I would have to say a fuel injected, 421 or 434, with a intercooled supercharger...lets say 10-12 lbs of boost, and a light shot of nitrous to cool the charge. Something mild for a semi-daily driver making upwards of 750 horsepower with a torque band from hell. That would be my choice !!!
Later,
Joe

 

Callaway did build at least one and I think two. Don't know the details but remember reading about these cars years ago.

George

 

That's what I set out to do this time last year, build my idea of the Ultimate Street Small Block. Gkull, you don't need to fly up here, just check out my website, it details everything, and I'm always willing to share my experience with anyone thinking about building one, or who is building one. I've had several people come over to my house to check it out after seeing my website. A few from the forum too. 'Yedister' from the C4 and Aftermarket forum was over a few weeks ago checking it out, he's build an SBC 427/434 right now. I don't believe is trying to hide things or keep secrets. It's just a hobby. Although I do find is funny when I read or hear someone say their cam specs or something is a family secret, etc. It ain't like we're Winston Cup crew chiefs or something...

I wanted something totally streetable, reliable, yet unique and with alot of power, utilizing Winston Cup quality parts. My initial goal was 700hp/600tq, with a self-imposed redline of 7000 rpm.

The only constrant was that is be a small block.

I looked at all the blocks first, production, Bowtie, SBC 2 (2.2), and aftermarket blocks from Dart, World Products, Donovan, Rodeck, etc. All options were considered, and I considered the block to be of utmost importance, second only to the cylinder heads.

I was especially interested in building an SBC 427, especially after reading about Mark Steilow's SBC 427 '69 Camaro he used in the Hot Rod power tour. Plus '427' has a nice ring to it, especially in a Vette. Also, I liked the idea that externally, it is almost identical in size to a production 350, bolts right in, and most people would think it was a 350. Over 600hp, yet relaible enough to drive cross country over 5000 miles. Versatile enough for a daily driver, yet capable on road courses or the 1/4 mile.

I liked the thought of using an aluminum block, especially the SBC2 stuff. It's just totally trick, and there ain't many out on the streets. I spoke to several of the leading engine builders and they all advised against using the SBC 2 stuff on the street. Universally, they said the performance benefits at the street level were not worth the additonal costs (2x more than SBC stuff) and the reliability and parts selection wasn't there. The blocks, for instance, are cast and machined to be as light as possible, thus giving up some block strength and rigidity. Keep in mind the SBC2 stuff is expressly designed for NASCAR, where they only need to last 500-600 miles at a time. But again, they are trick and unique, definitely capable of inspiring conversations at the car shows.

Also, the engine builders I spoke with advised against aluminum blocks altogher, for a street engine at the power levels I wanted. Certainly, aluminum blocks are capable fo that kind of power though, look no further than the C5R.

I worked with Fast Times Motorworks, which is here in Chicago. They are one of the leading engine builders in the 'street legal' racing organizations, like NMCA/NSCA/NMRA, and are featured all the time on Hot Rod and Chevy High Performance. They build the engines for Chuck Samuels and Nick Scavo's cars, among others. Chuck was the first to break into the 6's and go over 200 mph in his class, as well as being the first to use turbo chargers in his class, and has won the Championship. Nick has been among the top in his class for years. Anyway, my point is these guys know what they're talking about, and in their class, they are well respected. They told me they have seen iron blocks make more power over aluminum blocks the majority of the time, among comparible engines. The reason being the blocks are more rigid and bores are more stable, increasing cylinder/ring seal. The only real benefit to aluminum being weight savings...

So I ruled out the SB2 stuff and the aluminum block.

Since I strongly considering an SBC 427 or 434, I started doing the math. The only real problem with building a SBC this big is that you inevitably end up with a poor rod/stroke ratio. While many debate the pro's and con's of running a longer rod in terms of power output, it is universially acknowledged that a poor rod/stroke ratio increases side thrust loading on the cylinder walls, increasing friction and cylinder wall/piston/ring wear as well as affecting how fast an engine rev's up.

So one of my first considerations was figuring out what the longest rod was I could run. I called JE, they are arguably the best piston manufacturer and the standard on upper echelons of racing, since piston pin location and block deck height were the primary variables once stroke was determined. Based upon my intended usage, and the possibility of N20 usage they gave me their minimum compression height recommendations based on both 9.035" and 9.325" deck heights. Figuring the minimum compression heights, and knowing that I had decided on a 4.0" stroke, I was able to determine the longest rud I could run for each deck height. The standard deck height block, even with the longest rod that would fit, would yield a poor rod/stroke ratio, someing in the low 1.4's if I remember correctly. I considered that unacceptable. Alternatively, with a 9.325" deck block, I could run 6.125" rods, and with a 4.0" stroke, end up with a 1.53 rod/stroke ratio. For comparison purposes, the very popular 5.7" rod 383 has a 1.52 rod/stroke ratio, so my SBC 427 would have a slightly better, and acceptable, ratio.

