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Project822
Project822 New Reader
8/27/21 1:42 p.m.

As this discussion moves on, I'm starting to think stock-ish bottom end but with floating wrist pins, good heads with good head work, SEM (probably Edelbrock after I read about numerous reliability problems with the Holley Sniper,) and a mild-ish cam and be happy around 350HP.

Strokers are super neat, but it's starting to look like unnecessary added expense considering the purpose of the vehicle.  

bobzilla
bobzilla MegaDork
8/27/21 2:02 p.m.

The bottom end on my truck engine is stock-ish. Just a parts house OE crank kit, stock rods/pistons with a decent cam and aluminum heads. 

Project822
Project822 New Reader
8/27/21 2:43 p.m.
bobzilla said:

You can get an easy 300-350 with Vortec heads, decent pistons and cam for under $2k. You can roll the dice on Chinesium heads like I did for the truck, and you'll need more cam than I have for sure. 

If it was me.... I'd do a nice clean roller block vortec headed 350 with a .480 lift cam and enjoy doubling the power ofthat Astro. 

That's similar to what I am starting to think also, although I would probably go to some aluminum hi-po Vortec replacement heads for improved flow and cooling.  Although I could start out with stock Vortec heads (if the existing ones with the engine I find are good) and upgrade later.  What I have to do first is internal engine stuff--because I do not want to pull that engine back out once it is in.  

AnthonyGS (Forum Supporter)
AnthonyGS (Forum Supporter) SuperDork
8/28/21 12:22 a.m.

So you aren't even going to look at what Lloyd Elliott can do with stock Gen 2 aluminum heads and a custom cam......   oh well.

 

 

 

eastsideTim
eastsideTim PowerDork
8/28/21 6:28 a.m.
bobzilla said:

You can get an easy 300-350 with Vortec heads, decent pistons and cam for under $2k. You can roll the dice on Chinesium heads like I did for the truck, and you'll need more cam than I have for sure. 

If it was me.... I'd do a nice clean roller block vortec headed 350 with a .480 lift cam and enjoy doubling the power ofthat Astro. 

I'm sure I'll be vigorously corrected if I am wrong, but that 300-350 HP range seems to be the transition point where a street SBC(hydraulic roller valve train, smooth idle, decent vacuum at idle, long life) starts to hit the point where it matches the cost of an LS swap.  So, that makes it a good target HP range if you want to stay gen 1.

bobzilla
bobzilla MegaDork
8/28/21 6:53 a.m.

In reply to eastsideTim :

If you started with a vortec truck engine and did a basic rebuild with a bigger cam you're not talking a lot of cash. Even going .030 overbore pistons are still cheap, crank kits with bearings are cheap. The most expensive part of that build would be cam and machine work. If you have a good machinist with reasonable prices you'd be in it for well under a grand.

bobzilla
bobzilla MegaDork
8/28/21 7:12 a.m.

Also here are the heads I purchased for the farm truck: 

edit: old link is dead. newest version a bit more pricey: https://www.ebay.com/itm/183156534972?hash=item2aa4faeebc:g:Jj0AAOSwIjVawDOq

 

759NRNG
759NRNG UberDork
8/28/21 6:46 p.m.

Small Block Chevy Should Have Built (purplesagetradingpost.com) 

As far as SBC's are concerned for a NA on 87 pump gas this would be my go to bullet...late

Project822
Project822 New Reader
8/30/21 7:08 a.m.
AnthonyGS (Forum Supporter) said:

So you aren't even going to look at what Lloyd Elliott can do with stock Gen 2 aluminum heads and a custom cam......   oh well.

 

 

 

That's an unusual way to try to say something helpful.  Let me repeat that I am brand new to SBC engines, and that means unaware of the names and deeds of people who have developed SBCs.  

Project822
Project822 New Reader
8/30/21 7:22 a.m.
bobzilla said:

In reply to eastsideTim :

If you started with a vortec truck engine and did a basic rebuild with a bigger cam you're not talking a lot of cash. Even going .030 overbore pistons are still cheap, crank kits with bearings are cheap. The most expensive part of that build would be cam and machine work. If you have a good machinist with reasonable prices you'd be in it for well under a grand.

That's definitely an option, and one that makes a lot of sense given the purpose of the vehicle.  I come from the world of sub 2.0L engines with old technology.  I am accustomed to have to throw every trick at an engine to make even a small improvement in power.  I am not used to the effect of (comparatively) large displacement and the effect even small changes have on power output.  

