Hi everybody I am interested in starting a conversation on building a 350 sbc from the ground up. I have read some articles and forums and mostly it seems to be an upgrade from an existing engine. And also most are concerned with that last bit of HP at the top end.

I would like to build a Budget 350 with a great torque curve for street driving. It will go infront of a M20 4sp and 3.08 rear gears.

Rules:
-Not a crate engine (I am young and want to learn and have the fun experience of building my own)
-Not a 383 ci
-Under or around $3000 canadian if possible.
-Lots of Torque, I am thinking around 400+, not too concerned with top end HP numbers.

So everyones opinions on short block components, heads, cam, intake, carb, headers is welcome and appreciated. Any combo, any list! Please include estimated torque and cost.

Thanks!

 

http://www.chevyhiperformance.com/te...ild/index.html


http://www.chevyhiperformance.com/te..._iv/index.html

http://www.popularhotrodding.com/fea...ine/index.html

This will get you started. Best bet is a roller block with vortec heads for power on the cheap.

 

 

Absolute best platform is a late-model L31 5.7L Vortec. Most of these are in amazingly decent shape - even at high milage - with very little bore wear, and in some cases a bottle brush hone, rings and bearings will take care of the shortblock. The heads can be a bit more problematic but a valve job with guides will still be less than new heads.

Go with a mild cam upgrade, intake and carb and you're golden. I've done a couple of these and have been very happy with the results. Get a decent, well-maintained one - it's worth looking around and pulling some valve covers. NOTE that this does require an electric fuel pump - something to consider.

Sadly, just about every GEN I out there is going to be junk - so although you can certainly do a low-cost rebuild and likely come in under your budget number, finding a good core can be a real challenge.

L31 applications:

• 1996–2003 Chevrolet Express/GMC Savana full-size vans
• 1996–1999 Chevrolet/GMC C/K full-size trucks
• 1996–1999 Chevrolet Suburban/GMC Suburban full-size long-wheelbase SUVs
• 1996–1999 Chevrolet Tahoe/GMC Yukon (and 2000 Tahoe Limited) full-size short-wheelbase SUVs
• 1999–2000 Cadillac Escalade

http://en.wikipedia.org/wiki/GM_Vortec_engine

 

63mako: What is the difference between a roller block and these "retrofit roller cams" that go in a gen1?

Also, I am a little concerned with the electronics on one of the newer style of motors. How hard is it to deal with that? Or are you saying to strip it all off and set it up as if it was a gen1?

I already have an edelbrock performer intake, so if I used vortecs I would need another intake. By the time I add that on it is close to a new pair of dart SHP. What are your thoughts on that?

 

If you want to stick with standard intake the Dart SHP 180 seems like a good option. Retro roller cams usually run a little more. The Howards Cams line at Summit is reasonably priced and billet steel core. Good USA made stuff cheap. A cast Scat rotating assembly (383 is actually the same cost as 350) This block is brand new and will take a 2 piece rear seal to internally balance.
http://www.jegs.com/i/GM-Performance...15#moreDetails
The money you save in machining an old block and the extra you will save using OEM roller type lifters and cam makes it a good deal.
Scat is a better product but the eagle rotating assembly is cheaper.
http://www.jegs.com/i/Eagle/356/B13402E/10002/-1
This cam is a match for the compression and charactristics your looking for.
http://www.summitracing.com/parts/HRS-183215-10/
Then the 180 64 cc heads
http://www.summitracing.com/parts/DRT-127122/
Then you have rockers, lifters, pushrods all the tin and fasteners. You will hit the torque numbers your looking for.

 

Many different ways to skin this particular cat - just be sure to run the numbers if you've got a hard budget

I'd add up the numbers of buying everything piecemeal very, very carefully as compared to going through an existing engine - especially a Vortec in decent shape. All of the electronics go, so there's no issues there at all. There's almost $3K in just parts...before all the other stuff you'll need...and no one should ever buy a NEW 3.48 stroke rotating ***'y.

I, and many others, won't use Eagle products given that they are often well out of tolerance.

Choose - and budget - wisely.

