RARE INTAKE MANIFOLD
- Thread starter '68cuda416
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You would have to make some pretty elaborate spacers due to it being cut at a new angle. Also the front and rear will be short. Been there when Ryan at Shady Dell ruined mine. My X block was 890 deck with small block chevy rods for small pin diameter to keep them under the Comp. rings. Usually those intakes are specific to the engine they came from. Once you go under a 910 deck your at the point of no return with parts you used.
pishta
I know I'm right....
@Oldmanmopar How does the intake angle change? Aren't the decks just cut -.100 (eg) square toward the crank centerline? Seems they would just sink in the same plane and keep the original angle, just having them closer physically. So your spacers would be the same thickness but your china wall gap would be huge...? Set us straight.
JDMopar
Well-Known Member
I saw one for sale in the swap meet at The Mopar Nationals in 1985, for $25. I passed on it because it was all greasy and I thought it was some home made rig! 
But, back in those days...$25 was the going price for a used LD340.
But, back in those days...$25 was the going price for a used LD340.QuickBpBp
Well-Known Member
When you deck the block you are shrinking the angle surface on the bottom port side of head. Therefore the intake can't sit down where it needs to be. It's simple geometry. IMO The correct way is to the cut the intake port side of head to get the correct angle and you can run any stock manifold with-out issue or leaking oil or sucking oil in the cylinder. If it's cut really hard there is more to be done as the front and back rails become an issue also.. Hope that makes sense...
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All I can say is good luck with it. They also cut the whole separator out. so the dual plane advantage is gone. It is a cool piece but unless you have w2's or oval port Batten heads you would be better off looking for and old Wieand, Offenhauser, or a true LD340. You will have less issues. We have one he used on a plastic mock up motor picked it up for $75. Look at local track swap meets
I asked my son he said the angle may not have been changed. BHJ makes an intake angle gauge to check it . They are not cheap. BHJ Products.
Special spacers will have to be made and then double gasket it. He said its not worth doing it. We saw that intake it was around $300 on Facebook. Get a new air gap they fit nice. Todd has the intake off of this motor and others. Ask him probably get it reasonable
I asked my son he said the angle may not have been changed. BHJ makes an intake angle gauge to check it . They are not cheap. BHJ Products.
Special spacers will have to be made and then double gasket it. He said its not worth doing it. We saw that intake it was around $300 on Facebook. Get a new air gap they fit nice. Todd has the intake off of this motor and others. Ask him probably get it reasonable
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gzig5
Well-Known Member
What good is an Air Gap going to do for his W2 heads?
pishta
I know I'm right....
Not really...? Let me restate my observation and see if that is what yours is: When you (zero) deck a block you true up the deck height to the crank centerline, maintaining the 90 degrees to it, making it completely 90 to the crank CL ...and then you do the other side. You dont take more out the 'bottom' than the top, 'shrinking the angle surface'..that would cause the head bolts not to align! When both sides are square, they are 90 to each other too, pull .125 off each cylinder bank and your still 90 to each other, and the intake angle is still xx degrees...what it was! No need to correct it, you just fly cut it across to make it more narrow, but still xx degrees. Only now its closer but it still is parallel to the original xx angle. Its simply a matter of using a thicker intake gasket or a spacer if its beyond what a gasket could fill. @SGBARRACUDA were your Stage VI spacers milled at an angle or were they just flat stock? Maybe its just how I read that, maybe were on the same page?
That I can't say. I picked them up and never used then.
Commando66
She's a beaut Clark!
I bought one from Keith Black in about 1995. Sold it to a friend and it “disappeared”.
autoxcuda
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I clarified what I wrote about 1970 season Race T/A heads versus Street T/A heads.
This is accurate but light on what happens because you covered the block and what should happen, but doesn’t always. The heads & intake need to also be perfect OOTB for a new head and the OE is not even close.
The same thing you did to the block no applies to the heads and then the intake.
After zero decking the block, it is now shorter in overall height. (No duh, I know, info for new guys) the cylinder heads also need this treatment. Starting with the deck. Then a measurement angle wise on the intake side of the head. IF! The angle meets the spec to mate to the intake, we now move on to the intake. Same again. Check angles, mill to correct.
Now we are left with the front to rear geometry & angles. Let’s just say it should be level from front to rear. This is not always the case so you need to kill that. Now you have two killed surfaces on the intake to meet the head. But your not done because there could be a height difference between the front and the rear even though everything else has been squared.
Sometimes you’ll have to shave off a small amount on the rear of the intake to get it flush on all angles. Up/down, side to side, left to right.
This is actually quite common in building an extremely well fitting host of parts. The great thing is aluminum does bend a good bit to conform to the Irregularities that could be present.
Now that I typed this out, I just thought of something. I could have saved time by sending everyone to a Hughes engines link. (At the moment I don’t know where it is, but on the Huhgesengines site…..)
Most of the time, unless it is an extreme build, you can get away with less machining and it’ll all work.
To say THAT intake above is wall art is IMO a stretch. It assumes a lot. Which is possible. But worth checking. Even if the assumed cuts were really heavy, the notion that it is cut beyond use is also a stretch. Unless it is cut Bizarrely huge and it’s amounts. And it doesn’t look so. The rest of the parts below the intake can be machined to match. The only way I see it is not fitting or being used is that if it was for use on a odd, non-stock deck height block. There may not be enough to mail on the intake or the cylinder head it made to to fit on a short 9.00 or less height block.
