KB5

I just picked up a KB5 standard cam block for a project. I am curious on options out there for heads. This is a new to me deal so I am trying to learn a lil. Had a deal on some iron heads but they were bad.

I see different lifter offset heads out there but this is a 1.800 spread. Are offset lifters used to make up the difference maybe? As in use a 1.9 or 2.0 lifter spread head on a 1.8 block?

Thanks in advance...

 

If you were looking at iron heads, I assume you are not gunning for maximum performance - What is the goal for this build?
We ran old BAE fuel heads on a KB3 for years (combination still running actually).
For a no hassle budget build, I would recommend getting a good set of used fuel heads and go from there. Parts are plentyful and you can make it run pretty good on a limited budget.
Just my 2 cents - Maybe someone else feels differently.

 

I agree that fuel heads work great but I think the good ones are getting hard to find. I would look for a good set of BAE 2000 series or AJ Stage Ii. Avoid Dart or Veney because of age and many variations over the years. The current fuel heads are .100 tall and therefore have a combustion chamber of more than 190cc. I know some pullers are trying these on alcohol.

 

Thanks guys...I appreciate the input.

 

I was told way back when I had a 1.8" Lifter spread that you cannot run Fat heads with the 1.8 spread however others have told me with some clearencing you can, The 2" is the current standard for Alcohol heads and I have heard the 1.9's can run either. The 5 is a good block and will hold a surprising amount for quite a while, it's the oldest one they still make parts for. I think I still have a KB 5 mock up block here. For the real high HP stuff I would recommend the stg 10 or 15 blocks or a Billet block for longevity/Repair-ability. A good set of used fuel heads like BAE or AJPE stg 2 heads work great on alcohol and run about $2,000-$2,500 a pair. The BAE 5 Fathead (Alky head) stuff is going for around the same price. The old Dart and older fuel style Veney head stuff is getting hard to find parts for so I would avoid that. The stg 1 and 2 fuel heads are good for alcohol, from stg 3 to the current stuff the decks grew which made the chambers bigger (Not great for alcohol) and you have to use a std deck block with a +.100 intake, I have heard they make +.200 intakes for use on +.100 tall blocks but am not certain. Hope that helps,
Trevor Sherwood

 

Thanks Trevor. It's a new direction for me. We don't need big hp to start maybe 1400 max at the moment. But in racing another platform I have learned to try to invest forward. I'd rather look for a fat head that will work and I can use toward more to later on. I am curious about the clearance idea... any more info I can collect on that?

 

Your welcome,

I have not tried it personally as I traded all my old stuff out before going to the fathead deal and unfortunately I doubt I have enough spare parts on hand at the moment to test that theory but will try to take a peak this weekend with what I have on hand when I am not running around and see if I can see anything.

A fuel headed hemi will make 1400 hp easy with any 14-71 and you wouldn't have to overdrive it much if any though you are correct in going the fathead route for later use if you are looking for 2400hp+. The fuel heads like timing like 32-34 degrees max vs the fatheads 26 but the pistons are heavy due to the massive chambers so they do not like RPM. Fathead 5's can be found cheap and used rocker gear goes for around $2500 a set, the intakes are very hard to find used nowadays and they are usually back ordered from BAE though AJPE may be quicker to ship and will work the same. Pistons, rocker stands, shafts, and exhaust rockers, valve covers, headers, and intakes are specific to fatheads, later you can upgrade heads with little effort. BAE 4,5,6,7,8, and the current 10 series take all the same big parts but pushrod length and the exhaust port shapes change.

Feel free to call if you need any help with figuring out the hemi, Mon through Thursday from 3-9 pm Eastern time I am usually out and about but I am free on Fridays and weekends and would be happy to help. Trevor 727-364-4368

 

I run BAE Fathead on a KB 3 block with stock lifter spacing. It did require some grinding in the valley to make room for the push rods but it is possible.

The pushrods are tappered mantons, I cant remember the amount of tapper but I can check if you want me to.

Hope it helps

 

Oh man that would be awesome!! Thanks guys for all the info!

 

We ran BAE fuel heads for years. For stout but not all out alky combo they are great. If you plan on running a screw blower or turning motoro much above 9000 or so then I suggest spending extra for newer heads and better rocker assembly. I should have changed fat head when we where runnings .9500 rpm shifts where too much and cost me money and TA/FC ihra championship.

 

KB 5 was standard TF issue gor while and handled 8000 hp on regular bases. Is it modern billet block,nope.Are making 10,000 hp ,not on alky. Should make for strong bottom end.

 

The Push rods I run in the KB3/fathead 3 combo are:

Intake manton 5 series 7/16 to 3/8 x 168 11.845 in length (manton item number 516-168)

Exhaust manton 5 series 7/16 to 3/8 x 168 11.845 in length (Manton item 516-168)

I have about 30 runs on this and everything still looks brand new.

 

Thanks a bunch!!!