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-   -   1996-2000 vortec block build (http://www.hotrodders.com/forum/1996-2000-vortec-block-build-225979.html)

ss396si 11-11-2012 05:23 PM

1996-2000 vortec block build
 
i have a STREET car 69 chevelle,1975 305,(29-3200 stall convertor) th400, and 3.73 rear.
I am on a budget, looking to put a 350 in with up to 400hp and torque. The late model vortec engines have a stronger bottom end than the earlier style engines.
Now, I dont have to get the motor to my hp and torque goals right away. At this point, I want that 305 out of my car. So Im looking to just put the motor in with a stronger bottom end. Then down the road change the top end.I can transfer parts from the 305 to this motor. My question is will a 1996-2000 vortec engine, be the right choice for a good foundation? Finding a remanufactered long block should be easy.
Also does it have mechanical fuel pump provisions?

vinniekq2 11-11-2012 06:19 PM

almost any 350 can make 400 hp/torque

ss396si 11-11-2012 06:39 PM

is a vortec engine a smarter reliable move? Will it support 400hp/tq without overly stressing the internals. I want to know if this motor is better as oppose to a goodwrench 350 for my goal.

ap72 11-11-2012 07:00 PM

Any good 350 short block should be able to handle 400hp/tq. If you can I would try to get a block with roller cam provisions, 4 bolt mains, and flat top pistons. Those three things will give you a great set up to build a strong engine down the road. If you can I'd also spring for 6" rods, a nodular or cast steel crank, and the best balance job you can get. A high volume oil pump is a cheap upgrade and while it may not be absolutely needed, it's cheap insurance. If you can afford it forged pistons with a thin ductile iron or steel ring set are also great.

Getting all of the things I recommended will set you back a good amount, keep in mind there is a BIG difference between a run of the mill reman enigne and a top notch custom built engine.

Going cheap isn't a crime, but if you want to get something really nice I'd look for the things I mentioned. A 3.75" stroke may be a consideration too.

cdminter59 11-11-2012 10:09 PM

1996-2000 vortec block build
 
If you have a 1996-2000 vortec block, you will need a rotating assembly like this for a 355 cid rebuild. Eagle Street/Strip Kit, SB Chevy 350, 3.480' Eagle Crank, 5.7' Eagle Rods, 9.6:1 KB Pistons - SB Chevy 350 Assembly kits - Eagle Street\Strip Rotating Assembly Kits - Eagle Rotating Assembly Kits - Rotating Assemblies | CNC Motorsports | Car Parts | . This rotating assembly to rebuild as a 383 cid. Eagle Street/Strip Kit, SB Chevy 350/383(87-99), 3.750' Eagle Crank 'Internal Balance', 5.7' Eagle Rods, 9.7:1 KB Pistons - SB Chevy 383 Assembly kits - Eagle Street\Strip Rotating Assembly Kits - Eagle Rotating Assembly Kits - Rotating Assemblies | . If you don't have a 1996-2000 vortec block you can purchase a complete short block internally balanced with harmonic balancer and flexplate included. CNC Street Strip SB Chevy 383 Stroker Short block, 3.750 Crankshaft, 6.0' Rods, 9.7:1 KB Pistons - Small Block Chevy 383 Short Blocks - Short Blocks | CNC Motorsports | Car Parts | Truck Parts | Competition Engines. You can't go wrong with any of these kits. I wouldn't think about a goodwrench short block or long block compared to the shortblock sold here.

hpete 11-12-2012 01:25 PM

For your stated goals the vortec is a great choice. The crank and rods are strong enough and the pistons are fine if you can get the compression to fit your needs. If you can find one with 4 bolt mains (1 ton) that's better but 2 bolts will work fine.

oldbogie 11-12-2012 02:51 PM

Quote:

Originally Posted by ss396si (Post 1610071)
i have a STREET car 69 chevelle,1975 305,(29-3200 stall convertor) th400, and 3.73 rear.
I am on a budget, looking to put a 350 in with up to 400hp and torque. The late model vortec engines have a stronger bottom end than the earlier style engines.
Now, I dont have to get the motor to my hp and torque goals right away. At this point, I want that 305 out of my car. So Im looking to just put the motor in with a stronger bottom end. Then down the road change the top end.I can transfer parts from the 305 to this motor. My question is will a 1996-2000 vortec engine, be the right choice for a good foundation? Finding a remanufactered long block should be easy.
Also does it have mechanical fuel pump provisions?

