On Center Build questions

dank GN

BlackArts Automotive (661)993-8277
Joined
Jan 11, 2009
Okay i have recently started a On center build . it will be going in a street car. i have the complete set up to go with stage 2 heads IE heads,Intake. but im hearing that the stage 2 heads are to much for the street. so will TA heads bolt up to a oncenter block? if i go that route can i bolt a stock style intake on those heads? I am also in the market for some wide journal on center rods . my set up is with dutwiller at his shop. i need rods and pistons to get this short block together. i am trying to be as cost efficient as possible. is there headers for the stage 2 heads out there that i will not have to give my fist born for? basically what rote should i go any help would be appreciated . what other issues will i run into with this build? thanks again guys
 
The only difference is the intake. Production style heads bolt up. TA sells the intake (made by champion) that works. As far as pistons and rods, how fast do you want to go? I have $1400 billet Crower rods and $1400 custom pistons in my engine. When you plan on making 1200+hp, piston strength is an issue. Full throttle has 4.1 pistons available,and K1 or Molnar rods are very nice for the price.
 
If Duttweiler is building the engine, you really should rely on him for these questions.

How many cubic inches are you planning? Stage 2 heads might not be too bad if you're building a building a stroker and choose the right turbo.

Yes, you can bolt TA or Champion heads to an on-center block. You will either have to run a champion on-center intake or a modified stock intake (ports and bolt holes shifted on each side).

There aren't many choices for on-center wide journal rods. New Crowers are the best. DLS might have some of his rods in that configuration. Used carillos pop up from time to time, but I personally wouldn't use a used rod.

There is no cheap way out on stage 2 head style headers. Wait for a used set of ATR's or have some custom built. Of course with champion ot TA heads you can run any of the regularly available or even stock headers.
 
You've headed into the abyss of stage iI vs. stage 1 style (stock) heads. Definitely recommend you read old threads and look at others combos to really figure out what direction to go.

Is it correct to view your signature as the fastest you've been currently? If so, you're really about to take a huge leap in power you may or may not be ready for without someone really close to you guiding you along (away from headaches). Stage II heads, all else equal, give up some low end torque. The other issue you've found is readily available parts.

Recommendation is to take your time and find a builder to guide you through and through. If it's duttweiller, than of course you have an expert with you - you probably need to listen to him more than anyone if he is doing the motor. Be very very clear what you're trying to do with it or you will not be happy.
 
Going with production style heads, the parts are readily available. With Stage 2 heads, you'll need custom headers, modified intake, modified doghouse, modified IC pipes, modified throttle linkage, yada, yada.

Also, if you are planning to use on-center block in a street application and put the stock accessories back on, you need to shim out the crank pulley .120" for the accessories to line up.

Billy T.
gnxtc2@aol.com
 
In my sig. is what your trying to do with stock parts, with just GN-1 aluminum heads on it's hard to keep the tires on the ground at any speed when you start to get into it, One other thing you will have to do is run a oil line from were the oil pressure sender is to the front timing cover on the drivers side and make a oil sprayer for the cam gear and cam sensor , also the intake will have to be machine .60 thou on the sides and .84 on the bottom to make it fit.
 
In my sig. is what your trying to do with stock parts, with just GN-1 aluminum heads on it's hard to keep the tires on the ground at any speed when you start to get into it, One other thing you will have to do is run a oil line from were the oil pressure sender is to the front timing cover on the drivers side and make a oil sprayer for the cam gear and cam sensor , also the intake will have to be machine .60 thou on the sides and .84 on the bottom to make it fit.
You block must have been milled to have to machine the intake. The deck height on my block is 9.515, it required no special intake mods.
 
Thanks guys yes I know I am taking a huge leap in power and I understand it will take time . Dutwiller is building my long block and I will be depending on him for a lot of the wisdom when it comes to the combo that will best suit my needs . I'm sure I will have a lot of stupid questions in the coming months and I appreciate all the input from you guys thanks again


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Update got rods finally single pass Carrillos . Now just saving some cash for the custom pistons needed . Kenny D has been awesome to deal with a genuinely nice guy . Should start assy soon . Kenny D Has some stage 11 headers that he is willing to part with . So it looks like I'll be sticking with the stage 2 heads. Need to swap out valves still on the exhaust side
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Chris,

What's the bore size on that block? The cylinders look pretty big. I like the new valve covers, I think Allan G is looking for a set if you want to sell them.

Neal
 
Neil,
That is exactly what I'm looking for but I think I have an even better solution in the works.
Allan G.
 
4.060 . I know it's a little on the big side but Kenny said there is plenty of meat in the block . Virgin block that they just went strait to 4.060 :-(
 
4.060 . I know it's a little on the big side but Kenny said there is plenty of meat in the block . Virgin block that they just went strait to 4.060 :-(

Chris,

I've actually seen that done more than once. Back when the blocks were readily available I'm sure it wasn't a big deal to bore it .100" over from the start. They probably didn't give it much thought, these days it would be a different story. On center blocks have more meat in them than Off center blocks do so the 4.060" bore should be fine.

Neal
 
Hopefully your S2 heads have not been too heavily hogged out. Many of the retired race heads were ported to an extreme that made them even more difficult to use in a turbo car, let alone one that you would want to drive on the street. The velocity is dead under 5000rpm. Also keep in mind that the entire combo, once together, will likely be a far cry from a typical 10-sec 109 build in terms of "street fun." I've seen a few milder on-center builds online that claimed to have more stock-like responsiveness and manners, but have never seen one in person that ran that way.

Look forward to seeing your build.
 
Looks like you are well on your way, Kenny D will no doubt build you one hellava engine. Your re-sale value will be sky-high with Kenny's name plate on the engine. Looking forward to your build. RichardV6 just put together a S2 headed street car, ask him how it runs under 5k.

Mike
 
I'd like to suggest.. a smaller TB & Turbo for cruising the street.
(it will still get you in more trouble than your good attorney will want to deal with btw.)
 
I drove mine ( oncenter build with stage 2 heads) on street for first time this weekend for some learning on fast system and checking for leaks and such. as far as normal driving seemed like a normal 109 build..right now getting boost controller all setup .should know more on power and lagyness soon.
 
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