400-450hp 355 on a budget?

[Pete357]

Just looking for someone to tell me if im crazy before i call my race engine shop for machine work and parts tomorrow and sound like i lost my mind.
Im looking to build an honest 400-450 hp 355...or 357, depends on if the guy doing my machine work says my bores are good to go. I will be doing all the assembly work on her myself and already have it down to a bare block to save some buck there.
Looking on going with the weiand 177 blower on top of my 355 to help get me there. Blower kit i priced out at $2359 through summit but my builder is going to see what he can get it for. Carb to top off the blower is $580, its the 750cfm holley blower carb. I priced out a dished forged piston and ring kit at a 26cc dish for $720. I was checking out this cam and lifters for $225 http://www.summitracing.com/parts/CRN-113822/
Set of larger tube headers $160. Then i fig rod and main bearing around $40. Pricing everything through summit i had a cost of $4130. My builder said he would see what he can get me parts for if its any cheaper. Heads i have that are paid for are the 492 casting double humps. 64cc chambers and 26cc dish should plot me somewhere between 8:1-8.5:1 comp ratio right?

Final question do you think i can hit my hp mark with this setup and do you think im crazy for trying to do this motor for a budget with a max cap of $5500?

[fastwillie 696969]

just sayin
plan on spending more than you think you budget

[Pete357]

Yea im planning on it, obviously there is still oil pump, water pumps etc etc...i calculated roughly $4100 on parts through summit, my machinest/builder said when i find out what i want to do he will see if he can get stuff cheaper but then machine work on top of this. I really dont think i will be able to swing over $5500 on motor without sacrificing other stuff i wanted to do to the truck before spring. Am i crazy thinking i can pull off this set up for that price and do you guys think ill be in my hp range?

[Pete357]

I know it all comes down to when i call the man tomorrow i was just looking to see if im still in the realm of reality.

[turbo350]

A bit of advice. Years ago I had a builder with a good reputation build my old 406. It was over 10 months from the time I dropped off the short block until I picked it up ready to run on the dyno. I realized costs would be high but I felt I was prepared for a little over budget. In the end the cost was waaaay over budget. I had a heck of a strong engine after it was done but way over my estimated costs. MAKE YOURSELF A BUDGET AND STICK TO IT. I listened to and trusted him a little too much and his cost was actually not cheaper than the catalogs. Keep in mind builders and machinists have to make a living to, you just need to decide how much of it will be at your own expense.


Unless you are going racing do you really need the most expensive set of heads or the most expensive cam? Just food for thought from someone who has been down this road once.

Use your own head and invest your time to research what you need, and shop for your best prices.

This kit looks pretty good price wise and I've heard the quality is good to!

http://www.northernautoparts.com/Pro...ctModelId=1666

[Marv D]

HP is 'over rated' This magic 400HP number is just like splitfire plugs and trickflow heads. It's been beat into our heads with every add in every car rag. FORGET the numbers and build for the most torque in the rpm range your looking to use. If I build you a 327 that makes 500normally aspirated horsepower on a single carb,,,,will you be happy???? NOT on the street because I'm going to built it to make this magic HP number around 7500 - 7800 rpm. Even if you use a 26" tire and 5.43 gears, you aren't going to be spinning 7500rpm anywhere between stoplights are you! A 500HP small block is going to make 75-100HP in the DRIVABLE range of street driving (1500-3800 typically)

Look, I know you said 400-450 was the goal, but the point is the same. High HP small blocks dictate high RPM!!!

Let's use the 6800RPM HP peak that is typical of a stout small block (400-700HP all peak around this same range of 6800-7200 on a real dyno)

If you use a TH350 or TH400, With a more typical 3.43 gear, and a 28" tire like you would find on a Camaro or sedan,, not on your truck, ..... but for example.

You are going to have to hold it in LOW gear to 65mph make use of that 6700rpm peak. And that does not even take into account optimum shift points for an after the shift RPM to make best use of power curve. Tell me how your going to use that on the street????????????

Easiest and most bang for the butt-o-meter on the street is cubic inches. If you want to keep your 4" bore,, cool. stroke it to a 383. Parts are cheap, and a 383 is as easy as falling off a log to make 1HP per cubic inch and MORE IMPORTANT,,, 400+ pound feet of torque in a DRIVABLE RPM range. 9.5:1 compression and pump fuel, Decent heads that flow (a MEASURED, not advertised) 240ish cfm, a hydraulic roller to get the reliability and valve action to make good power below 6500, and a dual plane intake will make enough power to shred any tire you put on the truck,, and if you ever get it to hook,,, you will shred drivelines, transmissions, U-joints.......

Seriously, FORGET THE horsepower wars.

[bustedknuckles]

I don't think you're crazy at all. It is definitely do-able for that price. Sounds like it will fun to drive as well. If you are buying a crank, you should definitely consider a 3.75" stroke and build a 383. "there's no replacement for displacement"..... Just know that all the little stuff adds up, (oil,plugs,water pump, t-stat, filters, gaskets, sealer, etc..) The list goes on and on. But $5500 should build a helluva motor.

