400ci+ LT1 (yea I know again)
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Joined: Jan 2003
Posts: 1,064
From: Dobson, NC
400ci+ LT1 (yea I know again)
I wanna build a 400+ ci. Whats the best clearing crank, rods, and pistons to use. I wanna use a callies magnum XL crank, but if there is something that will provide extra clearence that will be fine. I know there isnt much more of a gain over a 396 but what the heck I like being unique. What parts do I need to make grinding a minimum?
TIA
TIA
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Joined: Jul 2001
Posts: 752
From: Double Oak TX
I wanna build a 400+ ci. Whats the best clearing crank, rods, and pistons to use. I wanna use a callies magnum XL crank, but if there is something that will provide extra clearence that will be fine. I know there isnt much more of a gain over a 396 but what the heck I like being unique. What parts do I need to make grinding a minimum?
TIA
TIA
Usually where there is a market there is a way; but being commercial offerings have completely disappeared, I would assume it's not a market issue, but "way" issue. I do remember Jorden Musser cracked his block after going to a .060 overbore.
Hey...work it out and share as I believe there is a little more too it hand just clearancing.
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Joined: Jan 2003
Posts: 1,064
From: Dobson, NC
So which rods and crank would require less clearence? Oliver? Carrillo? Callies? Im thinking 4.00 stroke with a 4.030 bore. It will be a year or two before its complete, but Im gonna buy the absolute best reguardless of the price.
Would a 2-bolt be better than a 4-bolt on the clearencing part? Or would you run the 4-bolt for strength?
As far as heads a set of the big afr's ported out wouldnt do the job?
Would a 2-bolt be better than a 4-bolt on the clearencing part? Or would you run the 4-bolt for strength?
As far as heads a set of the big afr's ported out wouldnt do the job?
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Joined: Dec 1969
Posts: 10,745
From: Buffalo, New York
The head issue is that the minimum cross section of LTx style heads is generally too small to support a high hp, big cube motor. The way to compensate is to use a cam with very aggressive ramps, but that is a band-aid which in turn introduces the need for high end valve train parts carefully selected and assembled. Still compared to the same heads as on a smaller motor it will make more torque and power up to high rpm, where it won't make any less. That is the best rationale for a street stroker in the first place. It's just that the added cost and difficulty of going that big on a production block leads most people to a 383 or 396.
As far as clearance, the issue is going to be with the rods. The best I have seen are the Oliver billets, but they run $1,200/set and are overkill for this relatively low rpm, non-power adder setup. Lunati "Pro-Mod" are a very nice rod with excellent clearance for ~$700/set. I'd use them.
As I alluded to above, in the context of LTx heads, you want the ports with the biggest CSA you can get. This motor will want a lot of air. The best LTx choice would be the AFR 220 or 227. You will need shaft mounts if you go with these. Once you have the heads, you need to size the cam (duration) to match the max rpm the heads will support. The LSA should then be chosen for the desired overlap - probably something in the 106-108 degree range. Then, go for aggressive lobes with high ratio rockers and lift in the 0.625-0.650" range. You want the high ratio rockers both for the added valve acceleration and to keep the lobes small relative to the lift for clearance purposes. In any case, you may need a small base circle cam. And so it goes - component selection is going to be critical and assembly will require a sharp eye, lots of care, and a lot of time. Needless to say, this is going to require a custom cam to work to its' potential.
Getting the most out of a motor like this is a challenge, even more so than the standard setup. If you really want it to scream, have a set of heads converted. This, of course, adds to the cost and complexity. Of course, if you go this route you will then also need a manifold and TB setup if you decide to adapt non-LTx heads. And so on wrt cost and complexity. Lots of compromises to consider. To get the most out of it, I recommend working closely with someone who understands motors. Don't get me wrong, if you just bolt together a set of parts that would work well on a 383 it will work, and work pretty good but will not in any way be worth it. If you want to get the most out of it, you will need cubic brains more than anything else.
And yes, get a 4-bolt setup. This will not make clearance any more difficult.
And one more thing, do a partial block fill. This will be all to the good for a variety of reasons including giving you some leeway if you hit the water jacket trying to get the clearance you need.
Rich
As far as clearance, the issue is going to be with the rods. The best I have seen are the Oliver billets, but they run $1,200/set and are overkill for this relatively low rpm, non-power adder setup. Lunati "Pro-Mod" are a very nice rod with excellent clearance for ~$700/set. I'd use them.
