Parts Combo For My Chevy 383 Stroker Engine 460+ HP

The parts list for building the 383 stroker engine for my 79 Corvette has now almost come to its final state. I must say that choosing the right parts has really been a pain because there’s just so much to choose from and every part needs to be Googled and checked through the forums. My friend Jim Barth from Salt Lake City, USA has given me a lot of help to build this 383 stroker and a lot of credits will go to him once the engine actually fires up. I certainly recommend him to anyone who wants to build a powerful 350 or 383 or any other Chevy engine.

SHORT BLOCK

Now here we go… first of all the short block. I took the original Corvette L-48 2-bolt main SBC 350 block out of my car and cleaned it up and removed all the original parts. The block was showing the usual wear on the cylinder walls and no factory honing marks were present anymore. It was as shiny as a mirror and also remarkably wider than it should have been originally – caused by the pistons over the years. Fortunately no big damages so I have sent the block to an engine shop where they will bore the original 4.0 inch cylinders over by 0.030 inches which will make the cylinder bore 4.030 inches – the proper bore for a Chevy 383 stroker engine. SCAT 383 Stroker KitThey will take care of the block and will also deck the cylinder head surfaces on the block by around 0.02 inches to make them straight and even and clean of all the old gasket remains etc. The important question now is what to put inside the short block – talking about the crankshaft, rods and pistons. The easiest way was to get a fine stroker kit which already contains all the important parts. I decided to go for the SCAT 383 stroker kit, already internally balanced in the factory with the included parts. The kit also contains forged pistons, the crankshaft is cast metal. The problem here in Estonia is that nobody properly balances a V8 engine and that’s why the safest way for me was to get an already balanced rotating assembly kit. In addition to the main components the package also contains piston rings, ARP rod bolts, oil rings, main bearings and a few other important components. What the kit doesn’t contain are the main cap bolts which hold the crankshaft in place – for these I have also decided to go with ARP’s. I’m yet to decide whether to get the standard strong bolts or studs.

The next important thing is ofcourse the camshaft. First of all, one needs to decide whether to go for hydraulic flat tappet (the factory standard for First-Gen small blocks), hydraulic roller lifters or solid roller lifters. I will write another article on the difference between them just to make it understandable also for the beginners (like I was a few months ago). However, since the hydraulic roller kit is 2-3 times more expensive than flat tappet and gives perhaps about 20-30 hp extra in my setup, I have opted for the hydraulic flat tappet solution this time. I can always convert to hydraulic roller set-up in a couple of years when I feel I need the extra power.Comp Cams Kit When choosing the camshaft you need to consider the intake duration and exhaust duration at 0.050 inch lift. You also need to think about the valve lifts and lobe separation. It all depends on the components you choose and cannot be explained in one paragraph – it’s always easier to ask people’s advice in the forums like Hotrodders, Chevelles.com and Corvette Forum. In my scenario the perfect camshaft would be the COMP Cams Xtreme Energy 230/236 camshaft with grind number CS XE274H-10. When deciding on the valve lift the cam provides you need to consider the max. valve lift available on the particular cylinder heads you get. With AFR heads it’s 0.690 inches and the hyd flat tappet only lifts to 0.490. Plenty of room there and the AFR would actually feel more comfortable with hydraulic roller cams which lift the valves more. The 230/236 camshaft also provides the nice choppy idle while giving enough vacuum out of the engine to power the brakes and suck enough vacuum into the reservoir found on the 79 Corvette to lift and close the headlights. The particular kit from Summit comes with the Comp Cams lifters and double roller timing chain and gears.

Another thing to replace inside the block is the oil pump. After doing the research in the forums I’ve figured out that Melling makes the best budget pumps. For such engine it’s also important to get the high output version. There are stories that Melling’s pumps used to be good in the old days but a few years ago they changed their castings to cut on costs and this resulted in cracked and malfunctioning pumps. People still say that they’ve recently gotten rid of these issues and these pumps are anyway the best to get.

Melling Oil Pump SBC

All the bolts on the short block as well as the rest of the engine should be replaced with better ones, preferrably ARP produced bolts.

