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  #31 (permalink)  
Old 12-05-2012, 05:00 PM
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Quote:
Originally Posted by ap72 View Post
I was saying that you can't look at the duration as you would with a hydraulic flat tappet cam. For a hyd flat cam that .050" duration is pretty damn big for a street car, BUT when you factor in the lash on a solid cam and the more agressive lobes of a roller cam that duration really isn't that big of a deal. The drivability will compare with a hyd flat cam with duration in the 230's and as we all know- that's pretty typical for a mild "hot street" 454.

I'm not saying it's an RV cam but it's not as rowdy as you might think. It's about 20-30 degrees short of a full solid roller race cam.
yeah i didnt think that duration was very wild for the street, the lift maybe

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  #32 (permalink)  
Old 12-06-2012, 08:36 AM
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too much or not enough motor

Quote:
Originally Posted by hcompton View Post
Its a big block that cam is not that big. For a small block maybe but for big block its just normal big not high rpm.

@cdminter59 2800 - 7000 rpm range with a 454. What?? no not that high rpm and the big block will make some good power down low. Did you miss where he said its a 454 bored 60 over. that is a large piston it will take a pretty big cam.

It will be pretty tame since the car is very light and the motor will make alot of tq down low it will pull away from lights gently enough. Engine probably wont even notice the car is connected. But have you thought about an auto. th700r4 would be a much better choice than the muncie. If its numbers matching then pull it and set it aside. The big block will break it for sure at some point if you drive it long enough. Also the auto will be a half second faster in the quarter. Maybe more since you will loose tracktion alot with the big block and heavy clutch.
hcompton, I stated the operating rpms of the Lunati camshaft he has. Solid Roller Street/Strip 2800 - 7000 249/255 .663"/.680" 110/106 40110733. I said he would need a low enough rear end that when cruising at 55-60 mph he would be taching 3000-3500 rpms.
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  #33 (permalink)  
Old 12-06-2012, 08:52 AM
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Quote:
Originally Posted by hcompton View Post
Not all bbc heads are bad flowing heads. Bbc was made years after the small block and chevy addressed a lot of the flow issues the small block had with the larger boore big blocks.

I agree its not worth the money or time to port small block heads. Aftermarket heads are so cheap. But maybe not bad idea with bbc heads since there are no real cheap options. Might be worth the cash to get them cut by a pro. Depends if you got someone that can port at a good price.

Larger ports do not grant blessed more air/fuel into the cylinder. Most of the time the opposite is true.

Throat size? Throttle plate? Rare to get turbulence in the carb do to high flow rate. Usally that can be seen with a vacum guage at wot. Single and dual plane intakes really remove most of the issues that could result in engines that have very long tuned single runner intakes. In the big chevy were only talking about single runner for a few inches. Well past the carb.

Valve seat? You mean valve size as measured at the seat? Or the seat insert itself. It should be cut back if bored to larger valve if it came from the factory with larger valves then it is already taken care of. If you talking about bad machine work. I would hope that is not going to be an issue.

The reason you rasie the valve to the 25% of lift in most cases the valve is considered to be out of the head. Or the head will flow the same as if the valve was removed from the head minus stem diameter. This is always a goal in any engine from an engine with 3000rpm tq peak up to 7000 rpm peak. You will get your best performance from the engine with proper lift ratio. Now with small chevy it is not always needed because the engine make the same power with a few more points of duration but in big block it plays a larger effect.
whats the differences between 49 and 781 to other heads?? like 148. i have a set of 049 and 148. the 148 are 396 heads with a 110cc ported and fitted with 2.19 valves. were my 049 heads are stock no porting and 2.08 valve.and a huge 119cc. i measured with a caliper the inside diameter of the intake runner and found the 148 to be bigger. without flowing them i wouldnt know which has better velocity, wich is what i care about. and i really dont see any difference in design.
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  #34 (permalink)  
Old 12-06-2012, 09:13 AM
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If you want velocity (which isn't always a good thing) then you may want to look into methods of fillin gyour ports with epoxy. Stock BBC ports (more so than SBC ports) can benefit from adding some material in the right places. Its very important to do it properly though and use the right material as you don't want it coming loose and going into your cylinder.
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  #35 (permalink)  
Old 12-11-2012, 07:21 PM
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do cast iron heads gain compression because of heat??? i was told to keep the compression 9:1 were aluminum i can go to 10:1 i understand the heat issue with iron vs aluminum. i just wanna know if the motor is 9:1 will i gain compression when the car reaches operating temp. or is it just that 10:1 will start to detonate because of 91 octane
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  #36 (permalink)  
Old 02-12-2013, 07:43 AM
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completed my build. went for a 496 stroker kit from scat (492 only bore .30) and used the same soild roller cam in question. i bought some brodix BB-2 305 R ports. i upgraded the tranny to a m21. its fantastic!!! i am going to play with the rear gearing. but deffinetly not sluggish!!
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  #37 (permalink)  
Old 02-12-2013, 03:43 PM
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When I read your title, my first thought was you can never have enough motor. After reading the post, I think what you have will be more than adequate. It may be grumpy and annoying at times but worth it. Link us to some video when you have it together.

Kevin
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  #38 (permalink)  
Old 02-12-2013, 04:02 PM
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I second the request for a video.we need more videos here.
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Old 02-14-2013, 08:04 AM
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oh vinnie weres the trust!!! hahaha but i will get you your video. im still workin out the details oil leaks, hood replacment, etc.
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  #40 (permalink)  
Old 02-14-2013, 08:11 AM
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I trust,I like videos though,good inspiration
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