I am building a 400 small block for my 1985 camaro z28 with stock rods, crank, 2 bolt main caps, pistons. pistons are new but stock type. arp main cap studs and arp wave-loc rod bolts. comp magnum 292 hydraulic cam with double roller timing chain with arp cam bolts. a edelbrock performer rpm intake and a holley 650 double pumper carb with flowteck shorty camaro headers. I cant decide wich heads to use I want this motor to have aluminum heads and I want this motor to perform not have 15 mpg big valves are ok. help would be greatly apresheated also any ideas on hp figures for this motor would be great. also im only 17 this is my first motor build any other sugjestions would be great.  

that is a extremely healthy cam, and it wont make it very streetable, it will require a loose stall and low gears, look on the hot rod board for a example like yours, a man has a 402 BBC that is fouling plugs every 10-15 miles!!! it is a clutch car though but he has 3.42 gears and street miles are sending him to the poorhouse because of money into spark plugs, since you are running pump-gas you cant get compression high enough to allow this kinda of large duration camshaft and besides a cam of that duration will likely push a engine like that to 7000 RPM's, not the best for a street engine, and not the best for your low-buck rotating assembly, i would defitnely pick a little smaller cam, not unless you really want to treat this thing like a race car instead of a dual purpose car

about your decision on heads, its mainly the money you want to spend, vortec heads are cheap and dont work bad even on a 400 SBC, look at CHP's impersonator on their website, yet of course as for quarter mile times and upper RPM power a aftermarket head is better, AFR being what most magazines say is the best. But if you are really on a budget pick up a set of closed chamber early model SBC heads and port the hell out of them yourself and depending on how you study and how well you port you can have a very nice flowing port for little money

P.S. shorty headers are a far cry to what is actually needed, torque requires much longer tubes, so look into some better headers, just dont choose too large of pipes

I agree with gibbs . Even with 400 cubes to dampen the duration by compensating for the vacumme loss it is a way radical cam. Try one of the new extreme series cams by comp.cams.I have ben dyeing too whenever I get a life . 230 degrees of duration @.050 are about it . I mean if you want to drive where other traffic is and stoplights. One trip to a city  with the 292 and you wouls see. The other things you would need  for the 292 cam is a verry loose converter stall speed around 3500 rpm. And dont foreget the minimum of 410 gears if not 456. Now try to push that combo down the road at 60 mph while you worry about your oil temp  with the engine at a constant 3800 rpm. First time I drove a truck with 373s and a th 350 trans I had a line of cars passing me at 55 mph because I was afraid of the factory rod bolts and it felt like I was in first gear. I got uased to it but my cam was not a 292 so i still had some torque below 2200 rpm.  

well I do have a manual trans so the converter isent a problem and the car will only be driven a max of 3000 miles a year plus i also got the rohads lifters with varible duration so i will make less duration and more vacum at idle so it will be a little better i want to try the cam since i payed 100 bucks for it but if it realy becoms a problem i will switch it to a diffrent one. what i realy want to know is what heads i should use i already have the intake its a non vortec and im not switching to vortec. the car also has a 6 row oil cooler rated for up to 700hp plus the aluminum heads and intake and water pump should cool it just fine and with that big of motor even with that big of cam it should have enough power to push the 3300 pound camaro the weak 305 put the car in the high 13s at 102mph in the 1/4 mile  

im a strong believer against variable duration lifters, sure they reduce overlap and regain some dynamic compression at low engine speeds but you must realize that since the lifter bleeds down, aka collapses, at low speeds it suffers the same at high speeds and sacrifices top end valve control and reduces net lift, like i said that much duration on even that kind of engine is going to push it to high RPM's and the only real way to know what a valvetrain is doing @ that high of a RPM for somebody without a optron is to use a solid lifter, and since you are going to put 3000 miles on the car a year it sounds like no problem at all to use a solid, infact it will just help your quarter mile times i believe with the high peak HP RPM that engine will have especially if it has some good sized intake runners and plenum on it 

and if you are set on a hydraulic, and want to use rhoads, like David Vizard says, "if you have to use variable duration lifters you should've picked a smaller profile cam in the first place", also Mr. Vizard also states that since the variable duration lifter completely change low RPM valve timing that cam timing changes must be made to restore the original timing characteristics (aka since the rhoads cuts the duration short the engine actually thinks that the cam timing has been advanced several degrees, and needs retarding of the timing to restore the common 4 degrees advance needed, unless of course you have acess to a dyno and see a different cam timing as optimal for some reason)

well I wish I could have heard this from you earlyer. the person that did my machening to the block sugjested the roads lifters and the hydrolic cam. well if it realy gets to be a problem i will switch to a solid cam in the simular range. also what do you think about dart pro 1 aluminum heads with 1.08 1.625 valves with a 220 cc intake runner and 64cc chambers and 1.65 ratio harland sharp rockers and would my motor blow on a 150 hp shot of nos.