Stock rebuild with overbore pistons (might as well) with floating wrist pins (I'm used to having this and don't want to give it up,) a decent cam, some porting and better/bigger valves on the head, and I'm probably making plenty enough power for the Astro to be quick enough for me.  

Project822
Project822 New Reader
8/30/21 7:30 a.m.

I spoke with a friend about this engine over the weekend (also a member here) who got me thinking about possibly using a carburetor instead of the Edelbrock Pro-Flo.  He cautioned me about reliability concerns with the Pro-Flo.  From what I have read, the Holley Sniper TB system is out of the question for lack of reliability.  

This might be a topic for another thread, but what are your opinions about an appropriately sized aftermarket carburetor (Edelbrock or Holley +/-500CFM) on a street driven vehicle that must run well in all seasons, start undramatically, idle well in traffic, and generally behave well?

Project822
Project822 New Reader
8/30/21 8:03 a.m.
bobzilla said:

Also here are the heads I purchased for the farm truck: 

edit: old link is dead. newest version a bit more pricey: https://www.ebay.com/itm/183156534972?hash=item2aa4faeebc:g:Jj0AAOSwIjVawDOq

 

Very interesting.  Do you DD your truck?  Does the engine keep a good temperature?  How long/how many miles have you driven these heads?

03Panther
03Panther UltraDork
8/30/21 8:03 a.m.

With the stated desires for the use of the van, the peak numbers are just bragging rights, and not really relevant, IMHO. 
A very mild 350 vortec build, stock or aftermarket heads will shock you with the difference in torque compared to stock 4.3! No need to have deep pockets, or reinvent the wheel. wink

Im a huge Astro van fan, since the '80s when they were first coming out. Had a nice 92 in the mid to late '90s, and was wanting to do the same as you - towing, reliability, seat of the pants fun and bragging rights. Several astros through the years, and had a LT1 / 6mt waiting, but never made it sad

For what you want, if the mild build 350 doesn't bring enough smiles per mile, do the same mild top in on a 383 bottom end. Harder to find the non high end crank kits, but they can be had, and since you are not spinning it to the stratosphere, during a hard 1/4 mile, you do not need 4 bolt mains or the best forgings ever made. Keep it mild, use a good sounding cam, even at risk of leaving a bit of power on the tablesurprise

Beleive me, you'll be happy!

Project822
Project822 New Reader
8/30/21 8:06 a.m.
759NRNG said:

Small Block Chevy Should Have Built (purplesagetradingpost.com) 

As far as SBC's are concerned for a NA on 87 pump gas this would be my go to bullet...late

That's a pretty neat build, and I agree in principle with everything said in the article, but I think it is more involved than I want to get into for this van.  

03Panther
03Panther UltraDork
8/30/21 8:11 a.m.

The 500 edelbrock would be a bit small even for a fairly mild 350... and that's from a guy that does not like to over carb stuff, like 99% of the internet does! 
However the edelbrock, while being behind a holly style carb for all out HP. Is a great choice for a DD. The Q-jet is hands down the best street carb for drivability, performance and dependability. 
But the stock throttle body swap in place of the throttle body V6 has been a proven thing. Again I never completed one, but the road is well paved! And would be my choice for your Van.  

03Panther
03Panther UltraDork
8/30/21 8:12 a.m.

Where ya from? I'm in Lower Alabam', and would be glad to help, if you happen to be down this way!

SkinnyG (Forum Supporter)
SkinnyG (Forum Supporter) UberDork
8/30/21 8:37 a.m.

A carb can work quite fine in all seasons, you just need to take the time to tune it (much like EFI, though your hands will smell like gas more frequently).

My daily is a '77 C10 with a 350 and a Rochester Q-Jet, 11:1 compression and a snotty cam (108° lobe separation). The tighter the lobe separation, the stronger the torque at the expense of idle (yay) and maybe some top end (whoop-de-do).

Do a 350 (or 383 if you have the cash), re-use the accessory drive off the 4.3 if it works (I think it should?), keep the cam mild enough that you don't need to change the torque converter or gears or get radical in fueling and ignition and can still use pump gas.

My mantra for building my vehicles is "You're 300 miles north of Gimli Manitoba, and you need a ________. Where are you going to get that?" If you can build with largely OEM parts, you can fix it anywhere.

03Panther
03Panther UltraDork
8/30/21 9:09 a.m.

