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1991 corvette 383 stoker needs cam

Old 11-07-2018, 11:39 AM
  #21  
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I carbed my 84 decades ago. Used a low profile Weiand dual plane and a dropped base air filter. No hole in hood needed.
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Old 11-07-2018, 12:21 PM
  #22  
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Originally Posted by MatthewMiller View Post
I wish I had an encyclopedic knowledge of the parts out there like some others do. That said, I looked up your quoted cam and there are two interesting things about. First, the LSA on the Lunati site is 112, not 110. Also, their advertised duration is not as high as I was expecting: only 278/288. For a 383 with stock heads, that might not be a bad choice. It's clearly intended for stock heads, given the "Retro-Fit" moniker and the low lift, and they quote a speed range of 2000-6400. I sort of assume they mean that for a 350, so it would be a bit lower for a 383.

If I were you, I'd call Lunati and ask them a few questions. First, tell them your parameters (383, stock heads and valvetrain, could get new t/c, your max desired rpm, etc.), and ask them if this cam makes sense for your build. Will they endorse it for your stock valve springs and rockers? What do they recommend? The other obvious one to consider is the [color=justify=#000000]20120120, which is very close in advertised duration and lift, but significantly less on duration at .050". It would have less overlap and a better idle, but it might be too little to let a 383 breathe above 5000rpm.[/color]
I called Lunati and asked what they thought of my cam choose and the guy said it would be good for my car. He told me to get the 20080131 cam, it is the same thing but will work in my car . He said somthing about the other cam being a retro fit. So I think Iím going to go with the 20080131 cam. What do you think?
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Old 11-07-2018, 03:44 PM
  #23  
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Originally Posted by Lanceangle View Post
I called Lunati and asked what they thought of my cam choose and the guy said it would be good for my car. He told me to get the 20080131 cam, it is the same thing but will work in my car . He said somthing about the other cam being a retro fit. So I think Iím going to go with the 20080131 cam. What do you think?
I'm not totally sure what the differences between the 20120121 and this 20080131 are. The latter appears to be intended for LT engines, not an L98. According to this thread, there are differences in the dowel pin, the hole in front, and maybe the distributor and oil pump gear. I hope someone else can chime in here, but I'm thinking that for an L98 you want the Retro Fit cam (20120121) for an L98.

As for the actual grind on the lobes, yes they are the same. If Lunati says it will do what you want it to do, then I'd go for it. Make sure you get whatever springs they want you to use with it. They say it "likes a 2200rpm stall converter." That might actually be within your stock t/c's stall speed. You can certainly try it with your stock t/c and see what it's like. You may decide to go a step higher in stall speed after that...or not.
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Old 11-07-2018, 05:16 PM
  #24  
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The dowl pin in the cam drives opti and is a 1/4" longer in the 94 b body and 95-97 LTx engines. If 92-94 F body or Corvette is converted to the gen2 opti the dowl needs to be changed to the 1/4" longer type. The splined early opti engine 92-94 can use the sbc cams. To install " hot cam" in the earlier engine, the longer dowl pin has to be changed to the shorter standard pin.
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Old 11-07-2018, 05:50 PM
  #25  
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I don't see the logic in that 20080131 cam choice or the previous, the duration at 050 is too high. It would basically be undriveable on the street to get to the track. I'd only go that big a cam with a 398 or 409 or something bigger than a 383, and even then I'd treat it as a 100% race car and wouldn't be driving around town, you'd have to run pig rich and the damn thing will probably cut off at every stop light.

I'd go with something more in the realm of 220-230 @050, but not over 240 on the exhaust side. The rec made above of 224/230 is more of what I'm thinking.

In any case its a mismatch for the heads, which can only support about 350hp unported. You can port 113s heavily to make them hold up to 400, but not really any further. This cam choice, plus a 383, warrants 190cc heads at a minimum. Preferably bigger than that, 195-210cc.

A 91 has a wimpy 1500rpm TC, and this combo will need a min of 2200-2400. The dragsters here will probably run more stall than that too, but streetability suffers when you go over 2400-2800 in my opinion, but that is a subjective thing to many.

You will not be able to use slicks with the D36. You must upgrade to D44 rear axle.

