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“More than 70 years ago, Zora Arkus-Duntov and his brother, Yura, developed the hemispherical overhead-valve cylinder head for the Ford Flathead. Known as the ARDUN head, it radically altered the performance capability of the engine, offering a dramatic increase in horsepower that was due not only to greater airflow, but an increase in the effective engine speed, which allowed it to make more power at high rpm.
It’s that same quest for high-rpm horsepower that pushed Mercury Racing (a division of Mercury Marine) to develop the SB4 7.0 engine; an automotive crate engine that, in a nutshell, uses a GM LS foundation (the LS7 cylinder block) with an all-new, custom-designed set of four-valve, dual-overhead-camshaft cylinder heads.”
That Zora reference has probably been discussed ad nauseas somewhere on CF, but I haven’t seen it. Interesting though.
Can we all agree that the sb4 looks terrifyingly similar to the LT-5 (the real one, not the crap that gm currently calls the LT-5) I guess that intake runner setup did work well.
Can we all agree that the sb4 looks terrifyingly similar to the LT-5 (the real one, not the crap that gm currently calls the LT-5) I guess that intake runner setup did work well.
I think that some time ago, 2014,2015, GM contacted a couple very trusted suppliers and tasked them with developing a naturally aspirated sbc that would produce over 700hp as proof of concept. It’s anybody’s guess on how they will transition that into a full blown production engine for the C8-but they will.
Here’s a pic of Katechs stab at it from 2016. Same year Mercury brought SB4 to SEMA:
note the similarly polished look, a requirement for the mid engine c8 I’m sure.
My bad, the article I read a while back claimed 500 lbs fully dressed, I just looked at the merc brochure to recheck.
As for the size, yea its bigger. But it ain't like a coyote vs an ls. The block is the same physical size unlike the coyote that is big for no apparent reason.
Idk how accurate the brochure sizing is but its allegedly only ~5inches wider. Its impressive to me they got it to the size they did. (Idk where the attachment went...)
Width from outside of the head to outside of the head is about 30" for the SB4, the same measurement for an LSx is abour 22".
Dimensions showed are skewed eitherway as the LSx has ehxaust manifolds and the SB4 does not. Not to mention the LSx is in Corvette trim with the alternator located up top rather making it look way wider than what it is.
Width from outside of the head to outside of the head is about 30" for the SB4, the same measurement for an LSx is abour 22".
Dimensions showed are skewed eitherway as the LSx has ehxaust manifolds and the SB4 does not. Not to mention the LSx is in Corvette trim with the alternator located up top rather making it look way wider than what it is.
Fair enough. I thought an ls was more like 26 and gen 1 was like 22. Oh well, it's still smaller than a mod motor or a coyote.
03-20-2019, 08:54 AM