In reply to SkinnyG (Forum Supporter) :

I love a well tuned Q-jet! The got the Quadra-bog name from folks that didn't understand them. I wish I had the touch (and ear) to get them right, cause all the go to guys for me are all dead now. 
I can get a edelbrock (long as ya start with the right size) close enough to run about the same, all year long. 
I can get a Holly style carb tuned in a bit better. But the slightest bit of change in the weather, and I gotta re tune it! Don't care for em on the street. Love 'em for 1/4 mile! 
Never played with any aftermarket efi...

Project822
Project822 New Reader
8/30/21 9:15 a.m.
03Panther said:

Where ya from? I'm in Lower Alabam', and would be glad to help, if you happen to be down this way!

I appreciate the offer very much.  I'm in central Ohio, a bit too far I think. 

Project822
Project822 New Reader
8/30/21 9:27 a.m.
SkinnyG (Forum Supporter) said:

A carb can work quite fine in all seasons, you just need to take the time to tune it (much like EFI, though your hands will smell like gas more frequently).

My daily is a '77 C10 with a 350 and a Rochester Q-Jet, 11:1 compression and a snotty cam (108° lobe separation). The tighter the lobe separation, the stronger the torque at the expense of idle (yay) and maybe some top end (whoop-de-do).

Do a 350 (or 383 if you have the cash), re-use the accessory drive off the 4.3 if it works (I think it should?), keep the cam mild enough that you don't need to change the torque converter or gears or get radical in fueling and ignition and can still use pump gas.

The complete 4.3 accessory drive system fits directly onto the SBC.  The Astro is supposedly one of the easiest vehicles to V8 swap.

Project822
Project822 New Reader
8/30/21 9:32 a.m.
03Panther said:

In reply to SkinnyG (Forum Supporter) :

I love a well tuned Q-jet! The got the Quadra-bog name from folks that didn't understand them. 

I don't disagree.  But the Q-Jet has a reputation for being difficult to tune beyond stock engine, and I have very little carb tuning experience to leverage.  If I don't have to sacrifice drivability, I would rather work with something that is easier to tune.  I'm not stupid, but I have very little time to become a wizard with a carburetor.

Project822
Project822 New Reader
8/30/21 9:37 a.m.
03Panther said:

The 500 edelbrock would be a bit small even for a fairly mild 350... and that's from a guy that does not like to over carb stuff, like 99% of the internet does! 
However the edelbrock, while being behind a holly style carb for all out HP. Is a great choice for a DD. The Q-jet is hands down the best street carb for drivability, performance and dependability. 
But the stock throttle body swap in place of the throttle body V6 has been a proven thing. Again I never completed one, but the road is well paved! And would be my choice for your Van.  

My concern with the TBI swap, as easy as it would be on this TBI van, is that there is pretty much nowhere to go performance wise.  I could increase fuel pressure and chip it if chip makers still exist.  Beyond that, it's finished.  

What size carburetor do you think I should be looking at if not a 500?

03Panther
03Panther UltraDork
8/30/21 9:46 a.m.

Closest connection to OH I have is down near Nashville... still to far! 
the TBI still has more performance potential than the later CPI from late '90s on. I think a 454 TB and some readily available tuning, should cover your needs. Not the peak 450hp, but should cover actual needs. 

Project822
Project822 New Reader
8/30/21 9:53 a.m.
03Panther said:

Closest connection to OH I have is down near Nashville... still to far! 
the TBI still has more performance potential than the later CPI from late '90s on. I think a 454 TB and some readily available tuning, should cover your needs. Not the peak 450hp, but should cover actual needs. 

What I have read (not experienced) is that the 454 TB and injectors cause idling and low speed problems on a small block.  

06HHR (Forum Supporter)
06HHR (Forum Supporter) Dork
8/30/21 10:08 a.m.
03Panther said:

Closest connection to OH I have is down near Nashville... still to far! 
the TBI still has more performance potential than the later CPI from late '90s on. I think a 454 TB and some readily available tuning, should cover your needs. Not the peak 450hp, but should cover actual needs. 

This is actually the route i'm planning to take.  Replace my 350 with a 383, add a 454 TB for the added CFM and burn a chip so the computer doesn't freak out, a new chip will let the computer account for the extra CFM so no idle or low speed issues.  The thing I love about the stock TBI is it just flat works.  Rain, shine, 100 degrees or 10 below it just works. 

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