odd 350 build ideas
11-30-2016, 11:43 PM
#1
Member
Thread Starter
iTrader: (6)
Join Date: Apr 2013
Posts: 385
Likes: 0
Received 0 Likes
on
0 Posts
Car: 91 ws6
Engine: Carb'd 334 stroker
Transmission: T5
I'm looking for a few ideas on an engine build for my trans am. It's being built for autoX, NASA AE class. By my math, which im guessing and pulling numbers from my *** sincem I dont have a scale, I would be limited to 366 hp at the wheels.
Originally, was just going to do a vortec 350 with a moderate cam, weiand intake and Holley 650, didnt plan out exactly what cam.
Went and looked at a motor from a 97 1500, had a complete and total brainfart and forgot to check the castings. Yeah, it's a 305.
So I'm left with a few options, all must be done on the tightest of tight budgets.
Finding a vortec 350 around here is..difficult, and expensive when they do pop up. Currently I was thinking to find a roller 350, clean up these 305 heads, put in larger valves, beehives, 1.5/6 rockers, and then a cam.
It will be 80% street use, t5 at first with a t56 down the road, 3.48 rear.
Must stay roller, and looking for something that makes power 1000-4000ish.
Any suggestions?
Option b is to put these heads on the current 305 and go from there, but 366 from a 305 seems like a stretch without spending buku dorra.
Originally, was just going to do a vortec 350 with a moderate cam, weiand intake and Holley 650, didnt plan out exactly what cam.
Went and looked at a motor from a 97 1500, had a complete and total brainfart and forgot to check the castings. Yeah, it's a 305.
So I'm left with a few options, all must be done on the tightest of tight budgets.
Finding a vortec 350 around here is..difficult, and expensive when they do pop up. Currently I was thinking to find a roller 350, clean up these 305 heads, put in larger valves, beehives, 1.5/6 rockers, and then a cam.
It will be 80% street use, t5 at first with a t56 down the road, 3.48 rear.
Must stay roller, and looking for something that makes power 1000-4000ish.
Any suggestions?
Option b is to put these heads on the current 305 and go from there, but 366 from a 305 seems like a stretch without spending buku dorra.
12-01-2016, 07:28 AM
#2
Supreme Member
Join Date: Apr 2013
Location: North Salt Lake
Posts: 1,353
Likes: 0
Received 1 Like
on
1 Post
Car: '86 Camaro, '94 Camaro, 3 others
Engine: LG4 ->L29, L32->LR4, L36, LG4, L31
Transmission: 700R-4, T5WC, 4L80E, SM465, 4L60E
Axle/Gears: 3.42, 3.23, WTB/WTT 2.93
Re: odd 350 build ideas
First things first: pull the intake valves out of those Vortec 305 heads, because some Vortec 305s were swirl-ports. If that's what you have, they'll never get you to 366 HP.
12-02-2016, 10:43 AM
#3
Member
Thread Starter
iTrader: (6)
Join Date: Apr 2013
Posts: 385
Likes: 0
Received 0 Likes
on
0 Posts
Car: 91 ws6
Engine: Carb'd 334 stroker
Transmission: T5
How do they respond to larger valves?
12-02-2016, 12:35 PM
#4
Supreme Member
Join Date: Apr 2013
Location: North Salt Lake
Posts: 1,353
Likes: 0
Received 1 Like
on
1 Post
Car: '86 Camaro, '94 Camaro, 3 others
Engine: LG4 ->L29, L32->LR4, L36, LG4, L31
Transmission: 700R-4, T5WC, 4L80E, SM465, 4L60E
Axle/Gears: 3.42, 3.23, WTB/WTT 2.93
Re: odd 350 build ideas
I long ago lost the paper with my notes from the one time I had both Vortec 305 L30 heads in front of me, but a quick Google shows the 059s to be non-swirl, so IDK. That's why you check.
If they're non-swirl, then you can big-valve them fora small improvement, but for less money you can go to Pick-N-Pull and get a good used pair of the L31 Vortec 350 heads, they're worth the $80. Then get them shaved 0.030" for compression on your 305.
If you got swirl-ports, they will make excellent torque below 3500 RPM, but there's no gain from bigger valves.
I've spun a stock LO3as high as 6000 RPM, in gear, so I know the swirls aren't a total disaster. But when you takea420 HP cammed Vortec 350 and put LO5 swirl-ports on it and lose 90 HP, you know the swirl-ports aren't as powerful as their low-RPM TQ suggests.
If they're non-swirl, then you can big-valve them fora small improvement, but for less money you can go to Pick-N-Pull and get a good used pair of the L31 Vortec 350 heads, they're worth the $80. Then get them shaved 0.030" for compression on your 305.
If you got swirl-ports, they will make excellent torque below 3500 RPM, but there's no gain from bigger valves.
I've spun a stock LO3as high as 6000 RPM, in gear, so I know the swirls aren't a total disaster. But when you takea420 HP cammed Vortec 350 and put LO5 swirl-ports on it and lose 90 HP, you know the swirl-ports aren't as powerful as their low-RPM TQ suggests.
