243 head questions
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Teching In
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243 head questions Hey, I am going to be building a big CID engine using an aluminum 6.0 or 6.2 block and I'm going to be using it as a race engine. I just bought a pair of 243's from a member on here and I want to know what I should use for springs and rockers because I am hoping for a lot of hp. And yes, I will be porting the heads. I'm just trying to figure out the best route to go about this. Any help would be great, thank you.
Trev
Trev
There are better head choices then the 243's. My choice would be the PAC springs 1518,1521 look them up on their site. Alot of people run the patriot golds.
Stock rebuilt rockers are fine as well as the stock GM LS6 valves. Ran the 243's for many years they developed small cracks on the intake throat ,and leaked water into the engine. I had them repaired and sold them.
The Ls3 heads or an aftermarket casting would be better then a 43 head.IMOP.
Stock rebuilt rockers are fine as well as the stock GM LS6 valves. Ran the 243's for many years they developed small cracks on the intake throat ,and leaked water into the engine. I had them repaired and sold them.
The Ls3 heads or an aftermarket casting would be better then a 43 head.IMOP.
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Teching In
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I will be porting them in head class at SAM.
I have looked up some of the aluminum type rockers like the patriot golds and some others. is PAC the name of the company or does it stand for something?
I would go aftermarket on the heads, but I figured I could still get some flow out of these 243s by porting. Haven't heard of them cracking in the intake throat. That's interesting.
I'm still trying to decide whether to rebuild stock rockers, or go with some patriot golds.
Thanks for the help guys.
I have looked up some of the aluminum type rockers like the patriot golds and some others. is PAC the name of the company or does it stand for something?
I would go aftermarket on the heads, but I figured I could still get some flow out of these 243s by porting. Haven't heard of them cracking in the intake throat. That's interesting.
I'm still trying to decide whether to rebuild stock rockers, or go with some patriot golds.
Thanks for the help guys.
I will be porting them in head class at SAM.
I have looked up some of the aluminum type rockers like the patriot golds and some others. is PAC the name of the company or does it stand for something?
I would go aftermarket on the heads, but I figured I could still get some flow out of these 243s by porting. Haven't heard of them cracking in the intake throat. That's interesting.
I'm still trying to decide whether to rebuild stock rockers, or go with some patriot golds.
Thanks for the help guys.
I have looked up some of the aluminum type rockers like the patriot golds and some others. is PAC the name of the company or does it stand for something?
I would go aftermarket on the heads, but I figured I could still get some flow out of these 243s by porting. Haven't heard of them cracking in the intake throat. That's interesting.
I'm still trying to decide whether to rebuild stock rockers, or go with some patriot golds.
Thanks for the help guys.
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Thread Starter
Teching In
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I am now changing to iron block and going to bore .060 over, still undecided on efi, or carb. But I know I want at least 600 hp, (if that's possible).
Thanks!
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Where would I get some bearings for the stockers? I looked on PAC and when I tried to open the page with drag springs and ls springs, some of the pages wouldn't load with results?
I am now changing to iron block and going to bore .060 over, still undecided on efi, or carb. But I know I want at least 600 hp, (if that's possible).
Thanks!
I am now changing to iron block and going to bore .060 over, still undecided on efi, or carb. But I know I want at least 600 hp, (if that's possible).
Thanks!
Bearings for the rockers come in the truinion upgrade kits sold by many of the sponsors. Harland Sharp and Comp both make them.
Not enough info provided for anybody to help out with a spring choice but thinking just a good stout dual will more than likely work well.
Where would I get some bearings for the stockers? I looked on PAC and when I tried to open the page with drag springs and ls springs, some of the pages wouldn't load with results?
I am now changing to iron block and going to bore .060 over, still undecided on efi, or carb. But I know I want at least 600 hp, (if that's possible).
Thanks!
I am now changing to iron block and going to bore .060 over, still undecided on efi, or carb. But I know I want at least 600 hp, (if that's possible).
Thanks!
Show me one. I haven't seen any myself yet. BSE built a 434 and it made in the 7's on an engine dyno with $$$ parts. It was a year or 2 ago. Things may have changed. They were runner up in the Engine Masters Challenge with that build.
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I've been told by some people here at the school that it shouldn't be too hard to make 650+ hp with a nice big cam.
Also the situation changed and I'm just going to bore it .030 over and put a 4" stroke crank in it which will make it a 408 CID.
With those 243 heads I will have to put in bigger valves and port. Any idea on how big of valves you can put in 243's?
Also the situation changed and I'm just going to bore it .030 over and put a 4" stroke crank in it which will make it a 408 CID.
With those 243 heads I will have to put in bigger valves and port. Any idea on how big of valves you can put in 243's?
Dude seriously its going to take more than that to make 650+. You will never reach that on the factory cast 243's. You are going to have to run some afr or trick flow heads or something. I wouldn't listen to your buddies at school.
I've been told by some people here at the school that it shouldn't be too hard to make 650+ hp with a nice big cam.
Also the situation changed and I'm just going to bore it .030 over and put a 4" stroke crank in it which will make it a 408 CID.
With those 243 heads I will have to put in bigger valves and port. Any idea on how big of valves you can put in 243's?
Also the situation changed and I'm just going to bore it .030 over and put a 4" stroke crank in it which will make it a 408 CID.
With those 243 heads I will have to put in bigger valves and port. Any idea on how big of valves you can put in 243's?
A 408 is going to be hard pressed to make 550 let alone 650. Its gonna take more cubes and LS7 heads if you stay with a GM castings. It might make 600.
Like I posted above a 434 with PI heads and intake ( now Mast) only made 713FWHP which say taking away 16-20% for a chassis dyno equals 599 to 571RWHP.
The 243's are a nice head if you have them already but 450 should be your goal. It's not worth doing alot of work to them like changing valve sizes etc. Porting them would be good if you can get it done cheap. Don't get me wrong I like running factory castings the 92's that I'm running now have 2500.00 in them. That includes the price of the bare castings , valves, seals , and porting. There are better heads out now for that kind of money. Good luck with what ever you build.
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I don't know how long I will use these heads. I'm getting ready to go back to the school to have someone flow them to see what cfm they flow.
I know a guy with a 377 CID back home that built a big cam engine that made 704 hp on the engine dyno. His heads flow 340 cfm.
Like I said, I'm going to port the heads and see what cfm I can get out of them. I will let you all know how much my heads flow later on.
I will keep you all updated too.
I know a guy with a 377 CID back home that built a big cam engine that made 704 hp on the engine dyno. His heads flow 340 cfm.
Like I said, I'm going to port the heads and see what cfm I can get out of them. I will let you all know how much my heads flow later on.
I will keep you all updated too.
