....gm PM rods with our 305's. are cranks and rods for late 350's and 305's the same?im tring to get a game plan for a strong bottom end on a reasonable budget. anyone know where to get forged pistons for a 305?
.........im thinking 12psi.

 

If you're building an engine from scratch (and since you're looking for pistons, you are), don't waste your money on building a 305. You will be so much happier with building a 350 or larger. Anybody that spends money enhancing a 327 or smaller is just plain foolish.
Chevy has made the 350 for over 30 years. How long did they produce a 327? 305? There's a reason for that, the 350 is a superior engine. The 305 is a people moving smog engine. It was never designed to make any appreciable horsepower.

As A general rule: You will make more reliable power with a mild, large engine than you will with a max'd-out small one.

[This message has been edited by offroader (edited April 02, 2001).]

 

Good question sy.

I am also looking fo some highperformance pistons and rods. Be prepared to dish out like 600 bucks for a really good ligthwieght set. But I think that lightwiegth pistons and cranks can free up some weight in our motors and help it reach higher rpm's. i think pistons would make a big difference. I say this because I saw a show on a concept Cadilac DTS that Tim Allen had a say on its design. It was called a DTSi and they took the 300hp northstar motor and swaped rods and pistons and thats it. When they dynod it, it had 98 more HP! That was just from pistons and rods. Is 60 time went from like 7.3 to 6.5. When I look around for pistons I just see pistons for a 327 or higher.


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1990 RS 305 TBI T-5
.5" turbocity spacer
Summit 14X3 OpenElement W/k&N
Custom Exhaust
MSD - Wires, Cap, Rotor, Coil
Bosch Platinum +4 plugs
Metallic Red w/26,000 miles

 

reason im posting is because i dont really want to start from scratch. i believe i can use the stock block and crank. $500 for a set of pistons and rods sounds a lot cheaper than a $1200 short block, or $2100 for the 330 hp 350."the cheapest 350 performance crate motor" i really think that beefing my bottom end when i go for a rebuild will allow me to upgrade to whatever in the future, with out having to "start over" everytime i want to go a little faster. there are lots of TPI guys running boost on totally stock bottom ends, i just want a little more insurance.
this is really a three step process, so i dont have to shell out a lot of money all at once.

1. i want to build a 305 with 220-250 horses that gets great gas milage. should be in the ballpark with nothing more than an l98 cam and vortec heads, mabe roller rockers later on.

2. convert to an aftermarket MPI set-up, probably holley. (more power, more milage, infinate flexibility)

3. ATI procharger with intercooler. (10~12psi) should give me MORE than enough power without losing much milage or worrying about the bottom end. (goal is 380~400hp)thats about twice what i have now.

[This message has been edited by sy2449 (edited April 02, 2001).]

 

sy, it doesn't mater which engine you build. If you want a strong bottom end you should at least use ARP main and rod studs. This alone will strengthen it more than you will realy need for your setup. It will complement your rods and pistons you wsnt to use along with the blower in the future.

 

yeah man good luck. I'm doing my homework on beefing up my 305. Except mine is in a 91 caprice. I plan on S/Cing it. Dont listen to those ignorant jerks who descourage you saying the 305 is not meant to produce power. Total BS. That deserves a smacking.

 

Ahhh. A man with a sharp wit. Someone ought to take it away from him before he cuts himself.

Do you have proof that dollar for dollar a 305 can make as much power as a 350? Didn't think so.

 

not as much power as a 350, but enough! there is only so much that can be done with either motor, and i think the 305 will be more than enough displacement for what i want.

i have a 4.3 v6 in my syclone that eats ls1's for breakfast. by your logic that small of a motor would be a HUGE waste of time, yet i seem to be able to walk away from every camaro i pull up to, regardless of what their mods are, and i have very few mods. totally stock motor and turbo, just bolt-ons. the only car i know of that has a better 0-60 time is the ZO6.

ok so back to the whole reason for this post.....
the internals of a 305. are they compatible with a 350? they have the same stroke, just a smaller bore. so do they share cranks and rods or not?

 

Keyword there: Turbo. That and a CPU that's tweaked to maximize that combination is why the Syclone is what it is. A turbo, supercharger and for matter nitrous oxide all fool an engine into thinking it's larger than it is. It does this by increasing the volume of A/F mixture that gets ignited thereby producing more power.

