easyrider394

I want to build up my 305 TPI, and I would like to get around 300 horse out of it. Anybody have any suggestions as to how I can pull that much power out of that engine. I have a borla catback, as my only mod as of now. I was thinking cam, porting and polishing the heads, intake, slp runners, fuel pressure regualtor, headers, larger throttle body, underdrive pulleys, high flow cat. I havent decided what cam to go with yet, I wanna stay hydraulic (dont ask why). Anyone have any suggestions

mikobu3

cam and heads with headers should get you to the 300 hp range

Tibo

iTrader: (15)

The aluminum vette heads, Torquer S/R or Vortecs are your best bet for cylinder heads. Vortecs have the higher combustion chamber though. Aluminum heads are, well, aluminum. Slightly higher compression, less weight. Torquers flow more and are the easiest to get and deal with.

Cam is usually the last thing to buy. Make sure you match it properly to your heads/new TPI system/streetability you want. PROM tunig is always a must.

Higher compression flat top pistons. Everybody and their brother seems to run great on 10.0:1 cr. That is where an amount of power lies.

Other little tricks like the 1.6 roller rockers, baffled oil pan, baffled valve covers, underdrive pullies, aluminum driveshaft etc.

Porting the plenum, runners and intake to flow more. Port matched to gaskets. aftermarket runners and intake. Bigger fuel injectors. I think the formula is:
lbs/hr x 16 = horsepower

A good cooling system

That should do it.

IceBlue91z28

I built my 91z28 305 TPI to about 300+ hp or more and the it blew up and i got a 350 and its better but if you want to build your 305 heres what I had done to mine and it was fast:

k&n filter
gutted airboxes
world torquer 305 heads
crane gold race roller rocker arms
tpis airfoil
flowmaster american thunder 3" exhaust
removed cat
headman smog legal 1 5/8 headers
160* thermostat
hypertech thermomaster power chip
hypertech cool fan switch
accel 300+ digital igniton
accel spark plugs
msd 8mm wires
and i had 3.73 rear end which made it a lot quicker

the heads make the biggest difference on the 305, you might want a new cam too since you have an 86

just something to go by

gtaeric

On my last GTA, with the 305tpi and 5speed, I had k&n cone filter (in place of airbox), TB flow piece, ported plenum, adj. fuel pressure regulator, and Flowmaster exhaust and I dynoed at 211hp and 277lb/tq at the wheels. so figuring drivetrain losses, thats about 245hp and 320tq at the flywheel. Thats a good start, but i bet headers, 1.6 rockers, computer chip, bigger injectors, (24lb/hr) ...

injector lb/hr= [expected horsepower * .5]/[#of injectors * .8] where .5 is the specific gravity of gasoline, and .8 is 80% injector duty cycle.

and either better runners, or the TPIS manifold would have put it close to 300. or you could just do the mods i had and then run a 75shot of N2O.

ERICCAMARO

get the 335 stroker kit. built 305 horses on a tbi engine, imagine the possibilities.

80smetalfan

why waste the money stroking a 305? i'd say a good heads and a well matched cam will yeild the most HP towards 300. as everyone else has said now, good headers and TPI mods well be neccesary too. i'd also get your heads ported, to be sure.

but if you're gonna spend the $$$ you need to stroke the 305, you might as well get a 350....

Clemson327

iTrader: (4)

Where can I get the 305 stroker kit?

Adam

ThirdGenFire

Not really worth it just build the 305 as is but if you like Power House sells one. So does P.A.W.

ThirdGenFire

The LB9 makes great torque so by adding some runners from AS&M will help. For street driving and road coruse stick with the Long Tubes for low end torque but for all out drag racing go with an aftermarket runner design.
The power like all combos is in the heads and cam. My cam made a hugeeee difference. I picked a perfect street cam I feel. Its not too big and I may go bigger now that I have heads but the Compucam series from Crane(now the Powermax emissions legal)is a great cam choice.

Tibo

iTrader: (15)

Well, guess it's time to learn somebody.

The formula for an area of a circle is pi(r squared) where r=the radius and the radius =(Bore/2)

The formula for the volume of a circle is pi(r squared) x h
Where r= (bore/2) and h= height= stroke.