QuickBpBp
Well-Known Member
Probably did not explain it right for you to understand. Does not work that way as intake side of the head is not 90º to the head deck side You are cutting away at a V Shrinking the SAME angle down and as you get lower the intake also needs to be narrower like the cut one here that honestly would be a nightmare in MY opinion to match but could be done.. Don't know how to explain it better it may only make sense to what's goin on to me but I am sure there are others who build motors every day that can easily explain. I only put 5-6 together over the years..
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Here is a shot of my RPM intake to RPM heads that needed to be cut .070 it sit just right. The same amount was taken off the bottom where it meets the China wall.
I hate to say this, but I don’t remember how much the heads were milled exactly. IIRC, (and that’s bad in this case) the heads were milled down to remove 3 - 5cc. Then on top of the milled block, how much I don’t remember again (sigh, I know, paper work is in a box somewhere. I’m in the middle of moving to a new state)
And then there is the head gasket thickness. All of these altered Dimensions add up and throw everything out of wack. As mentioned above, (Thanks quickbpbp) the shrinking “V” becomes an issue as well. Hence the intake to head face milling that is a must and then the core and aft, then the angle of which it sits on.
I hate to say this, but I don’t remember how much the heads were milled exactly. IIRC, (and that’s bad in this case) the heads were milled down to remove 3 - 5cc. Then on top of the milled block, how much I don’t remember again (sigh, I know, paper work is in a box somewhere. I’m in the middle of moving to a new state)
And then there is the head gasket thickness. All of these altered Dimensions add up and throw everything out of wack. As mentioned above, (Thanks quickbpbp) the shrinking “V” becomes an issue as well. Hence the intake to head face milling that is a must and then the core and aft, then the angle of which it sits on.
QuickBpBp
Well-Known Member
Thanks for posting this. This is exactly what I said would happen the intake is touching at the top and the gap is at the bottom of the intake port...
Tolerance stacking. I had the same issue with my 273. Heads were surfaced and the gaskets were different. I had the heads torqued so I chose to machine the manifold. (it was the wrong number for the car anyway) After machining the intake gasket surfaces, it fit in perfect with a small gap at the china wall. Just perfect for a bead of black rtv.
Your welcome. These little details get lost and/or not really spoken about because the machinist takes care of you without much fan fare in telling you to very last detail unless you ask for a blue printed engine where every last thing is scribbled down for your notes.
The machinist may just say, we milled the intake down .060 to fit right but not say or give every last detail. For most, it’s not a big deal at all.
The machinist may just say, we milled the intake down .060 to fit right but not say or give every last detail. For most, it’s not a big deal at all.
pishta
I know I'm right....
OK< we got the same principals down, its just explaining it 6 one way, half a dozen the other. 
A 'shrinking V' is no problem as the intake angles dont change. I use a drafting table with a rotating T-square and a triangle if I put the T at a 45 (block angle) and the 30-60-90 triangle on its edge at one point (30 degree intake angle) , I can slide the triangle up and down the T (deck height change) and the "intake angle" is always the same 30 no matter where the triangle slides on the T-square. This is presuming a zero cut deck or something close enough that worked prior to a parallel deck mill. Get it all square and itll fall into place. 
A 'shrinking V' is no problem as the intake angles dont change. I use a drafting table with a rotating T-square and a triangle if I put the T at a 45 (block angle) and the 30-60-90 triangle on its edge at one point (30 degree intake angle) , I can slide the triangle up and down the T (deck height change) and the "intake angle" is always the same 30 no matter where the triangle slides on the T-square. This is presuming a zero cut deck or something close enough that worked prior to a parallel deck mill. Get it all square and itll fall into place. 
'68cuda416
Well-Known Member
Well not for the reasons stated by OLDKIMMER but this intake probably will be wall art and or a conversation piece as im having a LD340 cut into quarters, heavily ported and modified, W2 ports integrated into it and then rewelded back togethor for a personal project of mine so it will to some degree mimic this intake but just severely modified. I didn't want to cut up such a rare intake but since money isn't a huge concern to me and I like hoarding quality small block Mopar parts I still chose to buy it. If I ever wanted to use it my engine builder would make quick and simple work out of making spacers and or whatever else would be needed to make it work perfect.
OK, my head is spinning.
Your cutting up a LD-340 to mimic the W2 LD-340?
Your cutting up a LD-340 to mimic the W2 LD-340?
512Stroker
We are all here because we are not all there.
Is your engine builder close to us here in MO?
'68cuda416
Well-Known Member
Yes sir.....It's for my late fathers 68 GTS......he told me he wanted to see it restored and on the drag strip but since it's a numbers matching very nice car I had to figure out a way to do it without ruining the integrity of the car but yet still be extremely impressive. The plan is to do a " loose " interpretation of what the F.A.S.T. guys are doing so it will for the very most part look bone stock with a stroked R3 block producing 440 cubic inches, ported W2's, extrude honed factory exhaust manifolds, a 1000 cfm Competition series Thermoquad, and the heavily modified LD340 intake, that is just some of the details.
'68cuda416
Well-Known Member
No sir I have Brett Miller in Pennsylvania do my engines which has been great and also will use Gaby Labiosia with EIC Motorsports in Florida for some porting and induction work as he is arguably one of the very best in the country.
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