How much hp and trq do you think this setup may deliver?

-350 bored 0.030over
-400 crank, 400 rods
basically bottom end is 383
-fully balanced
- comp cams xe274 (hydraulic non- roller) at 0*
- heddman 1 5/8 shorty headers
- double hump heads( 1.94/1.60), 3 angle valve job, polished combustion chambers, polished exhaust ports, screw in studs/guideplates
- RPM airgap intake gasket matched to head ports
- forged pistons, total of 10.5:1 CR
-crane energizer full roller rockers
-holley double pumper 650cfm
-holley red electric fuel pump
-mallory HEI (medium springs from, curve kit) w/taylor wires
- fluidamper harmonic balancer
- pwr steering delete(granny turning; s10 steering box)

I know RWP would be brutal due to my stock 7.5" 2.93 rear end,,,but im putting in a a BW 3.42 7.5"..no the strongest but as long as I dont put slicks on it and never hook up I think I should be fine.

 

Any particular reason for 400 rods? Pistons for 5.7" rod 383s are quite common.

It should be well over 1GFWHP/ci, but I think you're going to restrict it with the heads, carb, and headers.

I can't get past the 400 rods part. Just not a good idea.

Whatever rods you end up with should be good parts. You're going to be spinning this thing pretty good.

 

thanks for the reply

Well one engine builder I am good friends with suggested the 400 rods along with the forged pistons that would result in a very balanced setup. Also all the necessary clearance issues will be taken care of......and as far as the heads go I was really thinking of going to Vortech route,,,,however with the state of my double humps, he is incredible with headwork so he will rework them a bit to yield good flow.


*he said that the 400 rods 5.556 or 5.566 I cant remember, will be fine and will result in quicker revs as they are shorter....a combo he tried and got 478hp/526trq.(Thats only with an edelbrock performer intake)
....but every engine is different so im not jumping for such greedy numbers


Also I know the carb is a "650" cfm...however the mainbody 750 upgrade should make up for any airflow requirements of the extra cubes.

Also I can barely fit 1 5/8 primary headers.....so I will suffer whatever losses due to this. Also I have 3" single exhaust with a crappy dynomax super turbo( i guess some type of flowmaster will flow better but I am concerned about crank HP for now).

 

WHAT HE TOLD ME THE OTHER DAY

"the wieght of the 400 rod with the forged piston is the same weight as a 400 rod 400 piston so your not changing the rotating mass. Also with the 5.565 rod you dont have to clearance the pan rails as much as if you used the 5.7 rod. Also i think the 400 rod 5.565" u can rev faster and harder because everything is shorter and quicker"

Also the carb he used ended up being a 700dbl pumper

He reccommend 69 jets in the primarys with a 6.5 power valve and 78 jets in the back as it has proved very good in previous 383's hes built up.

 

I must have missed the part about the Proform main body (still don't see it, actually). That's the combo I'm using on the 396 (650 DP with the Proform body). Without a choke, it isn't the best street daily driver stuff, but it is sweet on the track.

I'm not sure I buy the 5.565" rod/forged piston weight thing. Also haven't heard that short rods enhance rev capability. I'd think they would hurt it, actually. But, that's more of a topic for the Tech forum than the Carb forum.

Word is the Dynomax flows better than a Flow. That's an Exhaust forum topic.

 

well thats perfect,,,i guess i dont have to change my muffler...

but yeah,. like yourself I was also questioning....."a 400 rod?????" but he has built some crazy reliable plants before,,but I will ask a few more people////then again things do usually sound like they wont work "in theory" however when someone have done it there is something that explains how kit was pulled off,,so I will ask a few more people about that

 

Yeah, I've got a Flow...

Do a search on the Board for "long rod". I'm sure you'll have plenty of reading to keep you busy for a good long while.

 

well it seems like "peak" hp is slightly greater with 5.7 or taller rods....but from what I have read the 5.565 rods will produce a greater earlier torque range and will help reduce clearance issues.

I think I will go with the 5.565 as this is going to be a street engine with 2500 stall and I de rather have more torque earlier than the little bit more higher up requiring a sturdier bottom end and higher stall converter( which seems like a bad mix for street).

Therefore it appears like the 5.565 rods will be the ones i will go with, i will still double check with this one other engine wizard.

I am looking for about 450+ horsepower and equal or greater torque. I will be running a 2500 stall as the greater torque will be lower down and the lower stall will take advantage of this rather than just spinning right past it.

I hope the user with the blue brothers guys can hop in this topic..as I noticed in one thread that he built a 383 with the same heads that I am using...and had some wicked numbers layed down

 

Is this guy a real "engine builder", or just a guy who happens to have built an engine or two?

 

this guys been professionally building race engines at a local machine shop....and the other guy I referred to as the wizard which i didnt ask about the setup yet has been building for 45 years..he s the owner of a race engine building shop....so I personally would never question their knowledge....but yeah..i will ask the guy thats seen every engine combo there is....the one thats been doing it for 45+ years....ill c what he has to say about this.

 

I'm not a real engine builder, but he's saying some things that are a little scary. The 400 crank/400 rod/350 piston idea is how 383s were made back in the day before aftermarket parts were widely available. A 400 crank would have its journals ground down to the smaller 350 main size. 350 pistons and crappy stock 400 rods were the only combination available that would fit. Now that there are aftermarket parts available though, there's no reason to modify and use the stock crap.

The combination he's talking about isn't going to magically make potential clearance problems go away. It could fit, or it could need more clearance work. The fast reving bit makes no sense, but I especially don't like the way he says it's going to produce a "very balanced" setup. That combination is going to need no more or less balancing than any other setup using a forged piston and a better 5.7" rod.

 

well everythings in the air...thanks for your reply....I will keep researching but In your opinion should I just go with the 5.7" rods and get the full balance like I wanted to in the beginning...
but like I said, he just told me this yesterday, so he might have thought over what he said by now.....so I will check around..(but the issue here is about the 5.565 and 5.7" rod...correct..if there is soo much uncertainty I will just go with the 5.7 rods...problem solved..

 

Any time anyone tells you that you don't need to balance, you can pretty much just turn around and walk away.

You can't just pick a rod length without pistons to match. With a 5.7" rod, you'll need 383 pistons with wrist pin height to match. Regardless of which rods you use, you might need some grinding on the oil pan rails or at the bottoms of the cylinder bores. Cam clearance could also be an issue.

Unlike the 400 crank which would need grinding, an aftermarket 383 crank will drop right into your block a whole lot more easily.

 

oh completely! from the first roll I new that no matter what there is always going to be a proper balance needed and clearance work as the stock geometry has been altered.

I think I will go with the 5.7's after all as not many people have 5.565 with the 400 crank and 350 block, I think this due to no response about anyone with that setup. Therefore I dont really want to be a test pilot so I will go with the tried and tested rod of 5.7''

 

Using a 5.565" rod doesn't make you a test pilot. Like I said, that used to be the only way to build a 383. The lack of responses should tell you something about the desirability of still doing it that way now that better parts are available.

 

ok great, now that that is settled....can we please get back to the topic...this time i will go with the 5.7 rods,,,,,any estimates on the output of the setup?

 

Maybe somewhere around 375 HP or so at the flywheel. A lot will depend on the heads.