So we know plug numbers into the equation:

stock 305: [(3.736/2)squared] x pi x 3.48 = 38.1490

stroked 305 bored .030 : [(3.766/2) squared] x pi x 3.76=41.8831

stock 350: [(4.0/2) squared] x pi x 3.48 = 43.7310

Now if we were to plug those answers into another equation subtracting the new volume from the original volume we will get the difference
41.8831-38.1490= 3.7341

Then if we subtract the stroked 305 volume from the stock 350 cylinder volume
43.7310-41.8831= 1.8479

So between a stroked 305 and a 350 there is only 1.8479 difference.

Now do you recall that more cylinder volume combined with a longer stroke makes more torque. Combine that with a torque set-up like TPI and you get FUN.

You will be very happy with a stroker kit, ask anybody with a stroked motor if there was enough of a difference to justify stroking it. You will almost always hear them say yes.

Of course stroking it will cause added problems like clearence issues and a different camshaft thought process. (Small bore loooong stroke)

cgb

All the math was great. And if someone wants to stroke a 305 GO FOR IT.

I think what he was trying to say was this...


ALL other things being equal, the 350 will make more power than the stroker 305. Trust me, I've seen the dyno's / track runs of one, and needless to say, after the guy added up what he had in the long block, he could have built a 350 or 383 for the SAME price.

SBC's are very interchangeable..that's one of the reasons they are so widespread in use in the hot rodding world.

If it were me, and it's NOT, if your 305 runs well now...just make mods to it that will EASILY transfer over to a bigger engine.

It's a great opportunity to learn the basics of building your first engine from scratch, since you have a good running engine to drive in the meantime.

All that being said...

300HP ( assuming flywheel HP ) is a fairly easy goal with the TPI 305. Tuning, as always, also plays a big part...

The World Products heads ( or better yet ported 305 heads....if done right will flow BETTER and be much cheaper ), the right cam, headers, exhaust, some free porting / clean up on the stock TPI components, and I don't see that 300 HP being a problem at all.

Headers / exhaust is worth an easy 15 HP on these cars. The right air induction system can gain a few ponies too..say 5 HP.

The right cam and heads are worth an easy 40-60 HP. At that point you're already real close.

So do what you want to your ride...that's why this hobby / obsession is so fun.

ThirdGenFire

I know the reasoning behind the 335 build up. I relize the greater capability of the 335 Vs 305 but if you are gonna stroke the 305 to make a 335 then just buy a 350. I was about to do the 335 kit but figured that if that was the case I might as well should have got a 350. If you recall the Silver Streak was a 335(If I remember correctly correct me if I am wrong)and it made some kick *** power so I know it is better than a 305 base motor. There is a guy on here that has a 335 stroked motor.
Here is his groups site TRC Performance

Clemson327

iTrader: (4)

The main reason I want to stick with a 305 is because everybody badmouths it and talks about how it is worthless compared to a 350. I just want to prove that you can make good power with the 305 on a budget. I also want to do it b/c nobody has a 305 with 400 horses. For anyone interested, I have the LG-4 crate motor, and if anybody knows anything about taking the computer control out of these suckers, their knowledge would be greatly appreciated.

ERICCAMARO

335 stroker kit is made by powerhouse I forget the website its something diffent but it was used on the '88 project silver streak. Im guessin if you have ported heads and the 335 along with the tpi youll make a good 325 horse at least.

ERICCAMARO

http://www.enginekits.com/catalog.pdf is the link where the stroker kit is offered. Its like 500 and for the horse power increase you cant beat it.

ThirdGenFire

I should be getting my car dynoed with my car club soon. I'll post the numbers when I do it.
My friend has a LG4 and has deleted the computer setup all together, it was fast and east he said. Get a different HEI(stock sucks and is ECM controlled). He runs decent. He ran a 16.1 last week against my 15.03. He has a Summit cam, Performer intake, 600cfm Performer Carb and Flowtech headers that goes back to a 89 GTA rear disc with 3.23's.

Tibo

iTrader: (15)

I don't remember who (convenient of me huh?) but there is a guy who has that much on the boards. There are a few other guys who have that on the bottle.

