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My first post...lots of questions..

Mark Barnes

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Hi everyone- Have a '66 383 that I'm planning on rebuilding to stuff in a 67 Belvedere ll. I would like to have a moderately snappy street car that could make a pass or two at the dragstrip...for fun. Reusing the original iron 516 heads, (yeah, I know people don't love them), so a couple years before I read all the input about better flowing heads, I had already put 2.14/1.81 stainless valves and new springs in them. My question is... in an attempt to get to 10:1 compression, with zero deck height pistons, measured 76cc chambers, a .005 cleanup cut on the heads, .039 FelPro gaskets, stock crank...I assume I'm gonna need valve reliefs in the pistons? One (stock rockers) cam I'm considering is Lunati Voodoo 262, but it's probably gonna screw me up with the lift. I've looked at a million combinations till I've gone crosseyed, and I'd appreciate anyone's input or help, as I'm not the best Mopar guy by a longshot. I know I probably haven't provided enough info, so please tell me what else you need to make an informed decision. Thanks.
 
Your going to be north of 11:1 static compression with that setup. I'd look at thicker gaskets as a first step. Notched pistons will help decrease your compression and may be required depending on the cam selected. 440'
 
do figure your compression
look a what 10:1 pistons? the sp ones or?
do no be concerned about cam lift
it's lift when the piston is before tdc or after tdc depending if you are looking at the intake or the exhaust
so duration and lca
lunati good choice
67 had closed chambers with 10:1 pistons
 
do figure your compression
look a what 10:1 pistons? the sp ones or?
do no be concerned about cam lift
it's lift when the piston is before tdc or after tdc depending if you are looking at the intake or the exhaust
so duration and lca
lunati good choice
67 had closed chambers with 10:1 pistons
Ya know, I didn't think about WHEN the valves were fully open. Duh.
Yeah, I would like to use the 2315 SP pistons, but they're flat tops. I could use the KB 162's, they have valve reliefs, but lower compression height than the SP's.
The cam I'm looking for should come in early and hang in to around 5800 rpm, which is all I'll ever need. I hope this Lunati does that. My kid probably thinks different, and he'll bring the motor home in a basket one day.
Any idea what kind of converter would be good for the 727 with maybe a 3.55 gear behind it?
 
the voodoo cams call for 2400 stall, 800 cfm, and 3.70 gear. their recommendations.
 
My .030" over 383 has flat tops with no valve reliefs, and are .020" in the hole. Your head CC's sound very close to mine, I have 2.08"/1.74" valves, and a light mill on 516 heads also. With a .039" gasket, my calculated compression is 9.96/1.
 
My .030" over 383 has flat tops with no valve reliefs, and are .020" in the hole. Your head CC's sound very close to mine, I have 2.08"/1.74" valves, and a light mill on 516 heads also. With a .039" gasket, my calculated compression is 9.96/1.
How does it run on the low octane fuel we're forced to use these days? BTW, what pistons do you have in it, and what type of cam? Total advance? Asking nosy questions because I've been out of the motor game for many years. Apologize if questions are out of line. Thanks.
 
which voodoo cam black64?
you can use an Isky tool with the forged pistons
NHRA spec shows .002 out and we made that work
keep the quench tight
you can Ddish those pistons if you really have to
easy to get 5 cc out of the heads-out to the bore size NOT to the gasket ot did you openup around the big valves already?
 
which voodoo cam black64?
you can use an Isky tool with the forged pistons
NHRA spec shows .002 out and we made that work
keep the quench tight
you can Ddish those pistons if you really have to
easy to get 5 cc out of the heads-out to the bore size NOT to the gasket ot did you openup around the big valves already?


the top two hydralic flat tappet cams as mentioned on lunati's web site. I have one in my 440 need the cfm and stall mine is 800cfm and 2800 stall I run a 373 rear.
 
1) You will probably not have a piston to valve problem with the 262 cam
2) at 10.25:1 compression (assumes 0.040" quench), you'll have detonation problems.
3) with the Diamond 51903 piston with valve notches, and 0.050" quench, you'll be at 9.7 for compression. Still might not be pump gas friendly.

Consider ditching the heads. If you do, everything will get better, and not cost you that much more.
 
My work around for the CR, if you’re trying to not change the heads(sounds like they’re already done) would be to use a more old school cam that has more seat timing and a wider lsa.
 
good idea
I think the lunati is 112 lca whereas lots of the others are 110 or even 108
those old heads are heavy
The chamber is similar to the 361-413 Truck head except the truck has a better spark plug placement- wonder why they did not to them all "FE Style"
a Harbor freight grinder and remove some iron
go over .050 on the quench and you might as well go .100
 
Howdy. My first post on here. If you see curiousyellow71 post on here, I am his brother. I thought I would chime in since we have a very similar build going on to this one. It is a 383 .070 over, 440 pistons, ported 516s, 2.08/1.74 valve. Going in a 65 Dart GT with a tight 3600 stall and 3.23s.