I would rather have a 4.3 v6 than a 305. Why? The 4.3 is has the same bore stroke as the 350. The 4.3 I built for a friends desert racer so far has dyno'd 264hp @ 5500. And that's with a PROM just to get the thing running. While that may not sound like much, keep in mind that this engine would be in the 350-400hp range had it been a 350(remember same bore/stroke minus two cylinders).

If you want to settle for 2nd best, whom an I to stop you.
Answer: Yes.

 

Where is NJ Speeder at? I know he's going to want to reply to this "don't waste your time building up a 305."
Tim is going to take my L03 and build it up. I think it would be exciting to see a L03 stroked, large cam, good heads, awesome intake making over 330hp na. Could be an awesome bracket engine since going a few tenths and mph faster doesn't help. Also having one of the fastest if not the fastest na L03 could be a very cool title. I probably would have either built the old engine but I didn't have the time. I need my car so I through in a crate 350, was cheap and works great.

------------------
, Jon (350 TBI!)
91 Red RS w/grey int, sq stereo (Alpine v12, kicker solo, MB quart premium etc)

• Holley 670 TB unit w/ 1/2" spacer/adapter
• Edelbrock RPM vortec intake
• 350ho 330hp vortec crate motor
• 8" harm. balancer
• Stewart stage 2 water pump w/160 thermo
• SLP tri-y headers to full 3"
• Rebuilt trans w/ SLP shift kit
• Centerline 16x8's all around
• 36/24 mm sway bars
• Full poly bushings, even motor mounts
• SLP LCA and panhard
• Alston SFCs
• Edelbrock 3 point STB
• Global west steering brace aka wonderbar
• Eibach pro kit springs
• Bilstien high perf. struts and shocks
• All this and I still have AC

My websiteAny questions?

 

False, the 305 crankshaft has lighter counter weights. The 305 and 350 cranks are NOT a direct replacements for each other.

The rods are the same.

 

Ugh 305s are gay. Dont waste your time!!! The small bore is S H I T!!! 1200 for a shortblock? cmon, long block cores are a friggin dime a dozen! and the machine work + internals to build what you wanna build will still come in under 1200 and thats a bullet proof bottom end. Heads are where the power is and good heads dont work on 305s!
the whole idea of building up a 305 is retarded. I have one because it was free. No way in hell id build one. Small bore = S H I T

 

It's different, not **** Pablo. Maybe it's not the cheapest and doesn't yeild the best performance but it's unique. Not too many build 305s and for a good reason, not bang for the buck. It's not bang for buck unless you can had a complete engine for next to nothing. Either that or sell it for scrap metal . Still I think it would be fun to see a 305 kicking 350s at the track.

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, Jon (350 TBI! getting 23mpg highway)
91 Red RS w/grey int, sq stereo (Alpine v12, kicker solo, MB quart premium etc)

• Holley 670 TB unit w/ 1/2" spacer/adapter
• Edelbrock RPM vortec intake
• 350ho 330hp vortec crate motor
• 8" harm. balancer
• Stewart stage 2 water pump w/160 thermo
• SLP tri-y headers to full 3"
• Rebuilt trans w/ SLP shift kit
• Centerline 16x8's all around
• 36/24 mm sway bars
• Full poly bushings, even motor mounts
• SLP LCA and panhard
• Alston SFCs
• Edelbrock 3 point STB
• Global west steering brace aka wonderbar
• Eibach pro kit springs
• Bilstien high perf. struts and shocks
• All this and I still have AC

My websiteAny questions?

 

I wish we could get more out of our motors than 330hp. BMW and Mercedes can get 394 hp out of there 5.0's and that is without any mods. Is it just because of the TBI setup? How much HP can you get out of a 305 TPI?


------------------
1990 RS 305 TBI T-5
.5" turbocity spacer
Summit 14X3 OpenElement W/k&N
Custom Exhaust
MSD - Wires, Cap, Rotor, Coil
Bosch Platinum +4 plugs
Metallic Red w/26,000 miles

 

The only real advantage i see in the larger bore, (besides more displacement)is a better selection of heads, with larger valves. but i probably cant afford AFR's, (which is what id get otherwise) im really leaning towards the vortec heads, which i think have really good performance for the money. GMHTP is constantly raving about them, for both performance and cost. i mean really, if cost was no factor, id just call lingenfelter. i understand, that the parts for a 305, and a 350 are about the same, but i already have most of a 305. besides, i may reuse the stock heads for now, and upgrade to the vortecs later. that would make this build EXTREMELY cheap.

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91 RS
91 GMC Syclone