First Test- KBR Super Wildcat Billet heads

Discussion in 'Race 400/430/455' started by Jim Weise, Dec 14, 2018.

  1. Jim Weise

    Jim Weise EFI/DIS 482

    Hi gang,

    Here's how it went down..

    Mike Erickson, board member and longtime customer and friend of mine, brought his TSP 555 Tomahawk for a mild freshen up and repair into the shop Labor Day Weekend.

    Mike is the owner of the very first production run Tomahawk built, and the second one build overall, Rod Hendrickson had his together first. I finished Mike's first build on Memorial day weekend, in 2010. To date, it has been freshened twice, reconfigured for more power once, and has over 700 passes on it. In current form it made 830 HP at 6300rpm, and pushed his 2500 lbs tube chassis Regal to 8.50's at 156-157 MPH.

    Mike had broken the rocker shaft on his Stage 3 heads, and while he was in the shop dropping off his motor, he was eyeballing Kenny's Billet heads, sitting on one of my benches. He had always been interested in them.. but thought maybe they might be a bit of overkill for a bracket racer.

    I thought, what the heck, this is a great opportunity to do some testing with the Billet heads, and if we could get it together fast enough, we could do some on track testing at the upcoming GS nats. See if we can put together a good bracket race combo, that peaks the power around 7000, and makes over 1000 HP. That's a tall order, typically one has to turn the motor another 1000 rpm or so to get to that 4 digit number. Remember, HP is a mathematical figure, derived from a formula. Torque and rpm are the two main multipliers, so raising the torque peak to a higher rpm is typically required to make big power, especially when your staying Naturally Aspirated.

    But we had some different stuff to work with, namely 500 cfm Billet cylinder heads thanks to Kenny Betts Racing. Let see if we can put those parts to use, and come up with a couple different builds.

    All the parts to do it, except the camshaft, were sitting in the shop, so we went for it..

    A few pics of the teardown, and the initial mock-ups..

    This is the first time all the head bolts were installed and torqued with these heads.. fit was perfect, Kenny did a great job in locating all the holes in all the right places. Stud lengths are dead on..

    Including the 4 studs in the valley.. cool...

    The only thing that a little tricky with these heads, is a bit of head bolt/valvetrain interference.. Due to the locations of the valves, and the use of the stock Buick bolt pattern, we are limited to a 1.500 diameter spring locator, and valve spring set. I was able to locate a set of springs at that diameter, that would work just fine for us. It's tight, but I got it together.

    O-ring fitting..

    Trimmed and ready to seal..

    Speaking of seals, here are the intake spacers for the end rails..


    And all together....


    Checking clearance of the actual springs to be used.. no problems.. Note the valve cover O-ring..


    Valve cover and intake O-rings..not a gasket in sight..


    4 Bolts on the bottom of the valve cover.. AND NO GASKETS....

    It's like I have died and gone to Heaven.. :cool:

    The valve covers are of course Billet, and this stuff fits together perfectly.. as in, you line 1 valve cover bolt up, you can literally drop the other 6 in, and hit them with an electric impact, they are dead nuts lined up.. the engineering and execution on these parts is outstanding.

    OK, so far so good.. next we look at his shortblock, been about 300 passes since I last freshened it.
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  2. Jim Weise

    Jim Weise EFI/DIS 482

    There was no real problem with the shortblock, I could have re-used the bearings, and I thought I had taken some pictures of everything, but I did not... no biggy, not much to see.

    We did see one thing, and that was a very slight amount of wear behind the camshaft.. Nothing major, and this has always been an area I am concerned about, on one of these motors that is using the factory oil pump.. we groove the front of iron blocks all the time behind the cam, and this alum block is susceptible to that also. I have always welded torringtion bearing races to the back of the flange, to spread the load out, but even with that, I could just start to feel the wear with my finger.. I swore I took a picture, but can't located it right now.

    Anyway, here is what we did to eliminate it.. this is something that I came up with for Jim Byers (offbrandracing) Supercharged motor that I am working on now, but we also applied it to this engine.