The Vortec is not fully machined for a mechanical fuel pump, it can be finished off however. The Vortec timing cover is plastic and does not accept changes to the OEM timing gears and chain without some effort. They can be backdated to a metal timing cover. The question gets to the cam whether you want to keep it a roller or convert back to a flat tappet.

The cylinder walls don't extend as deeply into the crankcase as older 350's which simplifies putting a stroker crank in there but also reduces some support for the piston skirt, this pretty much demands a hypereutectic casting or a VMS-75/4032 high silicon forging in order to minimize the skirt clearance so high accelerations from wide clearances can't happen when the thrust sides change at BDC.

I'm not impressed by GM's powder metal rod, I certainly wouldn't use it for any high performance application.

It seems you have a pretty high stall converter is this because the 305 is running a big cam? A 350 running Vortec heads, Performer RPM intake, Holly of 650 to 750 CFM, a Comp XE 268 or any of the aftermarket equals to these can easily get to 370 hp and with some tuning, porting, 1.6 rockers, big tube headers and certainly a 750 cfm carb will go to 400 or so. Piston choice plays big on the low through middle high RPM power. A D-dish or flat top piston in-place of the OEM round dish piston for a common compression ratio of 9.5 to 1 and holding the squish/quench dimension to not more than .040 really wakes up the middle RPM ranges with as much as 20-30 foot pounds of torque and 10-20 horses. The round dish piston output converges on the D-dish or flat top at peak RPM but under that the better piston really carries the day with a fatter power curve. This curve also carries a slightly higher power peak at a bit higher RPM with a slower decay than seen with the round dish piston.

Bogie

ss396si 11-12-2012 03:09 PM

Quote:

Originally Posted by oldbogie (Post 1610402)
The Vortec is not fully machined for a mechanical fuel pump, it can be finished off however. The Vortec timing cover is plastic and does not accept changes to the OEM timing gears and chain without some effort. They can be backdated to a metal timing cover. The question gets to the cam whether you want to keep it a roller or convert back to a flat tappet.

The cylinder walls don't extend as deeply into the crankcase as older 350's which simplifies putting a stroker crank in there but also reduces some support for the piston skirt, this pretty much demands a hypereutectic casting or a VMS-75/4032 high silicon forging in order to minimize the skirt clearance so high accelerations from wide clearances can't happen when the thrust sides change at BDC.

I'm not impressed by GM's powder metal rod, I certainly wouldn't use it for any high performance application.

It seems you have a pretty high stall converter is this because the 305 is running a big cam? A 350 running Vortec heads, Performer RPM intake, Holly of 650 to 750 CFM, a Comp XE 268 or any of the aftermarket equals to these can easily get to 370 hp and with some tuning, porting, 1.6 rockers, big tube headers and certainly a 750 cfm carb will go to 400 or so. Piston choice plays big on the low through middle high RPM power. A D-dish or flat top piston in-place of the OEM round dish piston for a common compression ratio of 9.5 to 1 and holding the squish/quench dimension to not more than .040 really wakes up the middle RPM ranges with as much as 20-30 foot pounds of torque and 10-20 horses. The round dish piston output converges on the D-dish or flat top at peak RPM but under that the better piston really carries the day with a fatter power curve. This curve also carries a slightly higher power peak at a bit higher RPM with a slower decay than seen with the round dish piston.

Bogie

the reason why im running a high stall convertor is, at the time i was having my TH400 installed I wanted a wicked big block so that convertor was picked according to the engine by the trans company. years later, I've decided to just keep it a small block for driveability and price.

Hogg 11-15-2012 01:17 PM

You can get a 96-2002 2 bolt longblock for $2200 and a 96-2002 4 bolt L31 longblock for $100 more.

-Roller cam equipped
-forged Powdered metal rods(stronger than the old Pink rods)
-nodular iron crank

With the cam that comes in it, 191║/196║ 0.412"/0.428" 111║LSA expect around 310-320 gross hp.

