Jon Kaase introduces Boss 429 hemi retrofit kit

[Don]

Source: Hemmings.com as published:
Quote:

" Jon Kaase introduces Boss 429 retrofit kit "

" Ford’s Boss 429 hemi was a loaded weapon intended for the NASCAR arena and aimed squarely at its cross-town rival, Chrysler. Unfortunately, Ford only constructed enough consumer versions to satisfy NASCAR, making them exceedingly rare, and as a consequence, highly valued.

Seeing the potential of Ford’s design and recognizing the lasting appeal of the Boss 429’s visual impact, noted race engine builder Jon Kaase has designed all-new components to create what he’s dubbed the Boss Nine Hemi retrofit kit. The kit is intended to fit on a standard Ford 429/460 Lima-style 385-series V-8 without requiring any custom machine work.

The key to the kit is the aluminum cylinder heads, which have revised ports and combustion chambers along with relocated spark plug locations, to enhance airflow and increase combustion efficiency. A new rocker system has also been devised in conjunction with W.W. Engineering to eliminate the potentially troublesome offset design of the original Boss; Manley valves designed for big-block Chevy engines were utilized to maintain parts availability while avoiding the costs of custom pieces. Similarly, the Boss Nine heads are mounted using stock 460 gaskets for the heads and the intake and exhaust ports; it also retains the stock 429/460 oil drain-back holes.

Kaase’s intake manifold is also revised, though it will fit on Ford’s stock Boss 429 heads. Those revisions allowed the new intake to make 50 more horsepower than Ford’s NASCAR single-plane manifold and 100hp over the stock dual-plane manifolds used on production Boss 429 Mustangs. Kaase’s manifold is offered for 4150-style carburetors or for 4500-series Dominator units.

While he was at it, Kaase also designed a new oil-pump housing for the 429/460 to eliminate the factory pump’s tendency to crack. The crowning touch for the Boss Nine Hemi kit is a pair of stock-appearing rocker covers.

To see and learn more, go to www.JonKaaseracingengines.com. "

- By Terry McGe

[RedBarchetta]

Very

But are there any other intake options? Even without the spacer me thinks you're going to be hard-pressed to clear a Cobra hood.



-Dean

[CobraEd]

If the new intake will also fit the original heads, . . . . Then one must assume that the original intake will fit the new heads.


.

[Rare Iron]

SWEET! I'll never forget the ride I had back around 1978 in a REAL Boss '9 Mustang. Some guy in my old neighborhood had a 1970 that was an original paint Calypso Coral car. He had two motors for the car, the untouched original one, & a "tweaked" one. When he gave me the ride in his car - he called it a "Hemi Eater." I was doing a brake job on my '71 Hemi Charger at the time he pulled up in his rarely-seen Mustang. Let's just say he was applying the gas pedal very gingerly trying to hook-up, & finally started getting some traction somewhere in second gear. By 3rd gear, I was ready to crawl under the dash - the car was scary fast!

[FIA-ERA]

Any ideas on pricing? Really interesting to see! I've got a nice 429 Cobra jet block I could get my hands on, MMMM! Any more info would be great! Been to his website and love the new Mustang conversion!

[Great Asp]

These heads look sick.

Would love to see the dyno results from a pump gas motor, 514, 557?

E

[Tom Wells]

Asp,

Here's an older dyno run on a 429 If you look at the top of the message you'll see a comment about the output of the 521.

Link: http://www.460ford.com/viewtopic.php...ight=boss+dyno

Either appears adequate for a street engine, which is what Kaase seems to be mostly interested in.

The 521 is in the 900hp area, the 429 produces well over 750hp.

Nice!

Tom

[OL'BILL]

So, if i have a 429 / 460 block,crank,rods and all accessories what do i need to have a ''Boss 429 Hemi''? I can assume i must need ''Hemi'' pistons to go with the heads in order to work with the hemispherical style chambers,the heads complete with rockers/shafts,and intake,.custom or std length push rods?...what else and of course how much? Am interested if price is right.

Thanks In Advance,
OB

[Tom Wells]

OB,

Go here:

http://www.jonkaaseracingengines.com...bbf-heads.html

and all your questions can be answered. Just don't expect an econo-engine LOL

Regards,

Tom

[RedBarchetta]

"Total width of the Kaase Boss Nine engines on a 10.320 385 series block from valve cover to valve cover is 29 inches."

[Silverback51]

Originally Posted by RedBarchetta

"Total width of the Kaase Boss Nine engines on a 10.320 385 series block from valve cover to valve cover is 29 inches."

Stock 460 it 26 inches, so it's not that bad. A DOHC, 4.6 motor is 30.0

[69boss429]

Jon has really done a great job with his new Boss 429 heads.
A basic package of heads complete with springs,valves,retainers,and rocker arms as well as valve covers is $6000
His new manifold is I think $700
And yes,the stock B9 manifold or the Blue Thunder dual quad will fit but not make quite the HP
Flat top pistons are the order of the day with this combo.
When I get around to building a Cobra it will have a Boss 429 under the bonnet

[olddog]

I think that combustion chamber is more "simi" than "hemi," but you cannot argue with the results.

Me thinks the reason it can use a flat piston is that it is a canted valve on stearoids design.

I would love to have one. It might even be worth bastardizing a Cobra to have a shaker hood to get that manifold on it. I will likely never go that route.

[mdross1]

Originally Posted by olddog

I think that combustion chamber is more "simi" than "hemi," but you cannot argue with the results.

Me thinks the reason it can use a flat piston is that it is a canted valve on stearoids design.

I would love to have one. It might even be worth bastardizing a Cobra to have a shaker hood to get that manifold on it. I will likely never go that route.

Harwood makes very nice looking scoops,Too bad it is such a hassle to post pictures,I could send pictures of mine.My 460 with correct air filter for motor to breath needed a scoop modification.