1930 Studebaker Indy car projec

[PackardV8]

I've got a friend who's building a replica of a 1930 Studebaker Indy car with a 250" straight eight flathead and he's ask for some help. I know you can't grind air, but has is there enough lobe material that anyone ever done this century's higher intensity, higher lift lobe profiles for a flathead engine? A straight eight would require a loooong billet to make a cam from scratch, but ever heard of that being done?

The stock 250" engine timing is 15° / 49° for intake, 54°/ 10° exhaust with .343" lift. Reportedly, the factory Indy cars with the 337" straight 8 used 8°/52° on the intake and 40°/20° exhaust. Given this is a 3-1/16" bore x 4-1/4" stroke, it's probably not going to want to turn much above 4,000 RPMs.

Theoretically, what would happen if an OHV .400" lobe lift profile were run in a flathead, sans rocker ratio? It would have .400" lobe lift, but assuming it doesn't run off the edge of the lifter, does it work at all? Since there's less mass in the valvetrain than an OHV, should a flathead look to use something similar to what today's OHC engines are running? The OHC RPM range is probably wrong, but flatheads turn similar to diesels, so what's the same/different in valve motion?

[wyrmrider]

HIJACK
what size is the lifter, is it flat or curved, is it a mushroom? and what dia is the base circle- for starters

[Carnut1]

20150603_180711.jpg

Not apples to apples but might help. When I reworking this Willys Hurricane the few cams available ran outside the rpm this design could handle. What I choose to work on was airflow through the engine at stock lifts. 30 degree Vizard style intake valve seat, standard 45 degree 3 angle exhaust. Careful porting due to thin bowls. I was able to find aftermarket stainless valves and springs and a header. Thanks, Charlie

[pdq67]

20150603_180711.jpg

Not apples to apples but might help. When I reworking this Willys Hurricane the few cams available ran outside the rpm this design could handle. What I choose to work on was airflow through the engine at stock lifts. 30 degree Vizard style intake valve seat, standard 45 degree 3 angle exhaust. Careful porting due to thin bowls. I was able to find aftermarket stainless valves and springs and a header. Thanks, Charlie

The 2nd '52 Willys Areo Eagle 2-dr/ht car I had way back in the later '60's had a 6-banger Hurricane engine in it! Quite the odd-ball little engine if I do say. And the little USPS mail carrier Jeep engine I really like is the old SOHC Tornado engine with the 6-lobe cam...

My 1st Willys Areo Eagle 2-dr/ht back in the mid '60's had a flat-head, 6-banger in it that I couldn't get .040" under mains and inserts for so it was in the trunk when I got the car. I put a '51, 232" Stude V-8, 3-speed stick OD in it to play with. I moved the front cross member back to the 4-banger position and the V-8 just kinda dropped right in...

pdq67

[mk e]

I've got a friend who's building a replica of a 1930 Studebaker Indy car with a 250" straight eight flathead and he's ask for some help. I know you can't grind air, but has is there enough lobe material that anyone ever done this century's higher intensity, higher lift lobe profiles for a flathead engine? A straight eight would require a loooong billet to make a cam from scratch, but ever heard of that being done?

2 thoughts.
You can grind air.....once it's replaced with weld. Web cams does a very big business welding up lobes and grinding whatever you want. The last I knew the price was about $100/lobe, not economical for s SBC project, but way cheaper than starting from scratch on a oddball engine. I've used and have many friends who've used them many times over the years with no problem.

On billet...I don't think the length really matters all that much. When I did the billets for my frankenferrari v12 we just worked near the chuck and kept sliding the billet out journal by journal. There was a little run-out because of that, but we left meat for grinding and it worked out fine....other than its 48 lobes at $100/lob to get them heat-treats, straightened and ground

[mk e]

Theoretically, what would happen if an OHV .400" lobe lift profile were run in a flathead, sans rocker ratio? It would have .400" lobe lift, but assuming it doesn't run off the edge of the lifter, does it work at all? Since there's less mass in the valvetrain than an OHV, should a flathead look to use something similar to what today's OHC engines are running? The OHC RPM range is probably wrong, but flatheads turn similar to diesels, so what's the same/different in valve motion?

Forgot this piece. I used to play with Indian motorcycles and the hot cam was always a shunk.

http://www.ebay.com/itm/Indian-Cam-Lobe ... 2291551665

...the kr750 H-D stuff is more modern so maybe look at that?

[PackardV8]

I used to play with Indian motorcycles and the hot cam was always a shunk.

I've only fiddled with one Indian, and IIRC, it was a flathead, but it had roller lifters.

[mk e]

I used to play with Indian motorcycles and the hot cam was always a shunk.

I've only fiddled with one Indian, and IIRC, it was a flathead, but it had roller lifters.

As does the H-D kr...I forgot that minor little detail.

Still the timing is probably close to what you want.

How many crank jounals does the engine have? A lot of stuff from that time had 1/2 what modern designs have and the cranks move around a LOT and that is really what sets the redline.....but this might not apply to the one you're working on.

[PackardV8]

How many crank jounals does the engine have? A lot of stuff from that time had 1/2 what modern designs have and the cranks move around a LOT and that is really what sets the redline.....but this might not apply to the one you're working on.

Not a problem here. It has nine main bearings to hold only 250".

[CamKing]

just got done making some 44" billet steel cams for one of the OEM's. We machine the billet, and rough in the lobes on the CNC, but the programming charge would be too expensive for a one-off project like this. If you wanted to have one turned on a lathe, I could walk you thru it. To rough in the lobes, heat treat, and finish grind, you'd be looking at under $1k