    For a long time I have been using TH-350 Pump bearings, to replace the thrust washer and spacer on the output shaft of a TH 400.. works great, so I have these bearings around.. When I was doing the research work for Jim's motor and contemplating this area, it occured to me to test fit one of these bearings on the 54mm cam... and it fit perfect... Now, the first thought is to machine the cam flange down for it, but that was nixed as soon as I realize that we would lose thread on the timing chain sprocket.. we don't have much to lose there.. so Mike Gallagher (shortcrank) CNC'ed a relieft in the front of the block for the bearing.

    In this picture you can also see the wear mark I was talking about.. from the big races on the back of the previous camshaft. The OD of those races was just slightly bigger than the OD of this bearing...

    You can also see the slot I filed into the block, from the oil hole to the front, to feed this bearing pressurized oil.


    For a front cam bearing, I use the Durabond HP Ford bearing.. it fits perfectly, and I have used these bearings in this application before, there is no durablity issue, even though they are narrower than the TA bearings. I Used the TA bearings in the other 4 locations.


    This is the TA bearing...

    And the Ford Bearing below..


    The Front bearing installed and lined up..


    And with the thrust bearing in place, for the complete package.. I strongly recommend this modification for all Tomahawk owners that are using the factory style oil pump in the timing cover, either during the initial build, or when it's time to freshen up your engine.. I have shared this info with Mike and TA, and also this modification will be done to every KBR Wildcat iron block with a 54 or 55 MM cam tunnel.


    What I noticed when setting up the end play on the cam.. with the trust bearing on one side, and the bumper bearing on the other, the cam will actually spin freely, even with a slight pre-load... I have set the end play on about 30 roller cams now, and I can assure you that if your a little tight, it locks the cam up right now, you could not turn it with a breaker bar.. so in addition to protecting the block, this mod also should free up a few ponies.

    The only other thing to report on the shortblock, is that even with over 700 passes on it, we needed only about .0015 to make the bores perfectly round and ready to go back into service.. that is awesome, for an 800 HP engine... I have seen iron blocks, making 700 HP, that need up to .008 hone to straighten them out.. It proves that he Tomahawk is a great foundation for this type of engine, and money well spent.. I am glad I talked Mike into it, 9 years ago.

    Next.. the buildup..
    Last edited: Dec 15, 2018
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  3. Jim Weise

    Jim Weise EFI/DIS 482

    Let's start with the new stuff.. here are the heads



    Titanium valves..





    62cc chamber
    Valve material - Titanium, from Victory 1 Performance, Mooresville, NC
    Intake valve- 2.430 diam head, 11/32 stem OAL 7.030
    Exhaust valve- 1.780 diam head, 11/32 stem OAL 6.910
    Intake port volume- 473CC
    Flow rates:

    @.400 316/226
    @.600 421/302
    @.800 480/327

    Max 515/344 at 1.200

    Standard Buick bolt pattern, with additional studs at 12/6 o'clock

    Billet material, with drilled water passages.

    O-ring grooves for valve cover and intake sealing

    Water outlets are -8 ORS

    Spark plug= NGK R5672R-8

    ON the engine..


    Pushrods are from Smith Brothers.. .135wall 3/8 just a touch under 11 inches long... and as you can see, are the bucket type to the rockers, with the ball on the end. There was no clearance issue at all with them, in fact I did not have to "Clearance" anything to install these heads. We left the die grinders in the drawer..

    Jesel Pro Series Individual stand rockers- 1.75 ratio


    Next, the rest of the build, and testing..
    Last edited: Dec 16, 2018
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  4. Jim Weise

    Jim Weise EFI/DIS 482

    Pistons and Piston/wall clearance.

    Pistons are my Diamond 555 pieces, flat top with .300 deep valve reliefs.. this was an off the shelf set that we opened up the reliefs on for the larger intake valve, and then deepened them .050, which ended up not being required.. I was actually surprised at how much piston/valve clearance I had, even with the largest lift and duration cam I had ever run in a Buick.

    Now, there is some question as to exactly how much piston to wall clearance is actually required in this engine. The truth of the matter is that it is an educated guess. Because we chose to open the cylinders up .0015 and get them perfectly round again, I thought it was a great opportunity to really find out what was required.

    We took my standard 4.500 bore pistons, and had them Coated By Line2Line coatings with their APC coating. You can read about it here...

    you can see the skirt coating here..


    Ring Package is
    12 lateral gas ports above the top ring land.




    Pistons are swinging on my standard 555 rotating assembly.. GRP 6.800 rods with 2.200 BE, Crower 3"x 4.365 Forged Crank.