We reworked and ported the 516s heads for our build years ago. Using our flow bench we had trouble getting them to flow good with the closed chamber head shrouding the valves. The 2.14s and 1.81s make it that much worse. If they did not unshroud the INTAKE valve. That is something that needs to be done if you want it to run good. Our head are 84cc. That mod alone is probably worth 30 hp on these old heads. At 77cc, my guess is the valves are still shrouded more than they should be.

We are using a Lunati 276/284. Which is actually 279/287 on the cam card. So I would assume a 262 is probably 265. It has a little more seat timing than they advertise it as. FWIW, I think Lunati advertised the shorter timing to compete with comps XEs. Our 383 will have a compression of 9.8. We are milling the piston top down some to get to 9.8. We have a very tight quench though.

I would suggest if you want to run in the upper 9s on the SCR. You need a bigger cam than a 262. The next step, the 268 has the very similar timing events on the intake close and exhaust opening, but has a fair amount more overlap. It will cause pre ignition as bad or worse. The overlap makes it have more power and through basically a similar power band. For compression you have to jump up to the 276/284 to see any improvement. If the 276/284 is to big, I suggest like meantioned above on the earlier post, go “old school” with a slower ramp cam and pick a 112 LSA...
 
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How does it run on the low octane fuel we're forced to use these days? BTW, what pistons do you have in it, and what type of cam? Total advance? Asking nosy questions because I've been out of the motor game for many years. Apologize if questions are out of line. Thanks.

I never ran it a ton, it was thrown together out of junk to prove a point to my brother, a small block Chevy guy. The pistons are the old tech, forged replacement Speed Pros. I never could detect any detonation, even when I forgot to turn on the electric fan, which I did quite often.. The cam was the Summit .465/.488" hydraulic, chosen because it was cheap, and a little bigger than stock, and I really dislike it after using it, no power past mid range, a common complaint I heard about it. I shifted at 5,000 RPMs at the track for my best times, and yes, it had the correct valve springs. Total advance was 35-36 degrees. It did run a 12.3 on it's 3rd pass in an all steel 67 Barracuda, so it wasn't horrible. It would be a good truck motor. :)
 
Howdy. My first post on here. If you see curiousyellow71 post on here, I am his brother. I thought I would chime in since we have a very similar build going on to this one. It is a 383 .070 over, 440 pistons, ported 516s, 2.08/1.74 valve. Going in a 65 Dart GT with a tight 3600 stall and 3.23s.

We reworked and ported the 516s heads for our build years ago. Using our flow bench we had trouble getting them to flow good with the closed chamber head shrouding the valves. The 2.14s and 1.81s make it that much worse. If they did not unshroud the INTAKE valve. That is something that needs to be done if you want it to run good. Our head are 84cc. That mod alone is probably worth 30 hp on these old heads. At 77cc, my guess is the valves are still shrouded more than they should be.

We are using a Lunati 276/284. Which is actually 279/287 on the cam card. So I would assume a 262 is probably 265. It has a little more seat timing than they advertise it as. FWIW, I think Lunati advertised the shorter timing to compete with comps XEs. Our 383 will have a compression of 9.8. We are milling the piston top down some to get to 9.8. We have a very tight quench though.

I would suggest if you want to run in the upper 9s on the SCR. You need a bigger cam than a 262. The next step, the 268 has the very similar timing events on the intake close and exhaust opening, but has a fair amount more overlap. It will cause pre ignition as bad or worse. The overlap makes it have more power and through basically a similar power band. For compression you have to jump up to the 276/284 to see any improvement. If the 276/284 is to big, I suggest like meantioned above on the earlier post, go “old school” with a slower ramp cam and pick a 112 LSA...
Thanks for all the info. I'd be willing to try and unshroud the intakes, but I'm not sure exactly how. Pretty easy to screw it up I imagine. Is there a method for getting it right without poking a carbide burr into the water jacket?
 
The heads we are using are still shrouded and we will be unstrouding them. My brother or I can post some pics as we are doing it if you want to see what it looks like.

Some machine shops can unshroud heads, that is an option if you do not want to do it yourself. Find a competent machine shop that can do it. We have cutters to unshroud heads, but there are some areas for full unshrouding were the head gasket is the limiting to how far the valves can be unshrouded, that has to be done by hand.

Hitting a water jacket isn’t the problem, accidentally nicking a valve seat or head gasket surface is.
 
The heads we are using are still shrouded and we will be unstrouding them. My brother or I can post some pics as we are doing it if you want to see what it looks like.

Some machine shops can unshroud heads, that is an option if you do not want to do it yourself. Find a competent machine shop that can do it. We have cutters to unshroud heads, but there are some areas for full unshrouding were the head gasket is the limiting to how far the valves can be unshrouded, that has to be done by hand.

Hitting a water jacket isn’t the problem, accidentally nicking a valve seat or head gasket surface is.
Pics would be great. There's a bunch of competent machine shops around, but I would like to know whats involved before I start handing out money.
 
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