Heads and cam question
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Heads and cam question I'm looking to get used prc stage 2.5 5.3 heads and ms3 cam used, would the pistons require flycutting for this combo? Can't seem to get an accurate answer. I did read if the ms3 wasn't spec'd for the 5.3 then it would need fly cutting, but how would I know if it was spec'd for the heads? I've read so many answers I don't know which is right. I emailed Texas speed, but they haven't gotten back to me. Could I go with a different cam with the 2.5 5.3 heads that wouldn't require flycutting if so which cam would be best suited for these heads? Would prefer the ms3 though since I can get it used at a good price and people seem to love it with these heads.
What engine will these be on, 5.3? If larger than a 5.3, ignore most of what I said below.
If a 5.3, due to the larger valves with the Stage 2.5 Heads (2.02" Intake/1.575" Exhaust) in a 5.3 Bore 3.78", anything over a 224/224 .580/.580, or around there, generally need the pistons flycut. There may even be some negative affects of the larger valves used in a small bore as well.
The MS3 cam is a Max Effort cam generally used in LS1/6 engines, even some 6.0's. It is going to be a huge cam in a 5.3 and be a dog under 3500 rpm. I would Flycut the pistons or get pistons with valve reliefs.
Will this engine be used in drag racing? If this is a daily I would look more into a 220/224 or 224/224 up to cam.
Others will chime in who are more knowledgeable on this and may recommend you something.
If a 5.3, due to the larger valves with the Stage 2.5 Heads (2.02" Intake/1.575" Exhaust) in a 5.3 Bore 3.78", anything over a 224/224 .580/.580, or around there, generally need the pistons flycut. There may even be some negative affects of the larger valves used in a small bore as well.
The MS3 cam is a Max Effort cam generally used in LS1/6 engines, even some 6.0's. It is going to be a huge cam in a 5.3 and be a dog under 3500 rpm. I would Flycut the pistons or get pistons with valve reliefs.
Will this engine be used in drag racing? If this is a daily I would look more into a 220/224 or 224/224 up to cam.
Others will chime in who are more knowledgeable on this and may recommend you something.
Last edited by 07NBSChevy; Jun 14, 2017 at 01:21 AM.
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This is for an ls1. Car will be a street car and see some canyons as well. Probably take it to the track 4 or 5 times a year just for fun. I would like to get the torque in the 400s though.
Last edited by SSV8; Jun 14, 2017 at 01:37 AM.
Ok, check out this thread. This is a build from Jason (at Texas Speed) LS1 with Stage 2.5 5.3 heads, MS3 Cam, as well as dyno results. Made some good numbers as well.
https://ls1tech.com/forums/dynamomet...o-results.html
Should answer all your questions, no flycutting.
https://ls1tech.com/forums/dynamomet...o-results.html
Should answer all your questions, no flycutting.
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I dont forsee 400 tq with those heads. Maybe with afr 205s. The 220 224 cam will be great for canyons, should make torque everywhere and doesnt need much converter to run right. The streetsweeper TQ by Ed Curtis will make more power then the comp.
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indeed. I wouldnt go any bigger, you don't want to have to wind it up to 4500 to make power over a canyon. I know lots of people who usethe eps cam for circuit track and they love it. Make sure you build suspension too.
Not just tq is needed but also a stable marine style lobe as well. You can just throw some catchy name cam at a setup like that and be optimized. I would use the HUC lobes as they are higher lift marine style stable lobe that work well with any valve and are made for sustained rpm esp mid range. They make great power and are a better design than alot lf the similar @.050 cams and lobes out there.
The ms3 isnt max effort although it is considered close, its more of a peaky higher rpm cam that like most said will sacrifice the power where youd want it.
Id recommend a 223/231 on huc lobes in the 113+2 lsa/icl area , run a dual spring and an 11/32nd manton pushrod and be done with it. most people will recommend a ti retainer, but you can use either honestly ti or tool steel.
The ms3 isnt max effort although it is considered close, its more of a peaky higher rpm cam that like most said will sacrifice the power where youd want it.
Id recommend a 223/231 on huc lobes in the 113+2 lsa/icl area , run a dual spring and an 11/32nd manton pushrod and be done with it. most people will recommend a ti retainer, but you can use either honestly ti or tool steel.
Last edited by tech@WS6store; Jun 14, 2017 at 01:06 PM.
No fly cutting.
A smaller cam like that wouldnt fare too well in roll racing, maybe some more exh duration and a 227 intake dur and prob a 235 exhaust which is a"normal stage "x" cam" spec just on lobes designed for sustained rpm for road racing. add some 390s or 410s and you would have a better time on the roll races. Its not going to pull super high with an ls6 intake maybe 6300 or so, a fast 92 or 102 would add about 100 to 300 rpm to that prob. thats as big as i would go though.
That would still be a good road race cam but have a better time roll racing with a manual and youd see quite a bit of power on say 100shot of nitrous also.
A smaller cam like that wouldnt fare too well in roll racing, maybe some more exh duration and a 227 intake dur and prob a 235 exhaust which is a"normal stage "x" cam" spec just on lobes designed for sustained rpm for road racing. add some 390s or 410s and you would have a better time on the roll races. Its not going to pull super high with an ls6 intake maybe 6300 or so, a fast 92 or 102 would add about 100 to 300 rpm to that prob. thats as big as i would go though.
That would still be a good road race cam but have a better time roll racing with a manual and youd see quite a bit of power on say 100shot of nitrous also.
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You cant build a car that excels from a dig, canyons and from a roll. Since its a street car build it as a street car and just enjoy it. I'd get a cam with a nice flat torque curve with stable lobes like Ws6 said and a good set of heads to match.
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I'm aiming at building a car that does ok in everything rather then excel at one thing. I think I'm going to call a couple vendors and look for something with a flat torque curve like you said. What do you guys think between prc 2.5 5.3 heads compared to livernois stage 2 243s?
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I'm aiming at building a car that does ok in everything rather then excel at one thing. I think I'm going to call a couple vendors and look for something with a flat torque curve like you said. What do you guys think between prc 2.5 5.3 heads compared to livernois stage 2 243s?
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well I'm looking to get used heads and the prc and livernois stage 2 243s are about the same price which is why I brought it up. I've read tons of good info on the prc, but not as much info on livernois, though I did read some and it seems the livernoise heads seem to bring out a little more power then the prc heads. I will look into that eps cam. I like the fact that it won't drone as well since I am already going deaf. I've also read the tr224 is a real good street cam with a linear power band, any thoughts on this cam? Would a cam that has some lope to it drown out my ears? I wanted a little lope, but I don't want to deal with the drone when taking 8 hour rides.
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well I'm looking to get used heads and the prc and livernois stage 2 243s are about the same price which is why I brought it up. I've read tons of good info on the prc, but not as much info on livernois, though I did read some and it seems the livernoise heads seem to bring out a little more power then the prc heads. I will look into that eps cam. I like the fact that it won't drone as well since I am already going deaf. I've also read the tr224 is a real good street cam with a linear power band, any thoughts on this cam? Would a cam that has some lope to it drown out my ears? I wanted a little lope, but I don't want to deal with the drone when taking 8 hour rides.
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OP should call and talk about building a package from you guys, heads cam and all the necesseary accessories....of course I would call multiple vendors like Brian tooley racing, Texas speed etc etc. See who will give you a better deal.