    Up on top, we have to raise the front and rear bulkheads in the valley, to account for the much taller cylinder heads. That is accomplished by these extenders.


    Held in place on either side by a roll pin, and the "lip" that hangs over the inside of the block really helps stop oil leaks here. Installed with a smear of "the right stuff" sealer.



    Camshaft-- This first test was pegged as "the bracket motor"... to me that means an engine that you don't have to turn 8000 rpm every time it's on the track.. again, the goal with this build was solid 4 figure HP numbers, with peak HP right around 7000 rpm. The difference between 7000 and 8000 every time you get on the track may not sound like much, but I would wager that the service life between freshens, and the cycle life of the alum rods, gets nearly cut in half with that last 1000 rpm.

    This engine is designed, from cam profile (valve spring life) to piston rings, to rpm range, to run thru a complete aluminum rod life cycle-- approximately 500 1/4 mile passes. For the average bracket racer, who does a little testing, thats 3-4 years between freshen ups. If you race every weekend, and your going rounds, your still going to get a couple years before having to pull it down.


    Cam specs

    TA 54MM core/ Competition Cams grind

    Lobe numbers 1729R/1758R

    285*/292* @.050
    .498/.485 Lobe lift
    .872/.848 valve lift (zero lash)
    4-7 firing order swap

    I included these next two pictures because I am getting questions all the time about the proper way to assemble the cam bumper..

    The shims go between the large end of the bumper, and the cam, and it is how you set the end play.. don't forget to have the timing cover gasket in place when you do this. End play setting is done here, right after the cam bearings are installed and the cam is test fit.. that way you can put your dial indicator on the rear of the cam, thru the rear plug, which is not in place yet. Also, it's on a table for cam bearings, not the engine stand.



    We will continue the build in next post..
    Last edited: Dec 16, 2018
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  5. Jim Weise

    Jim Weise EFI/DIS 482

    Kenny had the tunnel ram build out in California, and let's just say it was not exactly what he had in mind, but it got us into the testing... a different one is under construction right now, but this one gave us an idea where we were going to be at..


    Water routing..


    Water is fed into the block in the front, like all BBB's, pushed thru the block, and then it transverses into the head via the outboard water hole in the deck. The loops your looking at the in the back of the head tie the two water passages together, which feeds water from the outboard to the inboard drilled passage in the head.


    Up front, the water exits the head cooling passages, and then is transferred to the water remote thermostat housing that is bolted to the front of the plenum, via -8 and -10 pushlock hoses. The Billet water outlet is the installed, which feeds the upper radiator hose.. pretty simple actually, although we did have to drill a bleed hole in the top of the T stat housing to bleed the air out of the system, during testing.. just a simple 1/8 pipe plug worked fine, crack it until all the air escapes..

    This motor also uses a crank trigger, along with a mandrel drive for the GV motorsports super pro vacuum pump, and the alternator, as you can see here..


    And a few final pics, before we put it in the car, to do the remaining brackets and check all the fits.

    Here is something interesting we had to do.. because of the spacing of the intake ports, there was no room to mount the linkage manifold bracket, which usually goes on the LH intake flange, often secured by the center two manifold bolts.. no such luck here.. so we put it under the manifold... and it worked great.. My dyno guy said it was the first one he had ever seen like that.. which is saying a lot, since this motor was the 9904th motor he had done.

    We also added a cable mount..

    And the regulator and fuel lines..


    And plug wires.. DSC02179.JPG
    Yes, your eye's are not deceiving you, a stock distributor fit best.. so we used a fresh reman.. it's locked, and simply spins the oil pump, and distributes the spark. The crank trigger takes care of the timing.

    We tentatively mounted the vacuum pump, but that would have to go in the car to finalize it..
    Last edited: Dec 17, 2018
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  6. Jim Weise

    Jim Weise EFI/DIS 482

    So next, we dropped in in the chassis.. let me back up here a bit.. we actually had to completely re-fit the motor in this car, the way it was mounted, it had so much angle, the tunnel ram intake hit the windshield about a half inch before the bellhousing came together on the engine/trans... It had half plates on the heads, and we upgraded it a full front motor plate.

    A few pics of that work..

    Blocked it up in place after removing all the old mount hardware and tabs..


    Built the motor plate template from Lexan..