Going back to the block, I decided to go with something proven, yet that provided the upgraded features which would help this engine work well and be a powerful, yet reliable powerplant. I strongly considered the GM Rocket Block, since it is avalable from any GM dealer that carries GM Performance Parts, and having been designed expressly for racing, I knew it would be a solid foundation. Upon further research, I found out that Dart actually makes the Rocket Block for GM, and they also offer the block under their own Dart Iron Eagle name. The Iron Eagle and the Rocket Block are identical in every way, except the Iron Eagle is designed to be a wet or dry sump block, whereas the Rocket is offered as under two separate part numbers, depending on whether it is wet or dry sump. I planned on going with a wet sump intially, but since I wanted to add turbo's on the future felt the dry sump option might be nice for turbo lubrication and scavenging.

So I ordered the Dart Iron Eagle with billet steel splayed 4 bolt/stud mains, SBC 400 sized mains, Big block cam bearings, and a tall 9.325" deck height - to allow me to run the long 6.125" rods. This block is especially attractive if you really want to make a big SBC stroker because the pan rails are spread .800", .400" each side and the cam is raised .391" to clear the rods without needing a small base cam. A side benefit is you can run shorter pushrods, creating a lighter, yet stiffer valve train. The block also features thicker decks, bulkheads, cylinder walls, and main webs than any production of Bowtie block. This block is build to be stroked and to be abused.

I then started looking at bottom end components. Like I said I wanted something bullet-proof, using the best possible parts available. I looked at Crower, Cola, Callies, Lunati, LA Enterprises, Bryant, Modex, etc cranks. I decided on a Crower 4340 Billet Ultralight crank. It's completely overkill for my application, rated for 10,000+rpm. But the thing that sold me was that it only weighed 40 lbs, even though it had a 4.0" stroke, yet it sacrificed no strength. keep in mind that a production cast 3.48" 350 Chevy crank weighs about 58 lbs, a 18 lb rotating assembly weight savings. As I found out later on the dyno, I believe it is a key contributor to how fast the motor revs, as well as the engine's overall efficiency and power output.

Staying with Crower, I decided to use a set of their billet 4340 'Stroker" rods, in a 6.125" length. I also upgraded to their 7/16" ARP Custom Age 625+ rod bolts rated at 285,000 psi, the absolute strongest rod bolt available anywhere. The rods are rated at over 10,000 rpm as well, while only weighing 518 grams.

With the block, crank, and rods selected, the next component, and the most important, to chose were the cylinder heads. I looked at all the SBC cylidner head options - 23*, 18*, 15*, 14*, 13*, splayed, canted, and SBC 2. Considering flow, availability, and parts compatability, I decided on the 18* head design. The other designs flow about 5% more at very high valve lifts, .650"+, but typically lose some low and mid lift flow, but have exhaust flow almost identical to the 18* heads. I looked at GM Performance 18* heads, AFR 18* heads, Chapman ported 18* heads, even some 18* heads from NASCAR shops. I decided on the Dart CNC ported 18* heads, because at the valve lifts I wanted to focus on (under .600") they were among the best, and the availability was good. They flow up to 355/260 cfm out of the box, but most importantly their low-mid lift flow was better than most small port 23* heads. As a matter of fact, at .400" they flow more than most 23* heads max out at. Even with 254cc intake ports, they are very efficient at low valve lifts, and offer amazing throttle response. Jeff at Fast Times commented several time how good and surprised he was at the the throttle reponse. The dyno sheets prove the low end performance.

I completed the heads with titanium Del West intake valves, retainers and locks. I used Del West Inconel exhaust valves to handle the heat if I decide to spray or turbo charge it in the future. Jesel 1.7/1.6 J2K shaft mounted roller rockers and double 1.55" PSI valvesprings topped them off. Those brands aren't too common on the street, but they are almost universally used in racing, and offered the best durability/relaibility. ARP 2000 fasteners were used exclusively on the valvetrain.

So with the heads selected, I could now order the pistons. Not only do you need to know the valve angle, but you need to know the valve spacing across the bore when you order custom pistons for a non-standard application like this. I ordered 10 JE psitons, 1 extra piston for each cylinder bank, with a set of their best Pro Max pins. I sealed the bores with a set of the tried and true, as well as universally accepted SpeedPro Moly file fit rings. In my opinion, alot of street guys fall victim to the advertising and use gapless rings. Look around and see what the racers and top engine builder, at any level, use and almost without exception it's SpeedPro Moly file fits. I ended up with a static compression of 11.27. Even with straight 92 octane pump gas, detonation/pinging has never been detected, either audibly or via a knock sensor.