As I alluded to above, in the context of LTx heads, you want the ports with the biggest CSA you can get. This motor will want a lot of air. The best LTx choice would be the AFR 220 or 227. You will need shaft mounts if you go with these. Once you have the heads, you need to size the cam (duration) to match the max rpm the heads will support. The LSA should then be chosen for the desired overlap - probably something in the 106-108 degree range. Then, go for aggressive lobes with high ratio rockers and lift in the 0.625-0.650" range. You want the high ratio rockers both for the added valve acceleration and to keep the lobes small relative to the lift for clearance purposes. In any case, you may need a small base circle cam. And so it goes - component selection is going to be critical and assembly will require a sharp eye, lots of care, and a lot of time. Needless to say, this is going to require a custom cam to work to its' potential.
Getting the most out of a motor like this is a challenge, even more so than the standard setup. If you really want it to scream, have a set of heads converted. This, of course, adds to the cost and complexity. Of course, if you go this route you will then also need a manifold and TB setup if you decide to adapt non-LTx heads. And so on wrt cost and complexity. Lots of compromises to consider. To get the most out of it, I recommend working closely with someone who understands motors. Don't get me wrong, if you just bolt together a set of parts that would work well on a 383 it will work, and work pretty good but will not in any way be worth it. If you want to get the most out of it, you will need cubic brains more than anything else.
And yes, get a 4-bolt setup. This will not make clearance any more difficult.
And one more thing, do a partial block fill. This will be all to the good for a variety of reasons including giving you some leeway if you hit the water jacket trying to get the clearance you need.
Rich
Last edited by rskrause; May 12, 2007 at 02:40 AM.
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Joined: Jun 2004
Posts: 411
I think Rich covered it pretty well 
I would get a set of All-pros and convert them if you are at all serious. If you are going to a single plane this makes it very easy and the cost of conversion is about 400 bucks. This way no conversion is needed for the intake you can run a off the shelf SBC manifold.
If your going through all the hassel of this though why not move the cam up in the block .100? It would give you a little extra clearance and might make things fit a little easier. It would be pretty exspensive and I'm not sure if it can even be done. The lifters and everything would have to be relocated as well. I would guess this procesure to be atleast a grand. But you gotta pay to play.
I would get a set of All-pros and convert them if you are at all serious. If you are going to a single plane this makes it very easy and the cost of conversion is about 400 bucks. This way no conversion is needed for the intake you can run a off the shelf SBC manifold.
If your going through all the hassel of this though why not move the cam up in the block .100? It would give you a little extra clearance and might make things fit a little easier. It would be pretty exspensive and I'm not sure if it can even be done. The lifters and everything would have to be relocated as well. I would guess this procesure to be atleast a grand. But you gotta pay to play.
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Joined: Dec 1969
Posts: 10,745
From: Buffalo, New York
Just re-read my above post - EXCELLENT! So as not to mess up the flow and syntax of it, just to make one other point. The hot ticket in a big inch small block is a big bore setup as alluded to in a previous post. The way to do this is with an aftermarket Gen I block such as the Dart Little M. A 4.185" bore and 3.750" stroke gives 412ci and with a set of Dart Pro 1 or equivalent heads can make over 600hp at a conservative 6,600-6,700rpm, no problem. Just select nitrous friendly pistons and add a 150hp shot or so and you will be in the low nines in a properly set up 3,600lb car.
All it takes is money and desire!
Rich
All it takes is money and desire!
Rich
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Joined: Dec 1969
Posts: 10,745
From: Buffalo, New York
I am on a roll, so just to go with it a little more, some further insomniac thoughts. The problem is that we are dealing with a relatively "undervalved" engine when speaking of strokers. Especially NA setups on stock blocks - there is only so much valve you can fit in the relatively small bore. This has a huge impact on optimal cam specs.
Rich
Rich
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Joined: Jul 2001
Posts: 752
From: Double Oak TX
The head issue is that the minimum cross section of LTx style heads is generally too small to support a high hp, big cube motor. The way to compensate is to use a cam with very aggressive ramps, but that is a band-aid which in turn introduces the need for high end valve train parts carefully selected and assembled. Still compared to the same heads as on a smaller motor it will make more torque and power up to high rpm, where it won't make any less. That is the best rationale for a street stroker in the first place. It's just that the added cost and difficulty of going that big on a production block leads most people to a 383 or 396.
As far as clearance, the issue is going to be with the rods. The best I have seen are the Oliver billets, but they run $1,200/set and are overkill for this relatively low rpm, non-power adder setup. Lunati "Pro-Mod" are a very nice rod with excellent clearance for ~$700/set. I'd use them.