Great beginning for a nice street engine.

peace
Hog

hcompton 11-15-2012 07:58 PM

I have seen some ppl make good power with the 305. But have you also called the local junk yards to see how much a LS motor would be with harness and cam. The larger bores can easily make 400 hp/tq 350 gen I or II will struggle to make the numbers for the mpg and power output. Also some small mods really can make them scream.

Other than that i would recomend a gen I 383. It will make the numbers needed to move a heavy car. Also very little cost over the std bore 350 rebuild. You cna buy a junk yard 350 and have it bored add the simple external balanced stroker kit and go. Also works with parts younhave and wont need different intake and heads. Some good regular heads and your good. Usally the after market rotating assembly is stronger than most stock stuff. Even with pmd rods. The cast cranks are fine for 400 hp range. No need to get forged or internally balanced.

techinspector1 11-15-2012 08:36 PM

Quote:

Originally Posted by ss396si (Post 1610071)
Then down the road change the top end.I can transfer parts from the 305 to this motor.

Be careful here. Bolting the 305 heads to a 350 block and using a short duration stock cam could raise the dynamic compression ratio into the threshold of detonation, depending on fuel quality. Resist any thoughts you may have of using two head gaskets to lower static compression ratio. That'll just make it worse.

ss396si 11-16-2012 05:25 AM

This would be my first 350 build. I would need a hoist, engine stand, and other tools. A crate engine might be a better choice for me. No guess work and you get a warranty. I'm thinking about the year one crate 350.

1Gary 11-16-2012 06:45 AM

Quote:

Originally Posted by ap72 (Post 1610114)
Any good 350 short block should be able to handle 400hp/tq. If you can I would try to get a block with roller cam provisions, 4 bolt mains, and flat top pistons. Those three things will give you a great set up to build a strong engine down the road. If you can I'd also spring for 6" rods, a nodular or cast steel crank, and the best balance job you can get. A high volume oil pump is a cheap upgrade and while it may not be absolutely needed, it's cheap insurance. If you can afford it forged pistons with a thin ductile iron or steel ring set are also great.

Getting all of the things I recommended will set you back a good amount, keep in mind there is a BIG difference between a run of the mill reman enigne and a top notch custom built engine.

Going cheap isn't a crime, but if you want to get something really nice I'd look for the things I mentioned. A 3.75" stroke may be a consideration too.

I'm with you until you get to the 6" rods and needing a 4 bolt main.Ring spacers because of pin placement and mm ring sizes for long mileage use on the street isn't what I would suggest.Two bolt blocks for street use at 400 hp would be fine.If later he wanted more,he could go the splayed mains which would be a much stronger part than a OEM 4 bolt.

1Gary 11-16-2012 07:17 AM

I don't think,given you saying the plan was for a BBC in the beginning,your ever going to be happy with any SBC.Sometimes your first gut feeling is the right one.And in this case I think your right.

Here is what I suggest you do before you spend the time and money on a SBC.Call Pat McCarthy of McCarthy Performance.Techinspector1 would agree with me he builds some of the most rightest BBC's at very reasonable prices.It is kind of his specialty.Do talk to Pat and if you like,tell him I told you to call.

McCarthy Performance / Racing Engines to 632+ Cubes

He'll build you a pretty shout SBC too if you like.

ap72 11-16-2012 08:25 AM

Quote:

Originally Posted by 1Gary (Post 1611869)
I'm with you until you get to the 6" rods and needing a 4 bolt main.Ring spacers because of pin placement and mm ring sizes for long mileage use on the street isn't what I would suggest.Two bolt blocks for street use at 400 hp would be fine.If later he wanted more,he could go the splayed mains which would be a much stronger part than a OEM 4 bolt.

If you're going splayed caps you may as well go SHP, a 4 bolt block can be had for the same price as a 2 bolt and it has added strength.

With a 3.48" stroke the support rings aren't needed, the 6" rod does require support rails on the oil ring with a 3.75" stroke, which is no problem and common for some engines, the pistons should be bought for metric rings so spacers are not required.


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