mseven

I am currently building a 396sbc. that will be street driven on pump gas. The lower end consists of 4 bolt (studded) 0 deck block, dished piston, Callie's crank, rods (all forged), 190afr comp. port heads (278@550 in 198 ex., 58 cc., 2.02/1.60 valves) will be looking at 10.50 cr.(roughly), long tubes, ported mini ram, 52 tb, 1.6 C.C.pro mags, 30#inj., 700r, trans-go, beast etc.etc., 2600 rpm conv. The current 3.07 gear will be swapped out to 4.10 using a 28"tire. I have good tuning skills, and car is MAP/SD strategy (727ecm).
I am looking for cam choices from those who have built 396's. I am looking at possibly using something in the range of 232/242 @50 duration on a 112-113 lsa.
My question is those who have done similar builds, what can I expect using this much duration including: vac. issues, drive-ability, idle, surging or any other lower rpm problems (off idle 1000-1100rpm) that cannot be "tuned out" including afr/02 changes, fueling, or? etc.etc.
TIA, Mick

Sonix

iTrader: (1)

What is the bore stroke combination you have to get 396 cubes? I've only seen one or two members on here with the oddball 350 super-stroke combos.
This is a stock block? Are you 100% certain you can get that much stroke out of it, without punching into water while clearancing? I was under the understanding it was difficult (ie. impossible) to have that much stroke in a stock block.

What RPM range are you hoping to achieve here?
With a big cube, long stroke, small bore engine like this, small heads (190cc on a ~400cube engine), it should tame the cam somewhat. I think your 232/242* idea is a good one actually. Should be a 2000-6000RPM type of setup i'd guess.

mseven

4.030 bore, 3.875, stroke 5.87 rod(actually should be 395.422 ci.)lol, 4 bolt gm block.
If using a gm block,when cubes get above 400+ ie. 409, 421 etc. would need the block being filled.
I want to be done around 6200-6400ish rpm

Sonix

iTrader: (1)

Custom rods?
That's not a common combo is it?
I thought much over the 3.75" stroke is dicey, in that you need to fill the block in case you hit water. Either way, if the block can do it, power to you. Out of curiosity, is it possible to get that many cubes relatively inexpensively, or are those high $$$ rods and crank?

I think you won't need that wide of an exhaust spread, due to the superior exhaust flow on those heads. The wide spread will help top end power though.

I'll be the first to admit i'm not experienced in your type of combo, so i'll wait for that one guy with a 395cid engine on these boards to chime in. However I think you will be very pleased with your combo, and I think that cam will work great for you.

mseven

at 396 it should be realatively normal, aside form me using the 5.875 rod(most use 6. the 5.875 allows for better piston/ring choice)and 18cc.dish piston as my heads are 58cc.

Air_Adam

396 isn't a common setup for a Gen 1 SBC, just because its so 'iffy' that it will actually work - no clearance problems or clearancing issues with the block/cam/rods. Its a much more finiky shortblock to build than a 383. Its much easier, and often cheaper, just to buy and rebuild a 400 sbc.

The 396ci combo is more popular with the LT1 crowd, as they don't have a 4.125" bore block to work with, so the 396ci setup is the biggest engine they can build with the Gen II blocks. Some of the 396ci LT1 engines are frighteningly fast, but how much gain over the same build with a 383ci crank/pistons? Probably not much.

//<86TA>\\

iTrader: (14)

im one of the oddball guys with a super stroke SBC

I have a 350, 4.030" bore 4" stroke yielding 408".
My cam is a compcams # CS XR288HR-10
gross lift with 1.5's .520 intake .540 exhaust
duration at .050 236 intake 242 exhaust
lobe separation 110.0

Im running 1.6 rockers, so ive got a bit more lift over the cams specs. Its a very good running motor, it has very good street manners and im quite happy with it. It produced 501 FWHP and 520 ft-lbs. Plenty of fun for the street, mild mannered until you stomp on it.

pandin

search on WASyl and Doc

WASyl ask a similar question only 383.

Doc has a 395

Hope this will help.

Orr89RocZ

iTrader: (20)

396 isnt gonna act too much different from a properly built 383. I'm doing a 383 and my custom cam should be done making power by 6200 i think. its a 230/245 with over .600 lift. somewhat similar to the cc306 but abit different valve timing events and more overlap.

