327Heaven

.............a GM 383 crate engine.

Okay, during disassembly the 400 block was found to have a nice crack in the journal area

Now I'm looking at a 383 crate motor from the General. Anyone run one of these babies and can testify to it's real world performance?

I was thinking of adding an Edelbrock endurashine dual carb setup for some bling. Would I be leaving any performance on the table by going to dual carbs over a single four barrel?

TIA

jackson

NEW, MORE AFFORDABLE ... 400 blocks available. Dart recently released new iron "SHP" line ... afaik both 4 & 4 1/8 bore ... but only 350 main bearing. http://www.dartheads.com/products/a-...hp-blocks.html

Unless you can expertly tune & balance 2 carbs, probably best to stay with one.

73, Dark Blue 454

That's a pretty good deal! I'll have to keep that one in mind for my next project.

billla

The GMPP HT383 is a bit of an odd duck IMHO. Since it's a standard 4.00 bore, they use a 3.80 (vs. 3.75) stroke to get the CID. The crank is forged...but the pistons are hypereutectic. From my perspective the thing is a bit of an odd collection of parts. It's also not a great deal at around $4,500. I'm a big fan of the GMPP engines, but this isn't one I'd pick. Generally, the GMPP stuff is pretty close on claimed power output at the flywheel and with headers.

There are certainly other choices, many for less coin.

Do you have a budget in mind? How much power do you want to make?

CA-Legal-Vette

That's a prety good buy. Good 400 blocks are getting harder to find and by the time you finish with machining, you won't be much cheeper than this.

327Heaven

Budget around $6 - 7k and looking for 475hp/500tq. On paper, the HT383 or ZZ383 output falls short. Any suggestions?

gkull

Are any of your 400 parts like the crank/rods/pistons forged and worth using again? Are you heads worth using again?

billla

If that's your TOTAL budget (back in the framerails) is then you're going to need to be frugal and smart. It sounds like a lot of money...but money spends quick doing engines and as we move past 1.2 HP/CID we need to start buying the good stuff I'm assuming that we're talking about flywheel numbers here...

From an initial design perspective, I'd start with a late model roller-cam block and a forged rotating 383 rotating ***'y from SCAT or Eagle. Fairly agressive hydraulic roller reusing the stock spider, retainer and lifters (if possible) with 1.6 roller rockers. Top it with a GOOD set of 210cc heads to make around 10:1 CR, either a VERY good dual-plane or a mild single-plane intake and a 750CFM carb and large-tube headers. This is going to get you right into that ballpark and right in your budget. As an example, I did a quick run using the GMPP HOTCAM (not my cam choice, just for grins) and AFR 210 Competition heads and found 471HP@6000 RPM and 472TQ@4000 RPM. My DD runs are pretty decent indications as I've very carefully tuned my model and build my own .cam and .flw files. The cam choice is the crux of the biscuit and is based on many factors...which is why engine design is an iterative process.

There are certainly MANY other crate engine choices that will get you into that ballpark as well - faster, with less risk and almost certainly cheaper.

Gkull's got a great point about re-using what you've already got - many options based on what's there.

327Heaven

Not sure what vehicle the 400 came from but no forged parts. Just wanted the block for a new project. Was intending to use aftermarket heads like Trick Flows, AFR Eliminators, or Brodix in the 210-220 range. Although high hp/tq numbers are desired, a street driven engine without too much drama and high 11/low 12 sec. capability is needed. Interesting how some vendors hype up the ZZ383 to have peformance in that range.

Would still like to include the Edelbrock dual carb setup.

ratflinger

You should be able to do that in your budget. Myself I'd build a 396, more cubes & hp for no more $. Either start with a good, used 350 & have it clearanced or get a GMPP bare 383 block & have the clearances touched up. Use a Eagle stroker kit with the clearanced H-beam rods. Get the balanced kit, as Eagle does a good job balancing. If you get the GMPP block it's the modern design, so you can use std roller lifters instead of the link bars or non-rollers. It's a 1-piece rear seal, neutral balance so flex/flywheel & harmonics have to match. I wouldn't go over 200cfm on the heads, AFR 195s are about the perfect size for this engine. Since you stated your budget, it's easy to see that you aren't building a 7000+ rpm engine, so higher flow heads will gain you nothing.

You might save some $ by using a cast crank, but stay with the forged pistons stroker cut rods. Alum rockers are cost effective too.

With a nice alum headed engine, forget the bling. A clean engine compartment with natural alum components speaks for itself. Use the bling money for real world upgrades. JMHO, of course.

BLOCKMAN

One of the guy across from my shop has one the GM 383's in his truck and is not very impressed with the results and we have spent a day on triing to tune the engine in and it still seems to be a slug.

The SHP block is a good choice for the money and it will take the factory roooer set up and here is another link on those blocks and do a search on the SHP block as there is better prices on them then that.
http://speedtalk.com/forum/viewtopic.php?t=12112

ratflinger

Quick look on ebay shows about $1400, not bad at all. The GMPP block I started from is now over $1000. If I was building now I'd have a hard time saying no to the SHP block.

billla

Usually the "no replacement for displacement" holds true, but a 396 is a significantly more difficult build for a home builder as the clearances get far more interesting - and can get more expe$ive. For the extra 13 cubes, IMHO not worth the effort and dollars.

195cc would be on the small side for a 1.2HP 383 CID IMHO. Just right for one making around 1HP/CID or a bit more.

I'd consider a cast stroker crank to be marginal at this power level, even balanced.

Check with your shop, but I'd budget maybe $600+ for the block alone by the time it's ready to assemble depending on machine work. Many of these late-model blocks don't need all that much at this power level.

All just one guy's experience.

GeorgeS

Usually the "no replacement for displacement" holds true, but a 396 is a significantly more difficult build for a home builder as the clearances get far more interesting - and can get more expe$ive. For the extra 13 cubes, IMHO not worth the effort and dollars.

Billa, not to steal the thread but what is he were to go to 408CI instead of 383? Longer stroke, more CI, more HP... Couldn't you also bump the compression to 11:1 , use a good dual grind cam and still run pump gas?

63mako

If I was doing a build today I would seriously look at this. http://cgi.ebay.com/ebaymotors/SBC-3...QQcmdZViewItem
Seems like a good base for a motor and it comes disassembled so you or your machine shop can check everything and make sure all tolerances and correct assembly and balancing procedures are followed. This takes a factory roller cam, your choice of heads and you choice of rod length, piston dome size and stroke. All forged good parts. Check here for some street combos. www.ryanscarpage.50megs.com/combos1.html

ratflinger

Agreed - this looks like a deal, wish had been available a year ago.

421ci & AFR210 comps - damn!

63mako

Yeah, pretty sweet setup.

dstaley

I think that I'd be considering a big block if I was in your position. It's a lot cheaper ot make 500hp from a basic 454 than it is from a sub-400 CID engine, and they are more durable.

billla

Brief response is the more CID we put into a GEN I package the more complex the build gets - and complexity = cost.

As for tweaking DCR to allow a higher SCR, I don't follow that school of thought at all. At a build level of around 1HP/CID 1 point of compression is worth around 3% power increase, and while DCR is one aspect of engine design using it to offset a high SCR it does not lead to a "street-friendly" engine in my experience.

327Heaven

Thanks for all the comments fellas.

Think I'll stick to a forged 383 and take it from there. Maybe a short block from one of the reputable vendors and throw on my own top end. Looking for a strong running small block and have good street manners for stop and go traffic. I think 475hp/500tq is within reach.....if not close.

At my age simple is better