Here's a look at block prep for the 1927 Fast Four Dodge. Note the upper and lower girdles and external support struts to help strengthen the assembly. Lifter gallery features homemade rev kit with small block Chevy components. Earlier versions used studs and nuts with original main caps to retain the crank.
"Ditching the babbitt and fitting modern hardback bearings was my next task," says Tony as if this were a matter of fact task. Babbitt is a fine bearing material, and it might have been able to support the cylinder pressures and associated bearing loads that this motor would experience but he didn't want to risk it. The bearing catalog was consulted and it was determined that due to the hefty wall thickness of the stock main inserts no off-the-shelf bearing would be a direct fit. Bearing shell spacers, like those used when destroking a Chevy 400 with a 350 crank, would be required. Starting with a bar of cored bronze (bronze was chosen so that the thrust bearing surfaces could be made as an integral part of the #3 bearing spacer) Tony machined spacers for each main bore and then split them in half. The block was line bored twice: once to straighten and make the main bores perfectly round, and then a second time with the spacers installed to set the ID for Clevite bearings from a modern industrial application. Spacer halves were numbered, directionally marked, and labeled for top or bottom position.
In subsequent years the stock main caps were replaced by a solid steel 2" thick bedplate. It ties the entire bottom end of the block together and is the anchor point for external fasteners that provide additional support for the head. The steel was waterjet cut from a plate based on Tony's CAD drawing and then he finish machined it.
Only one of the stock Fast Four cam bores actually has a bearing, a babbitted bronze insert with integral thrust bearing. The other four run in the block's iron. Quite a few modern engines have a cam bearing arrangement similar to this but Tony didn't want to leave anything to chance. The bearing book was consulted again, and suitable ones from a big Cummins application were chosen. The block was line bored to accept these bearings, and individual bearings were narrowed on the lathe to work in the different width cam bores.
The stock head has combustion chambers the size of a man's fist, generating a lowly compression ratio of 4:1. Short of expensive welding Tony could see no good way to make the kind of compression he wanted using the stock head. Fortunately crew member Chris had crewed at Bonneville for a fellow that makes aluminum heads, Earl Edgerton (EDGY Speed Shop). He agreed to cast us a head (and bet Pete $100 that he couldn't get a car on the Salt in one year, but that's a whole different story). They pooled their ideas regarding combustion chamber design and Chris went to work. He took the stock head and created the desired combustion chamber shape using Bondo. Then he did it again because only two of the chambers are the same shape - the other two are mirror images. Earl took it from there, making a wooden pattern and having the aluminum head cast from it.
The Fast Four has a stock bore of 3.875 just like a 283 Chevy but the pin diameter and compression height of the two engines are very different. It was determined that the stock rods were not up to the task of handling the anticipated power levels so custom rods were ordered from Crower. The rods were designed around stock 283 pistons (hypereutectic flat-tops with 4 valve reliefs) and Clevite rod bearings from a different industrial application.
To put the pistons at zero deck required a very long 9.375" center-to-center length, but resulted in a favorable rod ratio. An engineer at CP Pistons saw a Hot Rod article on the car, along with the picture of the pistons. He knew he could do better and contacted them with a lighter yet stronger design featuring less drag, better ring sealing, and no valve reliefs. Not long after that they picked up CP/Carrillo as a sponsor and have had the pleasure of running their custom pistons and rods ever since. To ensure proper piston fit and optimum ring sealing a homemade torque plate was made from a large chunk of aluminum to facilitate torque plate honing.
The stock Fast Four cam and generator were both driven by a chain. Since they were eliminating the front cover and the generator a suitable replacement was needed. After taking some measurements on the cam and crank it was determined that 340 Chrysler timing gears could be fitted with some machining. Tony turned the noses of the crank and cam down , and cut keyways in both to work with a gear drive. "I mounted the idler to the new front motor plate fabbed out of 3/8" steel plate." Gear backlash adjustment is made via a t-nut that slides in a slot in the motor plate.