As I alluded to above, in the context of LTx heads, you want the ports with the biggest CSA you can get. This motor will want a lot of air. The best LTx choice would be the AFR 220 or 227. You will need shaft mounts if you go with these. Once you have the heads, you need to size the cam (duration) to match the max rpm the heads will support. The LSA should then be chosen for the desired overlap - probably something in the 106-108 degree range. Then, go for aggressive lobes with high ratio rockers and lift in the 0.625-0.650" range. You want the high ratio rockers both for the added valve acceleration and to keep the lobes small relative to the lift for clearance purposes. In any case, you may need a small base circle cam. And so it goes - component selection is going to be critical and assembly will require a sharp eye, lots of care, and a lot of time. Needless to say, this is going to require a custom cam to work to its' potential.
Getting the most out of a motor like this is a challenge, even more so than the standard setup. If you really want it to scream, have a set of heads converted. This, of course, adds to the cost and complexity. Of course, if you go this route you will then also need a manifold and TB setup if you decide to adapt non-LTx heads. And so on wrt cost and complexity. Lots of compromises to consider. To get the most out of it, I recommend working closely with someone who understands motors. Don't get me wrong, if you just bolt together a set of parts that would work well on a 383 it will work, and work pretty good but will not in any way be worth it. If you want to get the most out of it, you will need cubic brains more than anything else.
And yes, get a 4-bolt setup. This will not make clearance any more difficult.
And one more thing, do a partial block fill. This will be all to the good for a variety of reasons including giving you some leeway if you hit the water jacket trying to get the clearance you need.
Rich
As far as clearance, the issue is going to be with the rods. The best I have seen are the Oliver billets, but they run $1,200/set and are overkill for this relatively low rpm, non-power adder setup. Lunati "Pro-Mod" are a very nice rod with excellent clearance for ~$700/set. I'd use them.
As I alluded to above, in the context of LTx heads, you want the ports with the biggest CSA you can get. This motor will want a lot of air. The best LTx choice would be the AFR 220 or 227. You will need shaft mounts if you go with these. Once you have the heads, you need to size the cam (duration) to match the max rpm the heads will support. The LSA should then be chosen for the desired overlap - probably something in the 106-108 degree range. Then, go for aggressive lobes with high ratio rockers and lift in the 0.625-0.650" range. You want the high ratio rockers both for the added valve acceleration and to keep the lobes small relative to the lift for clearance purposes. In any case, you may need a small base circle cam. And so it goes - component selection is going to be critical and assembly will require a sharp eye, lots of care, and a lot of time. Needless to say, this is going to require a custom cam to work to its' potential.
Getting the most out of a motor like this is a challenge, even more so than the standard setup. If you really want it to scream, have a set of heads converted. This, of course, adds to the cost and complexity. Of course, if you go this route you will then also need a manifold and TB setup if you decide to adapt non-LTx heads. And so on wrt cost and complexity. Lots of compromises to consider. To get the most out of it, I recommend working closely with someone who understands motors. Don't get me wrong, if you just bolt together a set of parts that would work well on a 383 it will work, and work pretty good but will not in any way be worth it. If you want to get the most out of it, you will need cubic brains more than anything else.
And yes, get a 4-bolt setup. This will not make clearance any more difficult.
And one more thing, do a partial block fill. This will be all to the good for a variety of reasons including giving you some leeway if you hit the water jacket trying to get the clearance you need.
Rich
Man, this list is on a real roll. It is incrediable the difference in depth and substance this list supports vs the C4 list. Damn, what is up with those people?? Still think hot cams and TPIS stuff is the hot setup while still holding on to ignorant wife's tales on dumb stuff.
Glad I'm here to enjoy the show. Thanks!!
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Joined: Jun 2003
Posts: 3,557
From: Carol Stream, Il.
Outstanding post Rich.
Man, this list is on a real roll. It is incrediable the difference in depth and substance this list supports vs the C4 list. Damn, what is up with those people?? Still think hot cams and TPIS stuff is the hot setup while still holding on to ignorant wife's tales on dumb stuff.
Glad I'm here to enjoy the show. Thanks!!
Man, this list is on a real roll. It is incrediable the difference in depth and substance this list supports vs the C4 list. Damn, what is up with those people?? Still think hot cams and TPIS stuff is the hot setup while still holding on to ignorant wife's tales on dumb stuff.
Glad I'm here to enjoy the show. Thanks!!
Thread Starter
Registered User
Joined: Jan 2003
Posts: 1,064
From: Dobson, NC
Aight a recap, The brand of crank doesnt matter so I really want to run the Callies Magnum XL, Rods needs to be a oliver billet, Heads a worked AFR 227, and small circle base. Does the cam need to be crazy big or can I run a nice mild HYD roller?