Clemson327

iTrader: (4)

Ya just had to burst my bubble didn't ya Tibo? Maybe I can get in touch with him somehow and see how he did it. I'm lookin to get 400 bhp all motor. Hope I'm not just being an idiot and trying to achieve something that can't be done.

TunedPort 335

I'm pretty happy with my 335. I think I'm the only person here who has one. Right now its approx 300hp at the crank.

Stock untouched heads
Stock untouched TPI intake
Stock tuning
Stock 19lb injectors
Stock catback with a Flowmaster muffler
Still had airboxes in it

347rwtq through the exhaust and I missed my peak torque... not too bad If you ask me. Yeah, a 355 buildup would probably be more powerful and have more potential...but its my first car and I wanted to build what I already had

I have since gutted my airboxes, installed a new TPS and IAC, putting on my underdrive pullies, and am Installing my 3" hooker catback, I need new tires so I can dyno in 3rd gear... I'm hoping for 260+rwhp and 370+rwtq through the open cutout.

It's all up to you, bro

Clemson327

iTrader: (4)

I have seen the videos of your car TunedPort335, and I just wanted to let you know that it is pretty dang nice.

Do any of y'all believe it would be possible to get 400 hp at the crank with a carbureted 335 stroker? I've never rebuilt an engine before so this combination may be way off, but this is what I was planning to do:

-bore .030 over
-stroke to 335 (I believe there is a kit from Powerhouse that includes most everything needed to do this including Keith Black pistons that give somewhere around a 10-11:1 compression ratio)
-Edelbrock Performer RPM Air Gap intake manifold
-Holley 750 cfm VS w/electric choke
-World Products S/R Torquer heads (1.94/1.50 intake/exhaust, 200cc intake port, 58cc combustion chamber)
-Hedman long tube headers (1-5/8" primaries, 3" collector)
-not sure about exhaust yet, maybe true duals with high flow cats and chambered glasspacks or flowmaster 80 series with a custom y-pipe
-exhaust cutouts before cats
-new high performance distributor (maybe Mallory???)
-Cam???? I am thinking 230-240 duration @.050" with 112 LCA
-new fuel pump.....any suggestions??
-new lifters (obviously), pushrods, and 1.6:1 roller rockers

I am sure I am going to be called overambitious for this, and chances are my projected setup is all wrong. I will gladly accept any constructive criticism or advice as y'all know a heck of a lot more about this than I do. I am not real concerned with emissions as we don't have to worry about testing here in the great state of South Carolina. Once again I will appreciate any advice but please no "just ditch the 305 and get a 350." I want to work with what I have since this if my first engine rebuild. Thanks in advance for any help.

Adam

TunedPort 335

Clemson327 - I don't know much about carbed motors, but honestly that sounds like a really nice combo. I would almost gaurantee that it would make 400crank hp. But I beleive thats the point where the 350 would take over, because the engine will breathe alot better (4" bore, more room for airflow, less valve shrouding).

But yes, I think 400hp is possible out of a carbed 335. It's all in how everything is matched up. Im making around 300hp crank give or take a few, and thats with one of the most restrictive intakes on a SBC ever made, and a mild cam. (Mine is .210/.220 duration, .480/.480 lift, 112 LSA.)

ThirdGenFire

His name is Tim Burgesy or something like that. He has a 11 second 305 with a 125 shot of the juice. he sent me his mods list and other small items 3 months ago. I'll remember his name sooner or later.

neubauej

Willie has the fastest/quickest 305 that I know of, you may want to try him. He is procharged though...

Tibo

iTrader: (15)

Better rephrase that tunedport335. Your the only one right now who has one in their car. Mine should be finished in a month or month and a half.

I beliveve that the torquer's are rated at 171 or 177 intake.
If you are worried about highest output or streetability is the real question here.

N8MAN1068

I'm hoping to get at least that with my 85 305
lt1 intake
comp cams NX262
113 heads
coated hooker 2460's
cut out

hopefully i'll have it running by the end of the month. after that, i need to get it inspected(if anyone is a mechanic in my area, pm me for an easy $50..lol), then it's off to the dyno for some base#'s.
Then i'll have to work on tuning and what not, and getting it setup for the juice.

ThirdGenFire

Willie has run a 12.00 I belive. Tim has gone 11.6's or so.
Either way thats great to hear for a 305.