You have a lot of stuff that needs to be done here to make this into a race car. Plan this out some more.
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Old 11-07-2018, 05:59 PM
  #26  
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Originally Posted by Kevova View Post
The dowl pin in the cam drives opti and is a 1/4" longer in the 94 b body and 95-97 LTx engines. If 92-94 F body or Corvette is converted to the gen2 opti the dowl needs to be changed to the 1/4" longer type. The splined early opti engine 92-94 can use the sbc cams. To install " hot cam" in the earlier engine, the longer dowl pin has to be changed to the shorter standard pin.
so do any of the 2 cams I suggested work for my car? I donít understand exactly what you are saying
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Old 11-07-2018, 06:30 PM
  #27  
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The 20080131 is for a LT1 I would just stick with a SBC 55-95.
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Old 11-07-2018, 07:58 PM
  #28  
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Originally Posted by Kevova View Post
The 20080131 is for a LT1 I would just stick with a SBC 55-95.
well the only difference between an L 98 in an LT one is that the LT one had reversed cooling and I didnít have a distributor and had something else right. Do you think it would really make that much of a difference? I just called Jegs to see what they said about the Cam and they said it would be good for my car
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Old 11-07-2018, 08:09 PM
  #29  
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The cams are similar. The dowl pin could be an issue. The LT1 cam dowl pin for the later 94-97 engine will contact SBC timing cover. Just keep it simple you have a SBC ; specify a cam for a SBC.
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Old 11-07-2018, 08:49 PM
  #30  
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Its easy to cut the dowel pin to make it work. Some cams have a deep hole and you just tap it in deeper. Some LT cams do not have the lobe for a mechanical fuel pump but that should not be an issue here.
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Old 11-08-2018, 06:06 PM
  #31  
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So I think the plan is to get the 20080131 cam with 73943-16 valve springs, everything would just go right in with now problems right? Thank you for all the help iv got from everyone
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Old 11-08-2018, 07:04 PM
  #32  
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Originally Posted by Lanceangle View Post
So I think the plan is to get the 20080131 cam with 73943-16 valve springs, everything would just go right in with now problems right? Thank you for all the help iv got from everyone
Again, for an L98 (which is still a Gen 1 SBC), I think you'd want the 20120121. You can make the 20080131 work, but you would have to mess with the dowel pin on the front to clear the timing cover. I can't think of a good reason to use an LTx cam in an L98 engine. Call Lunati back and verify that, though.
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Old 11-08-2018, 10:54 PM
  #33  
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Originally Posted by MatthewMiller View Post
Again, for an L98 (which is still a Gen 1 SBC), I think you'd want the 20120121. You can make the 20080131 work, but you would have to mess with the dowel pin on the front to clear the timing cover. I can't think of a good reason to use an LTx cam in an L98 engine. Call Lunati back and verify that, though.
yea I will call them back to verify, but when I called them they told me I should get the 20080131 instead of the 20120121 because the 20120121 is a retrofit cam made for a block that is not a factory hydraulic roller cam and you make the block a hydraulic roller. I will call again but he told me to get the 20080131 over the 20120121 because the 20120121 is a retro fit and he said I would have to change some of the belts and pullies and stuff like that. Idk for sure but thatís just what he told me.
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Old 11-08-2018, 11:50 PM
  #34  
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Originally Posted by Lanceangle View Post
yea I will call them back to verify, but when I called them they told me I should get the 20080131 instead of the 20120121 because the 20120121 is a retrofit cam made for a block that is not a factory hydraulic roller cam and you make the block a hydraulic roller. I will call again but he told me to get the 20080131 over the 20120121 because the 20120121 is a retro fit and he said I would have to change some of the belts and pullies and stuff like that. Idk for sure but thatís just what he told me.
I may be missing something, but needing to change belts and pulleys because of a cam change doesn't make sense to me. When you call them, make 100% sure they understand that your engine is an L98 (a Gen 1 SBC), and not an LT1. Let us know what they say, and how it goes.
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Old 11-09-2018, 04:26 AM
  #35  
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Maybe the 20120121 cam is missing step nose which is required for a cam thrust plate on the front of the roller cam block?



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Old 11-09-2018, 08:27 AM
  #36  
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Originally Posted by Paccanini View Post
Maybe the 20120121 cam is missing step nose which is required for a cam thrust plate on the front of the roller cam block?

yea Iím not sure, Iím going to call them today to cheak 100% for sure what I need
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Old 11-09-2018, 10:57 AM
  #37  
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Originally Posted by MatthewMiller View Post
I may be missing something, but needing to change belts and pulleys because of a cam change doesn't make sense to me. When you call them, make 100% sure they understand that your engine is an L98 (a Gen 1 SBC), and not an LT1. Let us know what they say, and how it goes.
OK so I just got off the phone with Lunati again and they did verify that the 20080131 Cam would work in my car and the 20120121 Cam I would have to change my thruster plate and timing chain and something else . They also said the Dowl Penn wouldnít be a problem
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Old 11-09-2018, 10:59 AM
  #38  
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Originally Posted by Lanceangle View Post

OK so I just got off the phone with Lunati again and they did verify that the 20080131 Cam would work in my car and the 20120121 Cam I would have to change my thruster plate and timing chain and something else . They also said the Dowl Penn wouldn’t be a problem
Gotcha. So Paccanini called it correctly, and I was missing something. Thanks.

Last edited by MatthewMiller; 11-09-2018 at 11:00 AM.
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Old 11-11-2018, 11:16 PM
  #39  
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Originally Posted by MatthewMiller View Post
Gotcha. So Paccanini called it correctly, and I was missing something. Thanks.
I have another question and I didnít know if you could help me out, how much power do you think my stock l98 aluminum heads can hold? Do you think I would be losing a lot of power because of them? I saw someone said they can only hang 350hp, do you think that how much they can handle?
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Old 11-11-2018, 11:19 PM
  #40  
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Originally Posted by vader86 View Post
I don't see the logic in that 20080131 cam choice or the previous, the duration at 050 is too high. It would basically be undriveable on the street to get to the track. I'd only go that big a cam with a 398 or 409 or something bigger than a 383, and even then I'd treat it as a 100% race car and wouldn't be driving around town, you'd have to run pig rich and the damn thing will probably cut off at every stop light.

I'd go with something more in the realm of 220-230 @050, but not over 240 on the exhaust side. The rec made above of 224/230 is more of what I'm thinking.

In any case its a mismatch for the heads, which can only support about 350hp unported. You can port 113s heavily to make them hold up to 400, but not really any further. This cam choice, plus a 383, warrants 190cc heads at a minimum. Preferably bigger than that, 195-210cc.

A 91 has a wimpy 1500rpm TC, and this combo will need a min of 2200-2400. The dragsters here will probably run more stall than that too, but streetability suffers when you go over 2400-2800 in my opinion, but that is a subjective thing to many.

You will not be able to use slicks with the D36. You must upgrade to D44 rear axle.

You have a lot of stuff that needs to be done here to make this into a race car. Plan this out some more.
do you really only think the heads can only hold 350hp? How much would I have to port them to hold more?
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