n100

I want to build a 350 to 450-500 hp. on pump gas Is this possible?

I've acquired a 350 from a buddy recently. He bought a lot of new stuff for it when he put it together but I don't think he matched things up very well. Got to look at his receipts and here is what he put in the engine.

4 bolt 350 machined .30 over

TBI swirl port heads (he thought they were "vortecs")

EDL-2116 Performer intake

EDL-9630 5/16 stock pushrods

Comp Cams 981 valve springs

Comp Cams xe262

Scat cast crank

stock rods

Flat top 4 valve relief hypereutetic piston

"Pieced together" quadrajet


That's about all I could find out. Obviously the heads have to go. I'd assume the cam to. Any suggestions? Possible to make that power without stroking it? I'd like to keep a budget of about $2000 but can up it if i really need to.

2airtime2

No, not possible for that budget. To get that kind of power from 355 ci you'll need nitrous or boosting.


You can get close to 400hp but still not for $2000, maybe $4000??? You'll need a $2000+ set of aluminum heads, a $1800 roller retrofit cam kit, I'm not sure if you would need forged crank and pistons for 375-400hp but that's all the power you'd be at for $4000.


You can get close to 400hp from a 350 for cheap (relatively speaking) money but every little bit of hp above that will cost big money. For me, and my weekend fun car, spending $10,000 for 500-600hp just doesn't make sense when I can have 375hp for $1637.


My project came with a very good condition 4 bolt main 350 so I decided to put just a little money in it vs. buying a crate 383 for $5000ish.


From Summit I got a set of new vortec (iron) heads, flat top pistons and rings (mine were dished), flat tappet cam (under $150 vs $1600 for roller retrofit), intake and carb. Based on a dyno report from Comp that I found online with my cam, less compression, and similar heads I have around 375hp for $1700.

Gordonm

For that kind of power nothing there except the block is useable. Even for 400 HP not much there is useable. That motor with those parts is going to be about 320 to maybe 350 HP. Not to bad and will move a Vette nicely but if you are looking for 500 HP you will be spending a lot more.

resdoggie

I'm into that hp range. At least $4K into my engine starting with the original L-82 and built from there. HP doesn't come cheap if you want reliability to go with it.

JoeMinnesota

Well, the weekend is only beginning and you asked an open ended question about opinions on an engine build on arguably the most popular engine in the hot rodding world. Strap yourself in, because in just a day or two you'll have more (and different) opinions than you can shake a stick at.

The first response is a good one - I just rebuilt my 350 to 355 with a retro roller and hypereutectics, and stock (pink) rods and stock forged crank with aluminum heads and intake. That cannot be done with a budget of 2000.

However, you have a block, crank, rods. I will argue that you CAN make 400hp or close to it with a (especially SCAT aftermarket) cast crank, nothing wrong with stock rods, and hypereutectics as long as you don't rattle the motor. Make sure you have good machine work, clearances are measured, and have it balanced - which will help with longevity of those parts. The 450-500hp you seek is NOT possible with the stuff you have. If you want that kind of power, sell what you have and invest in forged parts like redoggie and start from scratch, or build/buy something with more cubic inches. There is no substitute for cubic inches.

If you can be happy with 375-400 or so hp, that can be done with many of the parts you have, but the limiting factors will be heads and camshaft. The bottom end is important to support the basic motor and longevity, but the breathing will limit or provide power. Most of the aftermarket dual plane intakes are going to perform similarly in terms of power output, just with differing RPM ranges and carb heights. If it were me I would stick with a performer or performer RPM assuming you can fit that in. Nothing wrong with a quadrajet - my stock, rebuilt and tuned Qjet is supporting 392hp and 413lbft no issues. In my case the camshaft is 224/231@050 and .510 lift which is a pretty choppy (nice) cam for a 355. You can get similar profiles in a hydraulic or solid lifter flat tappet to help keep this within a budget... this is where you find a good set of budget performance heads (they don't need to be aluminum, but go that way if you can) and then get proper input from the cam companies for best power in your combination. Keep your compression at 9.25-9.5 with iron heads and you can higher with aluminum and get away with it.

Good luck with the project and, again, prepare for a lot of opinions and advice here. Some of that will be very good advice. If it were me and I had my mind stuck on 450 plus hp, I would buy or build a 406 and be done with it. It also depends on what you plan to do with the car, and the balance of your drivetrain; if it is a cruiser, 400'ish horse will provide a lot of fun with the right gearing, etc. No matter what you decide, I don't think a reliable 450hp can be done on $2000. I usually figure $10 per hp and then tack on another $1000 if you go roller.

jb78L-82

Reliable 500 Gross HP can easily be done from a 355 BUT not for $2,000.

Resdoggie and my L-82 355 are somewhat similar builds and I did mine for about $5,000 but some of that number was for the machine work, assembly of the bottom end parts, new oil pump etc...basically I paid for a short block assembly BUT I used JE Forged Racing pistons, Howards Roller cam, reconditioned the Forged L-82 crankshaft, reconditioned the Forged L-82 rods, etc. The single biggest bite was the AFR aluminum heads for $1,500 back in 2013 and the roller cam/lifters for $700, also in 2013.