IF i was building a miniram motor of that size and heads, i'd look for something similar to the LT1 grinds for those motors like Lloyd Elliots LE3 cam. Its a great custom grind for miniram/LT1 style intakes. You can find them used or new for sale on camaroz28.com sometimes. However its a tight lsa, about 107-109 but overlap isnt that bad since the duration doesnt have a big split, so its tuneable. its something like 234/238 but will vary as not all LE3 cams are the same but very close. lift is near .600 with 1.6 rockers. Makes power to 6200 or so in a 383/396. Should be looking at 430whp or so, depending

Bret Bauer is the guy taht grinds those cams for Lloyd Elliot. thats where i got my custom cam from. www.bauer-racing.com. Email him for a grind


ELSE there are some great off the shelf cams for that motor. The short runners like some overlap but aggressive lobes. Any of the XE grinds from comp like the 288HR which is a 236/242 would work well. the smaller 230/236 would probly peak at 5800 rpms in that car. 236/242 should peak by 6200 or so i'd say.

I've heard decent thigns about the big XFI grind, 242/248. it acts alittle smaller than it looks. Should peak by 6400 or so and hold power. I know one guy running it on a LT1 396 with good success. Will require great springs to control it over 6000 rpms. 113 lsa so its very easy on the ecm with some tuning. Alittle smaller would be a special order XFI 236/242. i'd be really tempted to try that grind on that motor. Comp doesnt offer it off the shelf but they do have the lobe profile and shouldnt charge much more if anything at all for the grind.

GM847 cam would rock in that motor too tho. CC306 would probly work just is a bit smaller and should peak by 5800-6000.

mseven

Thanks to all for the responses, it is appreciatted.

86 TA , at first thought that might be too large for my set-up, but the the more I think about it, the in. duration isn't much bigger than what I was alreay considering.

Pandin, I will do a search on those members.

Orr89RocZ,
yes I planned on treating it as lt1/4 style motor except w/out the pia distributer on those.
Looks like I am on the right track, I thought something in the range of 232-242 ish 112 lsa would be reasonable.
The 306 I know works, I thought that in todays age there would probably be better choices, and I thought I could probably go a tad bigger.
My only fear would be going to "edgy" (240+ in./ 248ish ex.)and not be that street friendly, and or, getting close to overcammed (236/242 sounds reasonable and I wouldn't really want to go any bigger).
Yeah, I still have to get a cam before I actually look at some springs, and do some mock up to see where I am at with the heads new cam combo. I'm not afraid to get good springs and already have ti. retainers, good locks et.all, need to see where the height etc. w/different springs and if I need additional maching of seats etc. I also felt I wanted to keep the promags (1.6's, 7/16 stud) for now as I wasn't looking to build a big rpm mill.
Bret Bauer is a good idea, I will email him and see what he would suggest based on my current set-up/parts. Thanks

Orr89RocZ

iTrader: (20)

Thing with Bret and most cam grinders is they wont give you specs until you buy the cam. Not a big deal as he will beable to make a cam for that motor. Just tell him your goals and he will create a cam profile for it. I'm eager to see what my cam does. It wasnt what i was expecting for the HSR manifold so i'm really interested in seeing how it works and what my rpm peak is.

i've heard vids of the big XFI grind compared to cc306 on 355 LT1's and its pretty tame for the specs, that 113 lsa helps. Doesnt sound much different from the cc306. I think it would work well in a 396. I think it will still create vacuum as it only has 70 degrees of overlap. cc306 has 74.5. my cam has 78 More is better for high rpms but will create less vacuum and low rpm power. I would not be too worried that cam would be too much for a 396 miniram car. But to play it safe i dont think you would go wrong with a 236/242 cam, either XE stuff or XFI stuff.

EVEN the TPIS ZZX cam, a 239/239 cam. Its pretty aggressive and will definately make big power up to 6400-6500 rpms on a 396.

Mac D

Camshaft: Hydraulic Roller Cam - .544 Intake / .555 Exhaust Lift and 230 Intake / 236 Exhaust Duration @ .050 - 110° LSA
This is what I have in my 396 Stroker Engine and it puts out 491 hp @509ft.bs of torque and is good up to 6200-6400 rpms

• Forged Crankshaft
• 3.875 " Stroke
• Forged I-beam 6.000" connecting rods
• Forged Pistons
• Internal Front/ External Rear
• Aluminum Cylinder Heads - HP8103
• 64cc chamber
• 2.08" intake/1.60" exhaust valves
• 220cc intake/67cc exhaust runners
• NEW Cast Iron Block
• Manufactured and Machined in the USA!
• Align honed main bearing bore
• Cylinders honed on computer-controlled machine to within .0002 straightness and roundness
• Cylinders are sonic tested for thickness
• 4-Bolt Main
• 4.000" Bore
• 1-Piece Rear Main Seal
• This is what I have in my 396 Sbc Stroker Engine