|03-27-2013 05:42 AM|
Get a COMPLETE 96 to 2000 350 vortec engine. You can pick up a good condition engine for less than $800. Factory roller cam and vortec heads are worth 50hp over the earlier non roller engines (like you have). Add a set of headers to make another 25hp.
Add a little more cam, better intake, and a little head work to make 350hp/380ftlbs.
If you what to make serious power then would then freshen up the engine, add a mild cam, drop compression to 7.5 to 8:1 cr, and add a turbo. 10 psi of boost will make around 500hp 550ftlb of torque on a mild 350. Use your megasquirt with bigger injecters (2x bigger).
|03-26-2013 08:05 PM|
See I am a little drawn back from just a H/C/I swap on a high mileage daily driver that goes on 200 to 300 mile road trips. I would rather it all be fresh as much as it gets driven..
I have looked around to see if I could find a 90's roller block 350. Just a bare one for around $100 , no luck and looked at 383 kits. For about $1100 you can get the stroker kit and have the machine work done on the block. By the time its said and done I will have $2500 in the 383. I can finish my big block for that.
If I rebuild the engine thats in the truck, then the truck would be down. I havent driven it 3 weeks anyways, fuel pump is going out.
Uploaded picture of my truck..
|03-26-2013 06:38 PM|
|vht||I wouldn't throw a set of heads on the 350 without going through it 1st. If I was going to use the 350, I would consider a 383. That would give you a little more torq for towing and you could still get decent mileage. The BB will out pull and out run the SB but the 1 I done for the same reason as you are sure liked the gas. Towing or not.|
|03-26-2013 10:45 AM|
Honestly I have seen much more luck on the trucks with high mileage to just long block it with a computer friendly cam. those can be done for reasonable from my re-builder..Of course most of those are work trucks that need to get back on the road for the guy to make some money with..
|03-26-2013 10:18 AM|
I am 3rd owner of the truck and the previus owner only put 28k miles on it in 6 years. I have put 2700 miles on it in 6 months. Mostly hwy road trips.. I am not looking to build a street strip truck. Just want plenty of tq to pull the race car or make the truck scoot when I want.
I just hate to get it all ready for H/C/I swap, then tear my 350 top end off to find worn cylinders or something.. I know many of people who do H/C/I on motors with over 130k miles. Mostly cars like Mustangs or Camaros, sure they get beat on more then my truck. My truck is also heavier..
Other weird issue is the engine temp never gets above 140 degrees. It takes hours of running to get it that warm. I have replaced so much stuff on this engine to work out the bugs, at one point i was just fed up with the 350 so I started building the BB. I can always save the BB for my race car project..
|03-26-2013 10:02 AM|
I went through that decision process on my truck and have decided to just freshen the motor I have since it works fine the way it is..Of course it is no tire burner but it chases parts just fine and pulls the car trailer OK. Save my money for other things is what I am doing. Of course this is just my opinion..
|03-26-2013 09:38 AM|
Opinions needed on BBC swap vs upgrades for 350
I had been busy building a roller block .030 454.. Everything has been machined for the bigblock. After much testing the flow of my Bowtie heads, the pressure drop from the intake manifold runner to the head runner kills power production from 2400 to 3900 rpm. Its almost equal at 80hp and tq drop and then it starts to climb right back up once above 3800rpm.. Needless to say heads are just too big..
How we got the numbers was, having the heads flowed on a bench and using 3 desktop dyno simulators with head flow data and engine specs.. Each simulator shows pretty much the same thing except the Dyno 2000 inflates the tq number by 5 to 10% over the other two programs. So i need a smaller runner intake on the heads. My plans are aluminum heads , also means I need another set of pistons with a dome to compensate for 118cc chamber of most other aftermarket bbc heads.
This motor was going to go into My ext cab 1994 Chevy truck. I have everything for the BBC swap as far as accessory brackets and what not. Currently truck is Stock TBI 350 engine(roller block) and healthy built 4l60e trans, 14 bolt semi floater 3.73 gears.Truck has some issues with fuel pump and the throttle body. I think the TBI unit is worn out and I gotta upgrade the fuel pump either way. Was going to go mild BBC to have that TQ to get this thing moving. Its my daily commuter. About 10 to 15 miles a day is all its driven.
After a few discussions with my friend while doing a head and cam swap on his race car, he was asking me why not just head and cam swap my stock TBI 350 engine with 167k miles? I am not sure its even got that many miles on it. Block is nice and clean black paint but the heads have no paint on them. Looks like the heads have been atleast gone through already and the driver side head has leaking valve seals on #3 cylinder. Not much if any smoke comes out and compression test shows me the rings are still good.
I looked into the idea of good set of Aluminum heads and a computer friendly roller cam with new intake for the 350. All the dyno numbers completely surprised me on the parts upgrades . 416 HP at 5500rpm and 444 tq at 3800rpm with a nice almost flat tq curve from 2500 up. That took me a while trying all different types of hydraulic roller cams before I found one that has about what I am looking for. Its the XFI252 comp cam.. No stall needed and computer friendly.. I really wanted a cam to make some noise, but my main goal is good strong tq production. Most other roller cams kill the power figures under 3500 rpm..
I have a megasquirtII controler and harness, plus most of the stuff needed to go mpfi. This was my plan for the big block, seeing as how its way more cash to make the TBI system capable of supporting this kinda power for either engine... I can use the MSII on either engine.
Now let me ask u guys, would anyone here be comfortable with putting aluminum heads, roller cam and intake on a motor that might have 167K miles? I have done it on motors with less then 100k miles. I Wont know mileage for sure till I pull the heads. For less then $1400 I can do the upgrades on the 350. Where as I am still looking at another $2500 to finish the big block.
Sorry its long post, just wanted to lay it all out there..