In 1990-91 Samantha Racings best performance was 7.89 seconds at the quarter mile, with a HEMI engine that was based on the original Chrysler Hemi concept, in the teams Dodge Daytona. This performance was at the expense of 5 totally destroyed engines.

As the breakage risk was very high even on this “record engine”, the team looked at converting the engine to the more developed Pro Stock engine technology. That meant increased bore, shorter stroke, lighter components as pistons, improved valve train, to name a few. And now a 10 year “science” project started. When we look back, we think it must have been a lot easier to have purchased the available components at the time, but first let us have a look at the facts:

1986 was the last year a 426 Hemi based engine was used in Pro Stock in the USA ( Reid Whisnant ). Our discret ( hmmm ) inquiries at HEMI/engine gurus like Dick Landy, Dick Maskin, Chrysler, the late “Grottis”, Bosse Redin among a few, shook their heads in disbelief, and we were labeled as morons. The B1 project was in the process at Chrysler for the next racing generation, where Wayne County and Jari Konola was doing development research. Companies like Indy Cylinder Head, Ray Barton and others haven’t started yet with their engine programs, so there weren’t any options getting a new engine block (expensive) to modify it for this project. But to have someone telling us that this is impossible, was the perfect motivator to start this project for a bunch of crazy small landers (really bad translation for smålänning= the area in Sweden where the team has their base) .  

3 used Keith Black engine blocks, together with heads was purchased, and rebuilt. The specifics were to rev the engine to 9500 rpm, with engine size of 500 cu.in.  For a blown engine 9.500 rpm might not be impressive, but it’s not that easy. The engine was christened “Elsa” and she got a 4.600 bore, which is a problem considering cylinder to cylinder spacing is 4.800 which means that cylinders were moved, 1 inch decked block, cut up side for better oil distribution, new mains, a really weird oil pan, cooling jacket on the outside of the block. This construction proved itself to be ok, but was modified when the next engine, named “Berit” was borne. 

"Elsa´s" crank shaft was a forged 440 Chrysler, that was welded and fabricated to get a high rpm racing touch, specially made pistons were ordered together with new conn.rods. The heads were prepared with nearly 13 lbs of welding thread, spark plugs, valves and  ports were moved, combustion chamber was welded and a new, intake with straight runners was made. The valve train was based on the original Chrysler Hemi engine, as well as valve covers and ignition wire caps. 

"Elsa" was used in our 91’ Dodge Daytona for 2 years, with absolutely no reliability. Parts were coming loose all over the place, and I said Elsa was like my wife, both makes a lot of noise and throw things all around. We made a couple of 7.90 runs with Elsa, but at a cost. Every workshop within a circumference of 100 miles around the Scandinavian racetracks had a visit from Samantha racing. All in all, we still wanted to develop the engine program, so the next step was to create “Berit”. 

One of the problems with”Elsa” was the cylinder sleeves wasn’t fixed in the block properly, and moved around too much. To try to solve this problem a new engine block was made, but we made 2 cylinder chunks from specially made engine block blend ( thanks Volvo and Flygt ) these chunks was assembled in the aluminium block and was secured. New billet heads was made, and they were milled in the in garage milling machine from 1951 ( no CNC, that’s not the “hard” way), a new intake, new valve covers, oil pan, rocker arms was manufactured, but the rocker stand was from “Elsa”. We also made changes to combustion chambers, valves and camshaft. 

”Berit” has been a visitor to the Scandinavian tracks as well, but due to conn rods breakage, cam shafts failure, rocker arms broke, and please, don’t mention push rods, the engine would never hold on for more than 200 feet at the time. We had a specially made sign put up on our trailer “Beware of flying HEMI parts”.Someone in the team once made the comment “those Chevy guys seem to have a good time” 

Give up!  No way, to actually get some more racing time instead of repairing, we bought a Pontiac engine. We instantly moparized it with Dodge valve covers. With Jesel rocker arms and oil in pushrods, the engine worked fine (the GM guys knew this all the time), but we still think that the valve covers made it tick. 

When ”Berit” was buried ”Bambam” saw the daylight, and for a Hemi freak this is a “masterpiece”, and a proof that if you put your mind to it, everything is possible. Bambam have his faults, but today after 10 years of development, the engine could be considered as a race engine. Specs are B1 cast iron block, 4.600 bore, and 3.750 stroke. We used the heads of Berit with rocker arms like Jesel. Lifters from Jesel instead of the titanium ones we made, 2.450 intake and 1.800 exhaust valves, together with a large lobe camshaft, gear changes at 9200 rpm and max rpm at 9500. We haven’t run the engine in bench, but have made 7.70 passes in our Dodge Avenger.

I will continue to tune ”Bambam”, because I am still convinced that this engine could produce the power to reach 7.30-7.40 et:s. If Chrysler didn’t start their own Pro Stock Hemi, maybe my ideas could have been interesting with the current available racing parts. However, this project have been fun and we learnt a lot, making our “own” engine. If we would have mentioned all of the hiccups, strange people, and brain storming ideas following this project, we would have needed to write a book.

We hope that all of you race fans have enjoyed reading about this project.

Mikael Sjökvist

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Hemimotorn