383 stroker build help

[webbs7mgte]

got a sbc 350 form a 69-70 according to the casting numbers. im going to go 383 stroker for it and sell it. or toss it in like a mid 80's cutlass and than sell it lol. but is this the proper way to achieve a 383 stroker

-400 crank
-.030 over

any help greatly appreciated

 

[Slow66]

Yes, that combo will yield a 383. Depending on what kit you chose, you can go with either a 5.7" or 6" rod. The 6" rod will achieve a better rod:stroke ratio (1.6 vs 1.52). I would also use a flat top style piston with a smaller chamber head, to try and achieve around 10:1 to make some good power on pump fuel. A nice hydraulic roller cam would be nice if the budget allows too...

If you build a nice solid sbc, you may not want to sell it....

 

[Doward]

10-4 on that. Bryan's right - a healthy SBC is a hell of a lot of fun!

 

[webbs7mgte]

lol thanks to both of you but its just to get some profit to get a enw daily driver having no vehicle is no fun lol. Also heres my set up i plan on running. Please help me with what shoudl be changed. Im not good with old schools first one i am building here lol.

-scant brand enw 400 crank-$180
-76cc heads everything being rebuilt with comp cam springs and rocker arms and new cam
- federal mogual flat top pistons
-brass freeze plugs
-brand new 350 rods(dont know size yet will look)
-all cleviette bearings
-edlebrock intake mani
-holley 4 barrel 650 i think

any suggestions on what to change

all in all it is going to run me about $1500 boring and cleanign and all of that will be free as im attending school for automotive in january

 

[Doward]

Make sure the pistons are the correct compression height for the rods you have.

 

[webbs7mgte]

ok will do what kind of number can i expect on this type of motor?

 

[bmoss85]

you can buy a whole kit for around 1200 bucks. you cant use a stock 400 crank, the stroker crank will have the same amount of stroke as 400 but it has 350 journals. iirc, the journals on a 350 are .200" smaller. i built one for a guy a couple years ago. it was a 2 bolt 350, but i put in 4 bolt splayed caps. had to do a lot of grinding on the block to get clearance for the rods. i ground the block to .050" clearance between the rods and block.

 

[webbs7mgte]

where did you get the kit from.

 

[bmoss85]

he got it from summit. eagle has two dofferent kits, 1 kit has a cast crank and cheaper rods, and the other has froged crank and better rods. i cant remeber if the pistons were the same or not.

edit: heres a link to eagles kits http://store.summitracing.com/egnsearch.asp?N=700+400075+4294919598+4294908216+115+4294832650

 

[webbs7mgte]

with that kit will i sitll have to grind down the block or will that oen work or no?cus i have 3 350 blocks siting here and i plan to make a 383 stroker out of all of them and sell them off for like 2 grand lol

 

[bmoss85]

im pretty sure you're gonna have to grind on the block no matter what. you would be grinding at the bottom of the block so that when each piston is at bdc its not hitting the block. ive only done 1 383 motor and i had to do quite a bit if grinding to get .050" clearance between the block and rods. just use a die grinder and a good carbide bit. are you gonna put it together or have your machinist do it?

 

[Doward]

btw, when it comes to cams, I made great power with a small solid roller cam (224/224 @ .050, .545" lift) with a tight lsa of 108.

I noticed my 383 really liked a tight LSA. 106-108 seemed to be the sweet spot!

 

[webbs7mgte]

thanks i will deffinitly be using this thread over and over through this build and. ill be doing all the machine work im going to school for automotive engine machinists and assembler(sp?). Also im not big with old chevy motors if i am correct difference between hydrlic cam and roller cam is just the lifters correct? or is the a combo between the lifters and rocker arms

 

[Slow66]

There's basically 4 different types of cams for these motors. Hydraulic flat tappet, solid flat tappet, hydraulic roller, and solid roller. The main difference is the lifter style. Hydraulic lifters have a chamber for oil in them that takes up slack in the valvetrain (less noisy, no need for frequent adjustment) and solids are just that, solid, and need to be lashed at the rocker arm for clearances. Flat tappets are the standard style lifter that are flat on the bottom (much like the 7m valve shims) and ride on the cam. Lobe ramp aggressiveness and duration are limited by the nature of this lifter. Roller lifters have a roller trunnion at the bottom that "rolls" over the cam lobes. More aggressive ramps and duration can be achieved, and greater power, as well. Comes at a price though.

Hydraulics are better for street motors due to less upkeep, solids are better for more serious motors. Rollers will make more power, but come at a higher cost.

 

[Isphius]

Just an FYI, your not going to make much of a profit, and if you want to factor in the amount of time you could spend working instead of building/machining you will indeed lose money. But it will be a ton of fun and a great learning exp. But why chose a 383 stroker? You could spend your money on a the right parts and have a 450hp 350(78 hp/liter from a CARB!). And no major machine work required. But just a word of advice, power is in the HEADS! Dont skimp on heads, and make a good cam choice based on that. you can run some AFR 215s, a forged crank, good rods and pistons, a huge cam, and have a fire breathing 6500+ rpm 350. Or run 160cc vortecs, a big dual plane intake, a well chosen cam, and make a ton of torque with a 383 crank and have 450 ft lbs of torque. You can also go the other way...a 400 block with a 350 crank. 372 oversquare motor. But you have to use a chevy 400, not a pontiac 400. Do you already have a motor or any parts?

 

[webbs7mgte]

yes I got 2 free small block 350s one on the stand i got a set of heads free and a free stock intake mani and rodchester quadrajet 4barrel. i plan on using hte block and checking the crank for journals and see how they are(possibly ordering a new scat crank. im going to try and just rebuild hte heads with better springs retainers and valves and rockers. have been looking into just buying some already assembled heads. but i was going to go edelbrock intake and a hollley 650 or 750 4 barrel. i could assemble a full motor on the parts i have but i want to make some profit. would i be best off just cleaning everything up getting a better intake mani and heads and better carb clean and polish everything to death(everything that can be polished) and than just sell it

 

[Isphius]

if you want to make money just assemble a running motor and try to sell it with whatever parts you have. Chances are people arent going to want any of the parts you put on there, if you buy other stuff. There are a few good factory heads but none of them flow like modern heads. Keep a block for yourself to play with. if you can do machine work, align bore the block, order up some forged pistons .030 over and go to town. Big cam high compression v8s are a lot of fun :evil2:

 

[Doward]

mmm... Pontiac 400 ftw. I love the old school Poncho motors!

That said, if anyone built a girdle for the weak webbings of the Olds 403, you'd have a ridiculously rev-happy motor right there! How's a 4.35" bore with a 3.385" stroke sound to you?

Too bad about those windowed mains, though

 

[bmoss85]

mmm... Pontiac 400 ftw. I love the old school Poncho motors!

ive heard that the pontiac are alot better. people i know that have them always stress that they have a pontiac 400 not a chevy. i have no experiance with pontiac motors, why is it that everyone says they are better?

 

[webbs7mgte]

ponitac are better you guys say... well it jsut so happens i ahve a bare block and bare heads of a pontiac 428. worth building or no lol. the block is stamped as comming in a gto. sounds off cus gto's never came with them. But in ohio a couple of the guys working in the plant decided to drop the 428s in and buy them when they hit the floor. so i guess tis rare or something lol. but im goign to assemble the 350 and clean it up really nice and try to sell it. i can do machine work at school so on my spare block i will get the bore .030 over and go to town building a 383