Cylinder sleeves, bronze guides, and oversized hardened valve seats were installed. The stock cam and lifters were sent to Earl Edgerton for regrinding. To get a decent amount of lift lots of material needed to be removed from the base circle. This lowered the lifters in the block so longer adjusters were needed. Tony made his own. "I started with grade 8 bolts, faced the heads in the lathe, case hardened them in my wood stove using Kasenit, quenched them in oil, then tempered the shanks. I wasn't absolutely sure it would work, but 6 years later we're still using the same adjusters."
Pressurized oiling required much better sealing at the front and rear of the crank. In stock form the rear main "seal" consists of a felt wiper that only covers half of the hole in the back of the block! "With the stock crank I was restricted to the existing seal journal so I made a seal holder to fit in place of the felt wiper and packed old school rope seal in it and a recess in the oil pan. That worked well enough to run, but it never really sealed. Once we were able to upgrade to a billet crank I spec'd it with a SBC rear main seal journal and machined a two piece seal holder. No more rear main leaks."
"The front main sealing was much easier to handle. When I was turning the nose of the crank for the Mopar timing gear, it was a simple matter to make it work with a Mopar damper as well. Then I incorporated the corresponding front main seal into the fabbed timing cover."
"Finding off-the-shelf valves proved to be a bit of a challenge due to the very long valve length used in the Fast Four (about 6 1/2" overall length). Tractors and industrial engines are nearly the only place that you'll find valves of that length, but those applications aren't really focused on making power. I did finally find modern race engine valves of a suitable length but I had to use exhaust valves because the intake valves had much too large of a head. Bought 8 used ones off of Ebay for $48 - not bad! Cheap and readily available SBC springs, retainers, and keepers were employed. Spring installed height was achieved by machining custom spring spacers."
Fast Four distributors are cast from pot metal and are very fragile so when you do actually find a Fast Four engine it's extremely rare to find an intact distributor with it. Rather than try and adapt one from a different application we opted for a crank trigger ignition. It's a waste spark MSD system meant for midget racing. A universal timing wheel and trigger mounts were modified to work on the motor.
Adapting the motor to a modern drivetrain was the next task. Getting a flywheel on was relatively simple as the Fast Four was very similar to a SBC flywheel bolt pattern and register diameter, requiring only minimal machine work. Adapting a SBC bellhousing required more work though. Chris made an adapter plate out of 1/2" thick steel and bolted it to the block. Dowels in the block locate the plate. The bellhousing was set on the adapter plate and a dial indicator used to perfectly align the bellhousing centerline with the crank centerline. Once that was done, the bellhousing alignment dowels were welded into place in the adapter plate and the bolt hole pattern drilled and tapped.
Over the years we've tried several different intake schemes: 4-bbl NA large volume plenum, 4-bbl NA small volume plenum, dual side draft, and 4-bbl blown) and two different exhaust schemes. All of these required fabbing different manifolds and headers which Pete handled deftly. Starting with waterjet cut flanges and raw tubes he cuts, pieces, and welds everything together. Our latest intake was fabbed out of aluminum and put together with the assistance of a friend and local custom bicycle frame builder, Carl Strong.
Pete was also responsible for designing and fabbing everything related to the blower mounting, driving, and plumbing. For the first couple of years we ran NOS copper laminate head gaskets. These worked remarkable well but we did have some issues, mostly due to the stock gasket's poor fit to our custom head. With calipers, ARP head studs, and specially machined alignment dowels I took several hundred measurements on the head and block to get the precise position and shape of the combustion chambers, head studs, valves, bores, and coolant passages. Using that info I made a CAD drawing, printed out full size paper 'gaskets', and fine tuned the design until everything was right. The final drawing was sent to a custom gasket maker.
