EvilCartman

iTrader: (1)

I've got 6 grand into my new engine lol dunno what numbers it's running though yet. I'm guessing it's at least over 400 hp without much tuning so far.

zerotosixtyV8

lol, you've got more in your engine than I've got in my whole car and I'm hoping to get around 400. the only thing stock on the thing is the 350 bottom end though!

StealthElephant

Hey, looks like I got some feedback.

I'm really iffy on the cylinder heads. I know that CFM isn't always the most important thing. But how can you really find a good set of heads? I mean, what CFM does it take to support 450-500HP? At what lift levels does the flow have to be? Assuming the roller cam has around .560 lift and the duration is right. What port size is best? AFR are pretty well liked, but I've heard that the 260CFM @.5 lift is not always true on the 195s, that they are more like 240-245CFM. How important is the port size? I would think 195s is where I would like to be.

The cost isn't TOO bad, but if they dont' really flow 260CFM then will I have trouble hitting the 500 mark. The CNC full porting really jumps the price of the 195s, and getting the 210/220 race heads is more cost efficient to get the 260-275CFM. But when does intake port size affect streetability? How important are gross CFM numbers compared to port velocity/swirl/ etc etc?

My main concern is the intake setup. Will an LT1 intake even support 500HP? Assembly of an engine is cake, I can pick and chose my rotating assembly and such w/o much reguard except for cost and strength. The intake is what worries me, having a rock solid bottem end and the compression and cam to make 500HP, but not the intake setup to support it.

LilJayV10

iTrader: (5)

The best way to go about it IMO is find a shop that does it professionally and ask them. If you are planning on a LT1 buildup, heck even if its just a SBC. I'd talk to the guys at www.totalengineairflow.com, these guys are really smart. I am doing a engine buildup for my friends 93Z and he is getting his heads/cam from there. Yes max CFM doesn't mean max HP, port velocity, under the curve and mid lift numbers are just as important if not more so in making the type of power you want. It is essential that the parts are matched almost perfectly. Pick a set of cylinder heads first, then the cam after that so you can fill the cylinders efficently and make the most power, then things like stall, gears, intake and exhaust should come after that. this is just my opinion on how to do it. Thats one of the reasons I might pull my heads off this winter and have them flowed and may get a different cam. Hope this helps some.
Jason

dennis6

Daz, what are the cons of a BBC as for as fitment? I was steered away from it because of all the clearance issues. What fits and what don't? Any exhaust that fits without modification and major loss of ground clearance? Thanks!

zerotosixtyV8

there are people pushing 1000 HP through an LT1 intake and with 350 displacement. they are big turbo cars but still...

EvilCartman

iTrader: (1)

Hehe, I didn't want to really skimp on parts and just about everything was new. The block, timing cover, oilpan and main caps were the only things not new. Heck I got 2300 bucks in my transmission swap, transmission and converter were 1500 bucks lol. (actually there's another $700 to be added in there for a junk TH400 that got replaced) I don't mind the cost, just takes a little longer to get things

jrg77

So you can make 500 HP with a 406 "350" on 11:1 compression and solid lifters. It won't pass emissions and won't stop, steer, or keep the interior of the car cool. Doesn't that make it essentially a race motor?

The other choice is a big block that may pass emissions, still won't stop, steer, or cool the interior, and may be hard to fit into the engine compartment.

It seems much simpler to make a 406 "350" on 8.75:1 fuel injected (my choice SuperRam) compression and do the ATI thing. You have an engine designed to fit, has room for the accesories, and 500 HP, and with some dyno time will pass emissions too. You get everything!

Make mine to go with a G-force T56 please.

P.S. How much does this cost anyway?

zerotosixtyV8

lol, a 406 SBC is very easy to have pass emissions, all you'd need is EFI and two cat converters. It'll stop fine with the right cam. you can go wild and get a vacuum canister if you want. and power steering can be kept on the car, it's not effected by engine vacuum, and you can keep AC on an SBC anytime you want. not to mention its stock looking in appearance to testers, its a much easier fit that doesn't add weight up front. a BBC will never pass emissions in a 3rd gen, you will have trouble putting powersteering on as well as AC, the engine bay will be hotter, EFI systems are incredibly expensive for BBCs so no fuel economy, and you're handling will suffer. only reason to put a BBC in a 3rd gen would be if you are going all out drag and want the largest motor you can stuff into the car with over 1000 HP.

zerotosixtyV8

ah, you didn't tell me you put that money in the tranny. lol. I've got more money in my tranny than in my motor. $525 vigilante and $1000 built th700r4!

jrg77

Forgive my ignorance here... what's a 406? I assume its a bored and stroked 350. I was under the impression that 383 was as high as you could go.