thanks for all the help

i kinda of see that as lesson, in my area I NEVER trust my machinist, in fact i try to minimize the work my machinist has to do on our engines greatly, not unless your seeing a very high end, high dollar known machinist in a large area i would back-up the info my machinist would give me

im sure that the setup wont give you any severe problems not unless you experience valve float and or are looking for better trap speeds/ET's, the rhoads should quiet down the cam enough to smooth out your idle and keep your vacuum up some

the dart heads are wonderful! it is well documented on dyno tests that they make great power, those heads will make some serious top end power on a large SBC, about the rockers you probably will not need the upped ratio, your cam is already large and the basis by which engines pick up power on ratio increases is if the engine is undercammed, i guess they might show a few ponies at the top end but not any large gains, and if your thinking in the street realm the .15 increase in rocker ratio will roughen a idle slightly, and increase valve guide wear slightly, and since your cam is already very big for the street id see how the setup handled street driving with stock ratio rockers first before taking that big of a jump, also i hope you realize that aluminum rockers have a fatigue life, in others words they will just eventually break, stainless steel rockers are the choice of the big dollar guys these days because they have a much better strength than aluminum rockers and i actually believe that since not as much metal is needed that stainless rockers are lighter than aluminum ones but dont hold me against that one

im sure with the proper pre-cautions a 150 shot could be done, but on your stock buttom end i would be scared and especially since im not much of a fan of nitrous anyway, people say its the cheapest power adder yet how cheap is having a little mistake or not having all the pre-cautions and paying for a new motor, but if you are serious on running a 150 on cast pistons, talk to techline coatings and ceramic coat the piston tops, cheap insurance

that is a good point about rockers what do you think of comp pro magnum 1.6 ratio and as to my bottom end how meany rpm would you run it it is stock aside from the polishing and hole smothing. but i did use the best 400 small block arp rod bolts and main studs. also should i use head studs or bolts with the dart pro 1 heads.  

AFR 195 is a good choice.

I strongly recommend NOT USING the stock 5.585" rods.

Use a 5.7" or 6" rod, and check for camshaft clearance. Also, a lighter piston (SRP, Ross) will help the whole lower end live longer, and rev quicker. I ran 11.60's in a camaro like yours with this combo. Be sure to use a 4000 or higher converter. I ran an 8" in my car, with no problem driving 90 miles round trip to the strip. A 750 carb would be better.

Be sure to use a 4000 or higher converter. I ran an 8" in my car, with no problem driving 90 miles round trip to the strip

May I ask how? did you have 5.86 gears and run a cruise speed of 4200 RPM's, or are you meaning 4000 flash stall?

3.90 gears in a 8.5" 10 bolt rear.

ATI 8" converter - the key to the 1.6 60 ft. times

Pump gas 406 w/ AFR heads and RPM intake

750 holley

Carter mech. fuel pump

2.5" exhaust

11.80 @114 with the full exhaust.

Comp 292 w/ 1.6 rockers (.533 net lift)

450 HP / 480 tq. on the dyno with Sunoco 94

3600 pound camaro (incl. driver)

tires would be equivalent to todays ET streets-fair weather only- 28" tall

Lots of fun on the street - drive it anywhere

The converter really isn't a big deal if you know how to drive it.

Your cam is way to big, 260 is about as big as you want to run on street application, 240 if it's an auto trans (you'll have to dump it in neutral every time you stop).  Port the stock heads yourself. Read up on this first, but it's not as hard as it sounds. What type of ignition system? What is your timing setting? Hope we didn't pound the cam thing to hard. Good luck!  

I run a stock GM dual plane aluminum intake, it works great. I can get you a part # if you need it. That cam will need a vacuum booster for your power brakes, be careful the first time you drive it you wom't have power brakes at lower RPM's without a booster.  

If you run nos in a motor like that you'll only do it once. ( O.K. maybe twice)