[Super73]

To Marv's point, 400ftlbs of TQ at 5,252 is 400hp at that same RPM. TQ is the force that moves the object where HP is the amount of work the TQ will do over time.

[C20-67_N_MO]

I would agree, build a 383 ci engine and put that lil blower on it and you should have one helluva good street motor.

[shortbed70]

Im off the numbers train!! Everyone asks how much power I say let's go for a ride and you tell me. My motor might make 330-350 hp and probably the same torque but coupled with 28" tire 3.73 gears and 700's first gear it's a monster... Would I like more, Hell YEA but then it's a matter of how often you want to buy tires or other parts. If it was me flattop motor, 6" rods good heads/topend combo or do your research and have fun!
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[Pete357]

I here the 383 + blower combo is actually pretty tricky to pull off between comp. ratio and getting a blower cam properly clarenced and considering the $2300 blower is consuming alot of my budget i think i best stick with the 355 idea haha. I do want drive ability and torque over hp though, just kinda set my goal to beat a buddy on the dyno. Did talk to my machinest/builder and he claims with me doing the tear down and assembly work i shall be plenty in my budget and hitting my hp goal! Ill have to give you guys an update with dyno numbers as she gets wrapped up.

[shortbed70]

So ur building a blown 355?
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[Pete357]

That's the plan
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[VA72C10]

I think what Marv was saying is you can make your 400HP goal w/out the supercharger on a well built 383 that will be much more streetable than a 400hp blown 355...

He's got a lot of experience!

[hotrod 80]

I vote 383 325-375 reliable hp and a broad flat torque curve across the board . Buy good pistons and add 150 shot when needed wanted .

[BigDan3131]

400 is very easy with all the modern cams we have now. That little blower should add a bit of each.

[Bad70sbchevy]

I guess I'm crazy, my 355 is making around 425hp on pump gas without a blower and drove it as my daily driver for 5 years.

[chopped68]

I'm running a 383 that puts out over 400 ft. lbs. of torque from 1500 rpm on and has over 500 hp.definately nice to have that low/mide range power and torque.it's a full roller motor and cost about $4600 from the oil pan to the air cleaners(tunnel ram/2 holley 390's)but I did alot of parts hunting and found several good deals on ebay and craigslist.

ken

[Pete357]

So, just curious, why do most seem the have the thought that a blown 355 is going to be low on torque? I mean its not like a blower is just a hp adder, from what i understand they do more for torque than hp.

And happy thanksgiving to everyone here!

[Super73]

Pete,

Since HP is a function of TQ * RPM / 5252, any increase of torque directly increases HP. But here is the kicker. If you are looking at increases bellow 5252rpm, you will always see more TQ than HP, above 5252rpm, more HP than TQ. HP and TQ always cross at 5252rpm.

Example:

TQ - RPM - HP
300 500 --- 29
300 1000 - 57
300 1500 - 86
300 2000 114
300 2500 143
300 3000 171
300 3500 200
300 4000 228
300 4500 257
300 5000 286
300 5252 300
300 5500 314
300 6000 343
300 6500 371
300 7000 400
300 7500 428
300 8000 457

[68 C-10 KID]

There is a lot of HP and TQ numbers being posted up here. Curious if any one has the dyno charts they can post?

I'm going to side step this and add my 2 cents. I'm a vivid fan of the 6" rod 400sbc. You will have street ability TQ and HP numbers that makes the other combo's humble.

[Pete357]

http://www.carcraft.com/techarticles...d/viewall.html
I was just scoping out this article doing some more research. Looks pretty much what im looking to put together minus the vortec heads, heads probably wont be in my budget however that is working with a bone stock junk yard std bore 350 and a little 142 blower, between my .030 over and the larger 177 blower if i spool her up a little i think i may be able to hit similar numbers. But very excellent dyno chart to show the street-able torque a blower is capable of i think.

[Pete357]

I mean by no means am i trying to show any dis respect to any of you guys by sticking to my guns on the blown 355 idea. Just seems like everybody and their uncle does a 383 at some point in their life. I want something that is going to be different around here when i take it to car shows and i think a little 177 blower hiding away under the hood will be pretty different, i haven't seen much of that around car shows here but i do see a handful of air cleaners with 383 on top of em.

[bustedknuckles]

Originally Posted by Pete357

http://www.carcraft.com/techarticles...d/viewall.html
I was just scoping out this article doing some more research. Looks pretty much what im looking to put together minus the vortec heads, heads probably wont be in my budget however that is working with a bone stock junk yard std bore 350 and a little 142 blower, between my .030 over and the larger 177 blower if i spool her up a little i think i may be able to hit similar numbers. But very excellent dyno chart to show the street-able torque a blower is capable of i think.

Alot of their power is coming from those heads. They flow worlds above any other production iron head (excluding double humps) The larger blower will help, but heads are a big factor. The more air you can get in and out, the more power.

There is nothing wrong with a blown 355, and if thats whats in your budget, then do it. To me, a blower on a 355 would be cooler to look at than a n/a 383 any day.

[Pete357]

So...when you say excluding double humps is that a good thing then that im working with the 1970 lt1 double humps?