I used coated Clevite 77 H-series SBC 400 main bearings, coated Clevite 77 rod bearings, and coated Durabond BBC cam bearings. Holding it all together is a custom ARP main stud kit. Unfortunately, ARP didn't make a main-stud kit for this block at the time, so I had to order each stud, bolt, nut and washer individually. The studs are longer than a standard block, due to the bollet caps, as well as the fact the the rear cap uses 1/2" studs. ARP now offers this kit after I did the R/D for them, and they didn't even give me a discount...bastards ;).

Although I wasn't going to use a dry sump at this point, I wanted a bullet proof oiling system. I chose a billet Pro Series Titan dual georotor oil pump with an integrated 14 square inch pickup. It alleviates the cavitation found in all spur gear wet sump oil pumps. I also had Stef's Fabrications make me a custom sheetmetal aluminum oil pan to fit the wide pan rails. It utilizes all of the wet sump tricks - kicked out side, integrated teflon coated uni-directional windage screen, scraper, and assorted baffles and trap doors.

Getting into the good stuff. I ordered 3 custom Comp mechanical roller camshafts. I tested different cams on the dyno to find the best combo. I ended up using a custom Comp mech roller with 256/264, .690"/.650" on a 112 LSA, installed at a 110 ICA. Unfortunately, there weren't very many SBC 427's at this power level out there in which I could use to help determine the optimum cam specs. So I did my own testing and research. For relaibility and weight saving reasons, I used a set of Nascar Jesel roller lifters. I also spent a considerable amount of time setting up the valvetrain for optimum rocker stand height, rocker to valve contact, and custom pushrod length - assembling, cehcking with Dyekem, disassembling, adjsuting reassembling, etc. I then ordered a set of custom double tapered, 210*, 7/16" CV Products pushrods.

I also decided to use an external, dry Jesel timing belt. This made cam changes and cam timing adjustment easier on the dyno, while freeing up a pony or two, and looking trick. I put an aluminum ATI Superdamper, MSD billet aluminum crank trigger and a Nascar Stewart Stage 4 aluminum high volume water pump in front of the motor. I completed it with a set of CV Products billet aluminum serpentine pulleys and brackets, in custom sizes and ratios.

To top off the motor, I orderd a custom Hogan's Racing Manifolds aluminum sheetmetal intake manifold, woth custom oversized fuel rails, 50# low resitance Holley injectors, and a TPIS 1300cfm Monoblade EFI thottle body. I'm controlling it via a SpeedPro sequential EFI unit with individual cylinder fuel and timing control. Every fastener on the motor is ARP, and all teh external fasters are ARP stainless 12 point for that trick look. All plumbing uses Aeroquip stainless hose and AN fittings.

I recently also had a set of 2" to 2 1/8" stepped tube headers made to fit the 18* heads, tall deck block, 82 Vette chassis, and to tie into a set of custom made sidepipes behind repor chrome '69 sidepipe covers.

As I mentioned, the motor was build for NO2, but I haven't set it up for it yet. I may not either, since I'm going turbo next year.

Gkull, asked me what I would do differently. I would've set it up for turbo's from the onset. I'm adding turbo's next year, I should have just done it from the start - gone with a lower CR (8.5-9.0) and an appropriate cam. I think I could easily make a reliable 1000hp/1000tq with some moderate boost. Other than that, I have no regrets. I would like to try it with a EFI converted Victor JR type manifold, so I can compare the Hogan's to it. It's possible that ude to the front mounted EFI throttle body, and the subsequent 90* degree turn from the plenum to the runners, that I'm giving up some power compared to a single plane style manifold which his a straighter shot into the heads.

But nevertheless, thus far it has been an impressive motor. On straight pump gas, it made 650 hp at 6700rpm and 580 ft lbs at 5100 rpm. However, most impressively in my opinion, is the fact that itmade 500+ ft lbs from 3000-7000 rpm. A flat, fat, streetable torque curve. Although I fell a little short of my intitial 700hp/600tq goal, I think I'm closer to that goal now. On the dyno I was forced to use smaller, more restrictive 1 3/4" stepped headers, which almost certainly sotme some mid-high rpm hp and tq. So i'm pretty confident that with the larger 2" to 2 1/8" stepped headers I'm using on the car, I'm closer to my initial goal.

I've only had it on the street a couple of times, since I just got my headers done. But so far it runs great, has never over heated ( it runs 190F in 90F air temp in traffic). The reliability test is still undetermined, but consdiering the parts I've used, the only weak link I can think of would be the valvesprings, due to the .690" lift, although PSI is the choice among the pro's.



[Modified by Monty, 2:44 PM 9/9/2001]

 

450 hp frpm a small block, sign me up.

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