LONG BLOCK

Now the long block part which means everything above the block itself – cylinder heads and intake. I have decided to go with the Air Flow Research AFR 195 cc Street Eliminator aluminum heads which are pretty much the best on the market today for such an engine. They do cost more than the Trick Flows and even more than budget stuff like Darts, Edelbrock lower end aluminums, Patriots and such. The AFR’s produce more horsepower and torque in the end so the extra few hundred bucks might be well worth it. The AFR heads also allow for 0.690 inch valve lift so they are perfect with hydraulic roller camshafts to get the maximum out of the heads. The valves on them are 2.02 intake and 1.6 exhaust. AFR SBC 195 headsThese AFR heads already come CNC ported from the factory and there are people who port them even better to achieve the maximum performance. But note – when choosing the heads you need to check on the intake chamber size – 195 cc is the optimum for a street 383 stroker engine and 180 cc is better if you build a 350 or 355. The larger these chambers the more low end torque you sacrifice to achieve more horsepower in higher RPM’s. That’s cool if you go to the strip. But on the street you don’t want to keep the revs up all the time. That’s where the lower cc heads come into play. The 195 cc heads are perfect for a street 383 performance engine to provide the best of both sides – lower RPM torque and 6000+ RPM horsepower. Another factor on cylinder heads is their flow. This is different – the better the heads flow the more power you get in the end since the heads won’t be limiting the fuel mixture getting into the cylinders. That’s where many of the cheaper heads lack the good numbers. When buying cylinder heads it’s possible to get them in bare configuration or factory assembled. Bare means that you only get the heads and none of the springs, valves and other stuff that need to be on them, too. Assembled heads come with valves, springs and installed valve stem seals. Everything is assembled already for you and you just have to bolt them onto your block. This is the better solution in most cases unless you want to go with some specific components. Assembled heads are often cheaper than to order the stuff and assemble them all by yourself.

The hydraulic lifters come in the camshaft kit from COMP Cams. The lifters need to drive the valves on the cylinder heads and there you need to get a set of new pushrods. Jim Barth recommended the Trick Flow 4130 chrome moly pushrods which retail in Summit for about 120 bucks for a set of 16. You can ofcourse also buy new rocker arms but I believe I will stick to the factory ones since I won’t be revving the engine too much and the roller rocker arms are still very expensive. These are easy to replace items at a later time so I better leave these for the future.

To get the most out of the Chevy 383 stroker engine you should get a fine intake manifold to complement the great heads. Edelbrock produces pretty good aluminum manifolds and they can be bought for fair prices. Edelbrock Performer RPM intake is a good one although the Performer RPM Air Gap is even better. I couldn’t get the Air Gap because it’s even higher and won’t leave enough hood clearance with the 79 Corvette.

At this point I’m leaving the repaired Rochester Q-Jet 750 cfm carburetor on and I will get an electric choke add-on for it. I will also leave the factory HEI distributor in its place. Since the new engine will be revving a lot better than factory and there’s a danger to over-rev it and cause damage, it’s the best to get a rev-limited distributor. If you stick to your stock HEI like I will, you can get a special RPM limiter module from MSD or other ignition system producers. Better be safe than sorry, you know.

I am still about to decide what kind of flywheel to get since I’m building it for the 4-speed Super T-10 manual transmission at this point. I will write another article about it soon when I have gotten some more information and won’t be telling lies to you. Since my engine will be internally balanced, I need to get the harmonic balancer and flywheel to be zero-balance. The harmonic balancer will be probably SCAT Powerforce Series 8000.

balancer sca-d-80020_w

I will soon write some more articles – first of all some clarifications about different camshaft and lifter set-ups and once I have the proper information, I will also tell you about the flywheel choice.

Need To Decide What Cylinder Heads To Buy For My SBC 350

We’ve been having a discussion in the Corvette Forum on my engine project and it’s now a fact I need to get some aluminum cylinder heads to complement the rest of the engine. I ofcourse want the best ones, but I need to stay within a budget. I’m trying to acquire a pair of assembled cylinder heads for around 1200 bucks. They can be slightly used but they must be a good brand. Can be Dart, but I prefer AFR. An important factor choosing the heads is the intake chamber volume rating which needs to be around 180-200 cc in my case. The larger engine you have or the more HP you want at high RPM, the larger cc you need. However, in my case I don’t want to RPM too high (just around 6000-6500) and the engine is 350 and maybe 383 later in a year or two. When I get too big chambers like 230 cc or so, I will donate a lot of the low end torque which is important when driving on the street and perhaps not gain that much extra HP since I won’t rev it very high.

Click here to read the Corvette Forum post

Corvette Engine Bay Photos After Painting and Chevy 350 Block

As promised, here are the photos of the Corvette engine bay I just took in my garage. As you can see, the engine bay has been cleaned and repainted. We did spray-painting there since I’m no good with paintguns and didn’t want to try my luck. We applied two coats of black metal primer, then two (three in some areas) coats of gloss black metal paint and finally two coats of semi-gloss varnish. The results can be seen in the photos below. I also attached photos of the engine as it’s almost fully apart and before cleaning the block. The block was so dirty outside it looks like a diesel tractor engine from old times. I have now almost cleaned it and it will be washed by specialists, too. Then I will paint it orange, I guess :)

What’s the Status with My Corvette Right Now?

I thought I should give an update about the Corvette, specifically the current status of the ongoing project. As you might already know, I’m restoring the engine compartment and rebuilding the engine, adding more power at the same time. The engine and the transmission are off the car, the engine bay has been taken into pieces so most of the stuff has been removed for cleaning and repainting the surfaces. The engine is currently sitting on the engine stand and everything except the crankshaft are off the block. What we found out was that a couple of the pistons were considerably damaged! There were pieces off from the lower sides of the piston skirts and a few other pistons had cracks in the same areas. The possible causes for these issues are most likely worn piston rings and cylinders, resulting in piston slap. The cylinders didn’t have remarkable damage although they need to be drilled and honed which will make the engine a 355.

