratio was 3.70. 1979 ordered new Z/28 or as i like to call it stripes only Z/ 28. 264 low gear muncie, 3.70 rear ratio. 78 had the new vette and a new 3/4 ton chevy 454 truck. Truck only new thing i did not order other then motorcycles. Have fun don all the damage or help i can.