    Right away, we noticed that there would be an interference issue with the distributor.. These heads are longer than the cast heads, so we actually have to shim from the block mounts to the plate.. No way we have enough room for the typical 1/4 inch alum motor plate..


    As you can see here, we even had to clearance the intake manifold back a bit.. really did not have to touch the heads, just rounded the corner a touch, but you can see here, there is absolutly no room for the distrib with the 1/4 inch plate.. the lexan was 1/4" and that is what you looking at there.

    My solution was to go to a 11 ga steel front plate, that we could bend right in that area, for distributor clearance. You can see it in this picture...

    Future runs of heads will have them shortened slightly, so that LF head will not hang over the block.

    This is why Kenny has me doing this work, to figure it all out, before he sells them to anyone.

    So after we cleared that hurtle, had the front and mid plate mounts finished, and the motor built, it was time to drop it in and do the final brackets and check the fit of everything.. including the hood.. :eek:



    Mounting the Oberg 600 oil filter... I consider this filter an absolute requirement for an engine like this.. the large 60 micron screen in this filter will show you everything.. and I mean everything... typically freaks people out who first see one, after the motor has been broken in.. because engines do shed metal when new... and this filter will show you every speck.. It has no bypass, no paper pleats or tightly wrapped mesh to hide the particles... that's important because if you watch it like a hawk, it will tell you when something is going away, long before it costs you thousands and thousands of dollars to fix it. And it takes less than a minute to check it, and you lose only a couple oz of oil.. A must have when you stepping to the next level, in my opinion.



    And off the the dyno we went...


    No, ignore the screen behind it, the 494 we took off the dyno before we installed this beast, made 708 HP...


    As you can see, we started with single carb testing... with a pro systems 1250... I figured it would not like that, because the manifold is really designed to have one carb barrel over each intake port.. distribution with a flat plate leaves a lot to be desired.. 90 HP on this motor..

    On to the testing..
    Last edited: Dec 17, 2018
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  7. Jim Weise

    Jim Weise EFI/DIS 482

    As they say, "a picture is worth a thousand words"


    Video must be worth lot more..

    Here is the sheet on that pull..

    Best pull intial session.JPG

    And the Graph of HP and Torque

    1061 graph.JPG

    Mission accomplished.. shift her at 7 and run it thru the traps about 7200.. there is 10-20 more HP there if I really worked it, but just a couple pulls showed us the potential.. it was getting late by now, so we wrapped it up, unhooked, loaded up, and went to dinner.. a good day.

    Next up, the higher rpm cam has already been spec'ed in consultation with Jones cam designs it should be in the building here in a few weeks, and then we the new intake gets built, we will go test again.. I will test the new cam with both intakes.. so it will only be a cam change..


    Last edited: Dec 17, 2018
  8. Smartin

    Smartin Staff Member

  9. OHC JOE

    OHC JOE Mullet Mafia since 2020

    :eek: it's a good thing we can't express our thoughts with foul language
  10. GS Kubisch

    GS Kubisch THE "CUT-UP" BUICK

    Thanks for the write up Jim.

    Congrats on getting it all together. Sounds like a lot of work in short order.
  11. rex362

    rex362 paint clear and drive

    Holy Moly
    Briz and OHC JOE like this.
  12. mbusher83

    mbusher83 Well-Known Member

    Nice work guys...I can’t wait to see more!
  13. hugger

    hugger Well-Known Member

    I called to and talked to Mike Jones , he will be doing my cam as well
  14. Bens99gtp

    Bens99gtp Well-Known Member

    awsome results, especially seeing this was not a build to ring every last hp out it. but build with the intention of this motor staying together a few seasons at this power level, 7000 on a set up like this should have no worries
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  15. ozarkian

    ozarkian Rush is Right

  16. sriley531

    sriley531 M.M.O.G.

    HOLY SMOKES! AWESOME piece and write-up!
    OHC JOE likes this.

    JESUPERCAT No Slow Boat

    Great job Jim.
    I like the way you format your build write ups.
  18. Steve Reynolds

    Steve Reynolds SRE Inc

    OHC JOE likes this.
  19. carmantx

    carmantx Never Surrender

    Very nice power and the heads and all look great!
    OHC JOE likes this.
  20. Briz

    Briz Platinum Level Contributor

    Thats what I said!

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