291 DeSoto hemi on the dyno today, fired for the first time VIDEO

Went to Bischoff Engine Service today to watch my 291 get fired for the first time. Pretty nervous watching it, but it should be able to be tuned out pretty nicely. Here's a little background on it. It started life as an S22 291 Fire Dome. I wanted a mean street setup so I went to Bischoff Engine Service (www.besracing.com) to have the work done. They have many records and hemi experience under their belts, so I knew it was in good hands. The bore is now 3.800 inch, up from the 3.71875, making it a 303 now with Ross slugs checking in at 10.5:1 compression after CC'ing the chambers. The cam was a custom design from Donnie Johansen from the famed Howard's cams. It's a solid roller, .520 lift, 272 duration at .050, not a ton of lift but a LOT of duration and Isky 3/8" pushrods were used. 330 heads were used and port work was done to blend the seats and port match the Weiand 4x2 manifold to the heads. Rocker Arms were taken care of by Rocker Arm Specialist who did a GREAT job on them. Custom fabbed 1 3/4" primary headers with 3" collectors. Hot Heads supplied a lot of parts such as the 340 oil pump, bronze distributor gear, spark plug tube seals, balancer, adapter plate, bolts, etc... Toping off the flame is a Scintilla Vertex magneto rebuilt by Spud at Fuel Injection Enterprises, they do some NICE work and FAST. All 4 Strombergs are running together NOT progressively.





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That sounds like pure music. Lucky dog...enjoy it.

 

Enquirering minds want to know, what did she pull?

 

This was just to get it running and TRY to get it idling, next week is when we'll know what it makes.

 

nice

 

Another inquiring mind here, look forward to follow-up. Subscribed.
PS: I'm betting this thing is gonna like some RPM.

 

I'm way jealous!

 

That thing sounds sweet! Congrats!

 

Hahaha, it's a nasty bump stick! I'll post up a scan of the spec sheet, it'll wake up around 3500rpm, it's quite a rowdy. There will be PLENTY more dyno videos

 

Here's a short video with the RPMs a LITTLE closer to idle speed, you can really hear how hard it hits.

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Damn !!

I really gotta get stuck back into my blown 330. Donny ground me up a roller stick as well, but more of a blower grind.

Yours sounds NASTY !!!

Great work !!

Rt

 

Schwing!!!!!!! Love the desoto hemi and I am happy so many people are building them latley It does however make it even harder for me to find speed parts Please post up the dyno numbers next week when you get them.

 

Freddy likes it...........nice work !!

 

Sweet! #s?

 

That is one angry sounding engine.

 

Just switched to a computer with speakers, so I could hear it. Whats the bob wieght? Man, that thing sounds like its gonna run.

PS: also what are the valve sizes, and do you have any flow #'s for the heads?

 

I like it a lot! Very nice. Lippy

 

Thanks guys!

The heads are 330 DeSoto heads with standard size valves. 1.94" intake, 1.75" exhaust. The heads were flow benched, but I don't have the numbers in front of me right now.

 

Thanks. I'd like to see them at some point, if possible.

 

that video was engine pron , love the sound , bet your still grinning like the cheshire cat

 

I just watched (and listened) to that clip with an ear to ear grin. Girl on the couch next to me asked if I had a stiffy............ Maybe I did.....
Very nice work man, I hope mine sounds like that eventually. I'm very interested to hear more on your dyno figures.

 

Congrats on a thoughtful build, Noshine! Like food for the eyes, ears and soul. But DeS Hemis are close to my heart, lo-deck AND hi-deck -- like two litter mates, same BUT different!

Do you you have a plan for what it's goin' into? I hope a coupe or roadster, so you can show it off all the time. Given that it ctanked 180-200 @4,400 stock with just the two barrel and around 7.5-1 comp., I can't wait to hear what hp it'll crank @ what rpm, etc., with your Weiand set-up, the beaut headers, 10-1 comp., etc.!

Congrats again!

 

Now that's what I'm talkin' about!!!

 

Awesome, thanks for the music!

 

NoShine, did they give you any figures, or were you doing some more adjustments before seeing how many horses it's acapable of? Just curious for an update, as I don't remember any hp figs given or estimated earlier in the thread.

 

Very impressive. Where did you get the intake? What kind is it?

 

Made 374hp at 6600rpm, has more in it but we were being conservative.

Intake is a Weiand, took quite some time to track down.

 

CONGRATS, NoShine! 374 hp is pretty darn cool for the last of the fast-winding low-deck DeSoto Hemis. That's more than twice the stock '55 Firedome max rpm, and even exceeds what the 345-CID '57 hi-deck Adventurer cranked, stock. Awesome stat without a supercharger, too; kind of like you wrung a TON out of it without going ridiculously exotic or extreme, ya know?

I surely don't blame you for stopping someplace (a more than respectable 6,600 here). The original factory version was hp-rated at 4,400, so I'd guess the DeS engineers wouldn't have recommended running the stock version much beyond 5,500-- just thinking out loud here, ya know?

After such a careful build, who wants to blow a great motor just probing to see where the real RED LINE is? That would be a sort of Pyrrhic victory, even if you got 400 and still ruined the engine. (Heck, In a perfect worked, you could have six of them and "waste" a couple playing, right? LOL.) These don't grow on trees, especially not the special way you build yours up! You may be conservative, but you're SMART in my book! Also, the bore you chose was judicious, so you don't run into heating or other problems.

I've always wondered how far a 291 could go, carbureted alone. THANKS for giving us all some insight on that AND for sharing the results of your well-done build!!!

 

Oh, yeah, I didn't miss when you said "has more in it." Again, KUDOS for not shooting for the moon!

BTW, were the 330 heads a straight bolt-on, or were some "adaptations" necessary? Did you stay with stock valves, or go with something like stainless? Stiffer springs? Bottom end: Did you do anything special on the crank and/or con rods? And, how about pistons -- stock OS or forged? I'm fulla' , or somethin'!

Fascinating mill, man!