HeadsU.P.

Caution members. Sharp edges on can of worms opened.

Half of your budget will be gone on a roller cam. Or you can go flat tappet w/lifters for $200 (new springs will come w/better heads)

Keep in mind the add-ons. Thats what really jacks the cost up. Its called; while I'm at it. Example:
New timing chain set, better & longer pushrods for guide plates, special headgaskets for alum heads, ARP head bolts, thermostat, thermostat housing, intake bolts and then all the other gaskets, break-in oil, filters and on and on. Next thing you know, you wonder where all the money went. Its easy to come up with a budget for the big stuff. Its the little add-ons that really add up.

Comp Cams has a simulated dyno program on their web site that shows H.P. / torque results by swapping out cams, intakes, heads, exhaust etc. Its a rough power estimate, but none the less, interesting.

Krystal

Not sure about the price..you probably have to spend more money.......but I wonder why you'd resist a "stroke" increase.

I recently went this route......a 383...... it makes "peak" power in the range you're talking about.......but it comes with an advantage that might be pretty tough to match in a 350. The big wide torque band of 400 ft pds plus from 2500RPM- 6000RPM is the real advantage I never truly appreciated in a stroke increase.

Sure if your going to the race track and your car is standard shift that won't ever see south of 3000RPM maybe you'll never really need or miss the low end "grunt".......but on the street the difference is CRAZY.

My new problem these days is all about traction off the line ......and that low end torque is something that you will feel vs a 350 in every day driving situations. The 350 this new motor replaces was no slouch. At 10:1 and good heads and cam it made lots of power.......and in the upper RPM range the 383 feels just a bit stonger........but it's down low in the RPM range the 383 feels like an amazing increase in power. Hard to beat that on the street.

Sorry I didn't do this years ago.

cv67

Get the best 180-195cc head you can get your hands on, a known good carb 650-750 and a larger flat tappet 10 geg +- larger you could hit 400ish give or take.

OldCarBum

So here is a reality check. I just spent $563.00 for Crower roller rockers, $522.00 for roller lifters, $500.00 on a custom grind camshaft, $2,088.00 on Edelbrock heads, $108.00 on valve covers, $460.00 on an Edelbrock performer RPM air gap intake, and I'm preparing to order my forged stroker crank, h beam rods, forged Pistons, rings
, etc, etc, etc and the list goes on.
Without stroking your 350 I think you would be hard pressed to get the hp you are looking to obtain.
And unless you want to chance failure and build it with cheap China made parts I doubt you could do it for under $5,000.00.

derekderek

The short block is not a bad start. Decent crank-pistons. All could be better but should live at 400 hp and 6500 or so rpm. And i assune this is already paid for and not included in the budget? So he got a vortec intake and TBI heads. I don't like vortec intakes. That lack of center bolts is begging for a vacuum leak. Sell it. The heads? Worth about a nickel a pound these days. You might get 50 to 100 on ebay. Buy a set of vortec heads and a 650 holley and you have around 350 hp as-is. You want more? heads-cam. Intake. What will fit under your hood?

n100

Wow thanks for all the replies guys! At work so I will have to re read through this later. However I knew something was bugging me last night I don't think that intake could fit on TBI heads so I went out there and they are actually 906 vortec heads. Does this help me out at all if I want to drop my goals to say 400 hp?

like I said will respond in more depth later!

derekderek

better cam and you are there...

ctmccloskey

There are ways to make power without killing your budget.

I have a 1968 Corvette that came with a 427, I took it out to rebuild and since I was in no big hurry I used a 350 four bolt block with the old Double Hump heads and dropped it into the car during the rebuild.

The compression ratio was about 11-1 and it really liked premium gas. On the intake side I used an Edlebrock dual plane manifold and I installed to a set of Crane 1.6 roller rocker arms. Then I ditched the Quadrajet for a Holley vacuum secondary 750 cfm carburetor.

I never tested this engine on a dyno but it was "quick" on the STP dyno. My car has a 3.36 rear and I was out running a fully Restored 1970 LT1 consistently. From a standing start my little engine propelled the Corvette to a 13.2 in the quarter mile, I was proud of that little motor until I installed my rebuilt 427 with its 12.25-1 Compression ratio. Now with its 427 the car dropped into the 11's while spinning it's rear tires till past the 1/8th mile mark.

The old saying about "There is NO replacement for Displacement" is very true. However, I am a big believer in using higher than normal compression to make the engine more efficient. It is a great way to make some serious power if you want to with a smaller outlay of cash.
Look at the systems designed by Snow Performance for injecting windshield washer fluid into your engine while running. It allows me to put in 87 octane gas into my 427 without destroying my engine.

High Compression has been the "Great Equalizer" in my engine!

Good Luck and don't give up the quest, there are several ways down the path to making power. Getting it to "hook up" may be another problem....

derekderek

ok, you are talking about your budget and you are talking about this assembled? fresh? 355 engine as if it is already yours and paid for. cuz it is an easy $1500 in parts. did a shop balance and assemble it? $500 more. assembled by a backyard a$$hole like me? or still in pieces? and how much was it if it isn't prying? and is it part of this budget?