EvilCartman

iTrader: (1)

The 6k into the engine itself still stands lol I bought around 4500 dollars worth of parts, dropped it off at the engine shop and spent another 1575 there. That was for more parts, machine work and assembly cost.
Before that, I swapped over to a TH400 last year. Bought a 100 dollar TH400 core, had it rebuilt and got the swap over crossmember and torque arm from Spohn. That transmission took a dump earlier this year so I bought a really good one for 1500 bucks with a converter. Converter alone would have cost me 800 to 900 bucks new and the transmission around 3800 bucks. It's good to know racers that have fire sales The new tranny will hold up to about 1,400 hp

zerotosixtyV8

406 = 400 block bored .030" over.
400 blocks have some amazingly high HP builds in them. 377, 406, 410, 415, 427, 434 can all make well over 500 HP and an equal amount of torque with the right combinations and maintain streetability well. they have a .125" bigger bore than a 350 block

lol that is nuts cartman, I wish I had that kinda cash! btw, where did you find a th400 core for $100??? what kind of converter are you running? I got my vigilante NIB from a friend for $525. Getting an HSR as an xmas gift from myself for myself rofl. should be seeing 330+ and low12-high11s on the motor with tuning!

EvilCartman

iTrader: (1)

Hehe, nothing like buying gifts for yourself at x-mas. I've run out of money after doing the engine

I got the core from a friend of mine who changed his mind and went to a powerglide. He got it from the transmission shop where I had it rebuilt. Damn thing burnt up 3 times with less than a year's ammount of driving on it (behind a 305!). That's when I got the good transmission. The converter is a 9" Continental and the transmission was built by Mikes Transmission.

Daz

iTrader: (1)

You will need an aftermarket electric fan if you want A/C for fitment and and cooking issues because of the condenser being in the way.The hooker 2" headers fit(note not the smaller 1 7/8)hits a small part in the control arm.This part is looks like an ear and it doesnt affect strength at all.The other is the weld at the bottom of the firewall.Best way is to cut and replace it with a plate.I just banged mine flat.My 3.5" collector flange sits very low but this is because Im using 3/4 coil cut stock 87 IROC springs with 255/40/17 front tires.It doesnt hit anything though.A future fix would be converting it to a slip on.The car handles great even on agressive street driving.BTW the headers doesnt need to be dented if you follow what I described
Daz

DeathStarr89

iTrader: (1)

I'm hittin close to the 400 mark with old school bolt on's. After i swap my cam, redo my exhaust and swap out the intake manifold for a Performer RPM i'm expecting 430-450. I'm running consistant high 12's/low 13's on a shi**y tranny. can't wait to get it all rebuilt....again.....for the 4th time....

pskel350

i dyno'ed at 296 rwhp with an Advanced autoparts shortblock. it isnt hard to get to 300 rwhp for pretty cheap, but after that, the $$$ really starts to add up.

especially trying to build a 500+ hp 383

LilJayV10

iTrader: (5)

Car craft did it with the 383 crate motor with vortec heads and a 282 or 288 xtreme roller. It never ceases to amaze me the power vortec heads will make.

zerotosixtyV8

and the poorest flowing of late model design aftermarket heads (Torquers) flow slightly better as cast still, impressive for a factory head, although quite outshined by the LS1/LS6 head.

scottland

they flow about 3cfm better on the exhaust side, and can't touch the vortecs on the intake side.
Vortec W/P torquer
.400 227 205
.500 239 221
.600 229 225

plus the torquer has bigger vavles. with the money you save buying vortecs over w/p heads, add 2.02"/1.60" vavles, then throw them on the flow bench, and see which head wins.

vortecs $480 for a pair; world/products are $760 for a pair.

for a budget head straight out of the box, vortecs CAN'T be beat. and if you talk about modified. vortecs with some bowl blending, and some work on the exhaust port, and 2.02"/1.60" vavles, are very hard to beat.

pskel350

vortec heads do produce a lot of power. they amaze me too.

however for my 383, i have decided on AFR heads and a XR288 cam. i think 500 hp is possible with that combo also

a 500 hp engine is not cheap, even with vortec heads, no matter how you look at it, plus you have to build the rest of the car to handle the power.

DeathStarr89

iTrader: (1)

sweet, i might have to swap out my 492's for some P&P'd Vortecs. that's a good price. anybody know if they are any better than 492 castings ? i found these in a junk yard in the back of an old chevy van under a bunch of trash. i ran the numbers and about crapped myself

TRAXION

I'm late posting to this topic but just thought I would share. 500hp isn't really that difficult to do NA through a 350. I'm pushing about that much (at the crank) on my stock L98 shortblock. You need halfway decent heads (mine flow about ~275cfm @ 0.600) and a good flowing cam (230+ duration). Obviously, an intake like the MiniRam is needed. Couple that with a great exhaust, stable valvetrain, and a great tune and it is extremely possible.

If you step up to a 400 block then it's going to get even easier to push about 500hp.

Tim