What is this engine?

Thought I knew pretty much every V8 that was put into a US vehicle. Was at car show and saw this. Any intel about what it is?

Looks like a Buick nailhead to me.

Yup. Nailhead.

Correct, it's a nailhead. Nice, light, torquey engines.

Gonna put it in the 1800ES?

Google Tommy Ivo's Showboat for nailhead inspiration for the Molvo.

Fancied up nailhead. Saw a normal on this morning. I was told Buick had the first OHV v8.

"Nailhead" would have been my first guess since I do know the term, just not seen one before.So the finned cover on the side is just aftermarket bling.

I do like it, but no...gonna stay with the 302 for the Molvo; it's the right engine for the overall project.

It was kind of an interesting engine, in that they had almost centrally located sparkplugs in a pentroof-like chamber, but the intake and exhaust valves were side by side on half of the pentroof. The pushrods crossed under the rocker shaft like the intake rockers of a Hemi. So in a sense it was like a 16v engine with two of the valves missing, breathing-wise.

(jeez, I'd never seen a cutaway of the exhaust before, just the intake... horrendous! Don't let oldskewltoy see this!)

They also had fairly big cams from the factory to make up for the lack of ability to breathe, which lead to complaints about rough idles, which led to the abandoning of the engine.

They made cams and manifolds to switch the intake and exhaust.

NOHOME wrote: So the finned cover on the side is just aftermarket bling.

The cover is aftermarket but nailheads did come with a stamped steel cover in that spot to hold the ignition wires.

When I was a kid, my dad had a 30 Model A 5 window street rod with a nailhead in it..

I always recognize one when I see it..

Fun fact:

When Buick used the 401 nailhead as their muscle car powerplant, the number designation on the air cleaner was not the displacement but the torque output.

The Wildcat 445 is not a 445CID engine, it puts out 455 lb/ft of torque.

Think the LS7's 12 valve angle is sweet? The Nailhead had an honest-to-god 0 valve angle! The nickname "Nailhead" came about because the heads of the valves were joked to be the size of the head of a nail.

Despite that though, they had a pretty successful race history. Tommy Ivo ran them in his T pickup, his single-engine rail, his twin-engine rail and his 4-engine rail. Troy Trepanier just recently built a gorgeous Buick with a twin-turbo nailhead that was beautiful.

Whippet Good!

NickD wrote: Think the LS7's 12* valve angle is sweet? The Nailhead had an honest-to-god 0* valve angle!

You mean 45 degree valves. Valve angle is measured relative to cylinder bores.

Knurled wrote: It was kind of an interesting engine, in that they had almost centrally located sparkplugs in a pentroof-like chamber, but the intake and exhaust valves were side by side on half of the pentroof. The pushrods crossed under the rocker shaft like the intake rockers of a Hemi. So in a sense it was like a 16v engine with two of the valves missing, breathing-wise. (jeez, I'd never seen a cutaway of the exhaust before, just the intake... horrendous! Don't let oldskewltoy see this!) They also had fairly big cams from the factory to make up for the lack of ability to breathe, which lead to complaints about rough idles, which led to the abandoning of the engine.

For a 50 year old design... love the intake side.... exhaust side just looks painful

I remember the first Nailhead I put in a customer's car (50 Ford). 16 torque converter bolts. I had no knuckles left.

If that cutaway draying is really accurate, the is zero material in there to allow any porting at all...

iadr wrote:

Knurled wrote:

NickD wrote: Think the LS7's 12* valve angle is sweet? The Nailhead had an honest-to-god 0* valve angle!

You mean 45 degree valves. Valve angle is measured relative to cylinder bores.

yes. 45*

Huh, whoops, could swear I read several sources that said it was 0. Or maybe I'm thinking of the Oldsmobiles that had something like 6

cabbagecop wrote: They made cams and manifolds to switch the intake and exhaust.

Nailheads are awesome.

In reply to slefain:

Okay... why would one do that?

Knurled wrote: In reply to slefain: Okay... why would one do that?

And also forced induction can make up for the brutally horrible exhaust port flow. The intake had a better flow path, so using it for exhaust helps it breath easier.

In reply to Knurled:

Because LOOK AT IT

EDIT. I was so stunned by the glory I initially failed to notice it's in a FRIGGIN' BOAT!