 

With Billa, many ways to do this and power cost money, especially if your rebuilding something used, need go fast parts and don't own a machine shop or the measuring and assembly tools you need. You can buy a brand new GM Performance vortec L31, 4 bolt main, complete long block for $2000 (Free shipping!). A new intake, carb, cam upgrade and fuel pump your still under your budget with about 350 HP 350 Tq and everything new with a 3 yr / 100,000 mile warrantee from GM.
http://www.jegs.com/i/GM+Performance...30283/10002/-1

 

I am not expert like a lot of the guys on here, but I just finished my first "non stock" engine build. What I can give you advise on is:

1. Whatever your budget is, you'll go over it.
2. Don't underestimate the costs of the little things you'll need to complete it, they add up quickly.
3. I found I get stuff locally much cheaper than the internet in a most cases (advance auto parts was cheaper than jegs/summit on everything I compared pricing on and could most of the same stuff).

I wanted to keep the "numbers matching" so I wanted to reuse the original block. My dad bought the vette brand new so I wanted to keep everything somewhat original-ish and have the ability to swap it back to original later without having to store a complete engine. Plus, building the engine is part of the fun!!

Everybody told me to get a crate engine, but it isn't what I wanted to do. I have no regrets I chose to rebuild it myself!!!

 

I like the idea of a brand new block, just gives nice peace of mind. Billa you mentioned never go with a new rotating ***’y, how would you go?
A couple rookie questions here; is a roller cam worth the extra money, and why? Also are the lifter bores different in a gen1 as compared to something that had a roller lifter in it in the first place? What differs from a retro fit roller to a “regular” roller?

Billa, you mentioned the L31 is the best platform, why is that the case? What would you say is a reasonable price for one in decent shape (I understand it can change a lot, but ball park figure)? After rebuilding it would it just be better to get that L31 crate for $2,000 that 63mako suggested? (I am willing to go for a crate engine if it means saving money over building/fixing one) Also are the engine mounts the same/will it fit in a vette?????

After reading plenty of forums (including a few posts by both of you) I just spent $750 last week for a new intake (edl2101), headers (hedman68280), cam and lifters(sum1103), Felpro 1094 head gaskets and some dress up pieces for my stock l48 to get it up and running better, hoping for 250hp, 300ft/lbs? I am leaving the stock heads and springs, just isn’t in the budget to upgrade those right now. So I am looking for a goal in mind to save up for.

I really appreciate your opinions guys!

Edit....LOL yes budget and cars don't belong in the same sentence, I understand that. I am with you there vetteonbeach, I would like to build my own, but on the other hand if there is a significant savings on a crate it throws a wrench into the equation eh?

 

The 1987 and up engines have provision for factory roller cam and the spyder that holds them and a one piece rear main. Same lifter bore. The L31 has the above, plus vortec heads. Motor mounts are the same, center bolt valvecovers, different intake. It will bolt right in . The one piece rear main engines are a hybrid balance, neutral front, externally balanced flex plate. I prefer internally balanced in a performance build but there are a lot of these running around doing just fine. You will need a different flywheel as the one piece bolt pattern is different and the flywheel is weighted for balance. A roller cam is always worth the extra especially if your building from scratch. More power with better vacumn and idle compared to a similar flat tappet @.050 duration and you can used any oil you want. Durability of the hydraulic rollers are awesome. My brother ran an L31 in his 3/4 ton chevy truck over 300,000 miles and it was never apart and still ran great when he sold it. That won't happen with a flat tappet cammed engine.

 

Good book.

 

[QUOTE=billla;1580772624]Many different ways to skin this particular
I, and many others, won't use Eagle products given that they are often well out of tolerance.

 

If you get a used engine. you then have to rebuild it. A basic rebuild will cost you 13-1500 bucks no matter what. Haven't seen it done right for less. Then you have to find and buy the rebuilable engine. The GM long block is done but needs a cam upgrade. You can reuse your headers and carb and sell your intake to help buy a new one. I would not use eagle stuff either, your budget limits what you can do.

 

If you re-read Billla's post carefully, you'll see that he doesn't say "no one should ever buy a rotating ***'y." He says "no one should ever buy a NEW 3.48 stroke rotating ***'y." What he means is, that since a new 3.75" stroke rotating ***'y is virtually the same price, it's not cost effective to buy the 3.48" stroke version.