Am I still planning the stroker? Actually, no. I am hoping to get away with the old crankshaft since my goal is a street car with 400-500 hp under the hood and the 350 cid engine is perfectly capable for that. I don’t want to put a fortune on the engine – I want to build it well and out of pieces suitable for the particular setup, not a complete overkill. I ran the possible future engine through a software called Engine Analyzer and I should be able to get 350-380 hp out of it when leaving the cylinder heads to be the same (58cc heads from Chevy 305). The compression ratio is 10.8:1 and the camshaft will most likely be from Comp Cams bought in a kit with the chain and hydraulic roller lifters. Since the roller lifters actually need a specific block to make them work, I will need to install a retro-fit kit which is still a mystery for me but I’ll find out about it in the near future.

Next week I’ll try to send the block for drilling once I know where to actually send it. There should be a place here in Tallinn but I might also have to send it to Finland instead. I hope the block ends up fine and they won’t find any cracks in it.

I will post images of the engine compartment within the next few days.

Stroker Kits: Differences Between Forged and Cast

I’m currently in the middle of building my 79 Corvette 350 Chevy engine more powerful. Considerably more powerful – before it put out just about 250 hp or so. I’m looking to get at least 350 hp out of it. Hence I shall build a 383 Stroker out of it and need to get a stroker kit. So here I am now – the engine taken almost completely apart and the parts I’m going to use for the 2013 driving season are:

  • 79 Corvette original 350 cid 2-bolt engine block
  • Edelbrock Performer RPM Quadra-jet Edition intake manifold
  • Rochester Quadra-Jet 850 CFM carburetor, rebuilt. I might replace this but not sure yet.
  • OK quality tested 58 cc factory GM heads from a 305 cid engine, ported; currently stock 350 head valves, but might install larger ones
  • Hooker Headers ceramic full length headers

SCAT 383 Stroker KitI’ve decided to build a 383 stroker out of this engine and now I’m deciding which stroker kit (also called rotating kit in Summit catalog etc or rotating assembly) to get. I’m going to limit my budget somewhat and get the components I need, not what’s the best of the best. I still want to get the best for the buck. First of all I need to decide whether to get forged pistons and crank, just forged pistons and cast crankshaft or hypereutectic pistons and cast crankshaft. At first it might seem that whenever you have the money, go for the most expensive stroker kit – everything forged. However, that doesn’t seem to be the case. It’s not just about what’s more expensive, it’s again about what you’re going to build. It’s quite simple with the crankshaft – forged is stronger and can live with more hp and RPM than the cast version. Still, professionals say that forged steel crankshafts belong to the racing world – a street machine rarely needs one. It’s a bit more complicated with the pistons. I’ve done some research and these are the main things to know about what pistons to get when buying your stroker kit:

FORGED PISTONS

  • ligher in weight  – less stress on rods and crankshaft
  • absorb / dissipate more heat, therefore better for power adders like turbo and nitrous
  • expand more with heat, need more clearance in the bore
  • due to extra bore clearance needed, they rock in the bores more than cast pistons and cause quicker wear for piston rings and other components
  • more ductile
  • much more tolerant in detonation conditions
  • more expensive (although not too much!)
  • detonation can cause holes melting into pistons
  • also better in case of higher compression ratio
  • softer and wear out quicker than cast

HYPEREUTECTIC PISTONS (CAST)

  • do not expand that much with heat, therefore tighter bore clearance is acceptable
  • smaller wear on piston rings and other components due to less rocking in the bores
  • more affordable
  • detonation and other harsh conditions could make them crack – more serious for the engine than melting!
  • harder material, therefore in good conditions they last longer than forged pistons

As you can see, both pistons have their own advantages and disadvantages. It is said that whatever you put into your engine, it’s crucial to use good oil and change it once it gets too muddy. Also a lot of importance is put on the connecting rods – it’s better when they are made of forged steel. Then they will stay round for longer and again, are simply more resistant in harsh conditions and won’t bust so easily.

Another question is – what manufacturer’s stroker kit to get?

Talking about the budget stroker kits, there are two main producers  – SCAT and Eagle. After going through lots of topics in the forums people seem to consider SCAT components as better ones than Eagle. However, there are plenty of happy Eagle users around. Personally I’m thinking of getting a Scat stroker kit since that’s what most people seem to be prefer. I’m no expert yet and I better listen to the opinions of the professionals around.

It’s also very important to have the crankshaft balanced well. You can buy an already internally balanced stroker kit and it seems to be around 200-300 dollars more expensive than the non-balanced one. People still say that even if you get the balanced crankshaft, it should be still checked. They also say that for example Eagle non-balanced kits rarely need any mallory added and they are almost identical when they come out of the factory.

So, at the moment I’m still in the decision phase but I’m quite sure the stroker kit will be as follows – SCAT made, forged pistons and rods, cast crankshaft.