After switching to the blown classes we suffered a couple of catastrophic engine failures (the deck was torn off the block in both instances). It was determined that a better way of holding the head on was needed. Compared to modern blocks, these old castings were very thin when they were new, and after 80+ years they haven't gotten any thicker. There is simply not enough material in the block's deck and sides to support the combustion pressure that we're now making. To remedy this, fasteners are run externally from bosses on the bedplate and motor plates up through a 1" thick steel 'sandwich plate' on top of the head.
So far the Montana Dodge boys have knocked off ten SCTA speed records using core hot rodding skills and the determination to fabricate whatever was not available. Their effort evolved from a bench racing conversation to a multiple record holding team; strong testament not only to their collective hot rodding and fabrication skills, but also the fundamental concept of the internal combustion engine and its ability to produce more and more power as knowledgeable hot rodders continue to tweak and massage it far beyond its original design. Besides the records, perhaps the best part of this enduring project is the statement these guys make about the valve of traditional hot rodding skills and motivation. There is no substitute.
10 Time Bonneville SCTA Speed Record Holder
1928 Dodge Roadster w/ Fast Four Flathead 4-Cyl.
Vintage 4-Culinder Flathead Class Records
V4F/STR, 109.962 MPH Street Roadster
V4F/STR, 115.681 MPH Street Roadster
V4F/GR, 116.439 MPH Gas Roadster
V4F/FR, 117.597 MPH Fuel Roadster
V4F/BSTR, 127.352 MPH Blown Street Roadster
V4F/BGMR, 130.843 Blown Gas Modified Roadster
V4F/BGMR, 142.956 MPH Blown Gas Modified Roadster
V4F/BGR, 138.395 MPH Blown Gas Roadster
V4F/BFMR, 143.254 MPH Blown Fuel Modified Roadster
V4F/BFR, 138.984 MPH Blown Fuel Roadster
FAST FOUR BUILD SHEET
|Stock, modified for full pressure oiling, main and cam bores line bored, sleeved, decked, ported
|Melling, 3.875" bore
|Moldex custom, 4.500" stroke, fully counterweighted, drilled for rod oiling
|CP custom, flattops, slipper skirt
|CP, SBC diameter, narrowed
|Total Seal custom, steel top ring, low tension oil ring
|Best Gasket custom
|Carrillo, custom billet, 9.375" length, full floating pins
|Integrated into one piece steel bedplate
|Clevite, Continental, narrowed & chamfered, oil holes drilled to match block
|Main Bearing Shims
|Custom machined, line bored in place
|Durabond, Cummins, narrowed, oil holes drilled to match block
|Modified stock bearing
Custom billet, ground for reverse flow by Edgy Speed Shop, 280 duration, 0.440" lift
|Stock cores, reground by Edgy Speed Shop
|Custom machined, extended, made from ground and case hardened grade 8 fasteners
|Stock, shortened to work with higher lift cam
|Lifter Guide Retainers
|Solid steel, machined from bar stock
|Edgy, custom cast aluminum, chamber design by Chris King
|Small block Chevy
|Valve Spring Spacers
|Custom machined, steel
|Ferrea, Pontiac, 1.900", backcut, hand lapped
|Ferrea, Pontiac, 1.800", backcut, hand lapped
|Small block Chevy
|Small block Chevy
|340 Chrysler gear drive
|Custom fabbed, integral cam thrust button
|External, mounting and drive fabricated by Pedro
|Modified for external adjustability
|Stock, modified to work with bedplate, integrated windage tray and crank scraper
|Stock, modified for crankcase evacuation
|Custom fabbed by Pedro & Carl Strong
|MSD, SB Chrylser, modified to fit
|MSD Midget DIS
|340 Chrysler, fluid filled, modified to fit crank
|Blower Drive and Plumbing
|Custom designed and fabricated by Pedro
|Custom fabricated steel
|Custom fabbed by Pedro
Montana Dodge Boys
Lead Photo, Home Page Flipper and Closing Photo:
Michael Harrington, www.automotve-photography.net
Engine & Car Photos
Tony Smith and The Dodge Boys