I think that if you budget wisely, drive hard bargains, and stay away from dress-up, eye-wash stuff like chrome valve covers and billet aluminum air cleaners and other such non-sense, and do all the work yourself, you can build an engine cheaper than a crate engine, but if you figure in that your time and effort are worth something, it quickly starts to look like not such a good deal. The only good reason to build your own is if you want the experience of doing it, (unless you're building some sort of custom, all out racing engine) in which case, who's to say it's not worth it? It's gonna take awhile, with trips back and forth to the machine shop, and you're gonna need a place to do it, and a few special tools.

One of the "rebuilding chevy small blocks" type books might go a long way toward answering a lot of your questions, and provide a solid base of knowledge before you start cracking open an engine.


Keep the shiny side up!
Scott

 

This is probably the best price you will find anywhere for a fully machined L31 roller block ready to build. Considering a junk yard core is $100 and your average machine shop costs can run $800 for comparable work, this is a bargain.

http://www.summitracing.com/parts/SUM-150100/?rtype=10

 

OK, let's take a couple of steps back on a few things There's a lot of great information flying around on the thread, and I think there's a little confusion on a few things.

First, the observation regarding rotating ***'ys is simply that if you're buying a crank - buy a 383 crank. There's no reason not to build a 383, period.

A roller lifter bore is exactly the same as a flat-tappet cam bore - the difference is that flat-tappet cams rotate as they move, and - a roller lifter cannot be allowed to rotate. A roller-cam block has the components built-in to do this, aftermarket retrofit rollers don't - and so cost far more. The key point is that factory roller components are 100% reusable...so you save a ton of money buying a used engine over buying a bare block.

The L31 is a great pick because the longblock is a very sound foundation - the heads are some of the best Tier 1 heads out there, and with the right cam will easily make stump-puller torque and >= 1 HP/CID at the crank

Regarding overhaul of a Vortec, doing a re-ring and bearings on a GEN I SBC is sheerest fantasy. Folks do it for sure, but the bore and crank wear is such that it's just not reasonable. However, Vortec engines are a different deal completely. Using fuel injection and fed a steady diet of synthetic oil, every one of these I've torn down has had virtually zero bore wear and negligibable (at worst, near the high limit of the spec) crank wear. I've done a few of these were I've done the "old skool" bottle-brush hone, rings, bearings and go...which is dirt cheap. This approach is usually a "hack" and I'd avoid it...but it works quite well with these FI/synthetic oil engines. A full overhaul is almost certainly not required...but certainly surprises happen Cost varys dramatically by area - a few phone calls will tell you what you need. It will bolt right in with the right flywheel and an electric fuel pump.

If you've got an existing L48 that's healthy, not 100% sure what you're looking for in a new engine unless it's just the experience as noted.

You specifically noted in your original post you wanted the experience of rebuilding and so didn't want a crate - if you do, there are lots of great choices including the L31 short/long block and many others. It becomes a question of budget A crate is about a wash with doing a full rebuild of an SBC of any generation...but it's a predictable (fixed) cost vs. the "surprises" that can come up during an overhaul.

And there are certainly ways to do a very low cost but still quite reliable and quality overhaul.

I think that's everything

 

One of the reasons I am hesitant to go for a crate engine is that shipping for me is going to be $1000 from summit! And a crate from my local engine builder is over $4000 before tax.

What are peoples opinions on finding a low mile L31, and simply doing a cam and intake/exhaust swap with no rebuild? Worth it, not worth it? Good idea, stupid idea?

 

Your location doesn't show - but check with your local Chevy dealer regarding one of their crate engines. You'll pay more than for an online store...but often there is no shipping, especially if a) you're willing to wait for a regular parts shipment and b) the dealer will provide trade price, which they'll sometimes do if you make it easy for them (payment in advance, no pick-up issues, have the P/N, etc.).

If you get a decent L31 you can absolutely run it "as is" if it's at < 100,000 miles and well cared-for.

 

Build one for yourself. When you have questions just ask on here. You'll get a feel for the answers you like best.
There is a great satsifaction in building your own engine. You'll have a better understanding of how it works that will benefit you in the future.
It's a skill that is being lost to some extent these days. Many more folks built their own engines in the past that do these days I feel.
Just don't hesitate to ask when you have questions. Look up the 383 a guy built with help from this site not long ago. I don't think you'll be as involved as he was, but there was some good and some so so information on that thread.