|06-25-2014 12:54 PM|
|vinniekq2||enjoy it for what it is for now,,,|
|06-25-2014 12:45 PM|
|naz4kez||sorry i havent been on here guys, there is an overwhelming amount of motorhead knowledge floating around here. And i have only scratched the surface of trying to learn it all. I really appreciate everyones input and due to not wanting to slack on the build this engine deserves i ended up breaking it down to the block cleaning everything up full gaskets accessories and clean and put it back together with intake and headers. I am currently saving up so when i do get my game plan together i can do it all right and the way it should be. so basically i just have a stock freshened 454 that breathes a little better. however once I get my funds together I will be getting full rotating assemble for a 9:1 CR with full hydraulic roller valve train, and these will be kits to ensure they mesh together, all parts will go to the machine shop here in Utah to get aligned and more than likely ill go .30 over bore. if i can afford the forged bottom end and convince my wife then maybe ill put baby on a bottle for track days. thanks again guys for putting the time in and bringing me to reality on the right direction for this build. they say money cant buy happiness, but it sure can buy horsepower which in turn equals happiness, so who ever thought of that analogy never owned a BBC|
|06-14-2014 01:02 AM|
|06-13-2014 05:46 PM|
|06-13-2014 05:32 PM|
|vinniekq2||Richard,did you say a "hydraulic roller cam"?|
|06-13-2014 04:34 PM|
Just a few thoughts.....
"-edelbrock performer RPM"
Good choice for a street motor, will make more power under curve than any other manifold idle to 6000. Sidetrack the Air Gap, use the standard Performer RPM #7161 for oval port heads. That Air Gap BS is just a way to snooker more money out of the unsuspecting hot rodder. Only way you might possibly need an Air Gap is if you only drove in the summer in Phoenix.
"Summit/flowtech brand LT Headers 3" collector"
Make sure the flanges are at least 3/8" thick. Thinner flanges will warp from the heat and will leak and spit out the gaskets.
"comp cams roller tip cast rockers 1.71 ratio"
Steaming piles of dog poo. Worthless in my view. The trunnions on these have been observed turning blue from the heat generated by the ball and socket arrangement, particularly with strong valve springs. The roller tip is next to worthless, it does not roll on the valve tip, it skids across it because the roller is too small in diameter to effect a mechanical couple with the valve tip. If Comp really wanted to build a good rocker arm, they would have built one with a roller trunnion and a conventional "walking shoe" tip.
"high volume oil pump"
Street motor does not need a high volume pump. All it will do is to add stress to the pump drive and the drive gear on the cam and the driven gear on the distributor. Use a standard pump.
"holley 770 street avenger carb"
Needs more carb.
"Here is the cam lifter kit I ordered but before install i want to make sure its the proper selection. i went small so i dont overdue the recommended lift on the stock springs.
You don't know the exact static compression ratio, so there is no way you can intelligently choose a camshaft. For the love of God, stop and ask questions first. If this motor is indeed stock SCR, then it needs a stock cam, one that will close the intake valve at the proper time to make reasonable cylinder pressure and still ward off detonation.
"upgrade springs, maybe comps 340lbs seat pressure with double spring, not sure which ones will get me the lift i want."
A Top Fuel motor might need 340 lbs on the seat, but anything else will need less pressure than that. I know you have mistaken seat pressure with open pressure. If you are planning a flat tappet cam (BIG MISTAKE IN A BBC, then the over-the-nose at 340 lbs would no doubt result in a few roached lobes pretty quickly. Big block Chevies just have a natural tendency to eat flat tappet cams. Use a hydraulic roller cam. Use a hydraulic roller cam. Use a hydraulic roller cam. Use a hydraulic roller cam. Howards sells cam and lifters for about 600 bucks. You'll spend more than that cleaning up the messes from fragged flat tappet casualties. Every time you frag a flat tappet cam, the entire motor needs to be disassembled and cleaned of the shrapnel from the cam and lifters that went south. A roller tappet cam does not need any special break-in procedures or special jumping through hoops during assembly. Just bolt it in, fill the pan with any off-the-shelf detergent oil and run it.
"could i mill the heads instead to bump CR?"
No. You need another point and a half (9.5) and you'd never get there cutting the heads.
Measure the stack of parts that you have or will have. For instance, compression height for a standard 454 piston is 1.640", connecting rod length center to center is 6.135" and the radius of the stroke is 2.000". Add these values together and find a stack dimension of 9.775". This will be the "stack' of parts that you will fit into the block. Now, since the blueprint "block deck height" dimension of a BBC is 9.800", this means that a standard stack of parts will leave a "piston deck height" of 0.025" (piston down in the bore with the piston at top dead center) of 0.025". (Any of the pistons will be down in the bore by a figure of twenty five thousandths of an inch with any piston at top dead center).
The factory used shim gaskets that would make a nice, tight squish which would deter detonation and effect good fuel mileage. Now, if the piston deck height is still 0.025" and you add a composition gasket, which is much thicker than a shim gasket, then you have destroyed the detonation resistance of the motor due to a much wider squish. Check the block decks and the heads for being flat within a couple of thousandths. If they are not, have your machine shop take a light cut to clean them up so the shim gaskets will work and the motor won't spit them out.
A far better plan: Check the main bearing bores for being round and parallel and correcting them with an align hone if they are not. Once the mains are round and parallel, chuck the block up on the mains and cut the block decks to the same dimension as your stack of parts, or if you want to keep a little more meat in the block, the stack dimension plus 0.010". That is called "zero-decking" the block and you'll be able to use a conventional composition gasket to set the squish. (0.040" gasket plus 0.010" piston deck height equals 0.050" squish, which is, in my opinion, just about right for a big block motor. Now that the block decks are equidistant from the centerline of the crank, the heads will bolt on squarely and the intake manifold will bolt onto the heads squarely and seal up properly.
Forget trying to do any gasket matching on a street motor. A study of fluid dynamics will tell you that the majority of flow is right down the middle of the port, so grinding on the sides or edges will only accomplish sore arms and wearing out of grinders. If you port match, the ports will end up looking like an Anaconda that swallowed a pig in side view. Where the ports are larger in the area where you port matched, the mixture slug will slow down because of the increased volume there and may drop fuel out of suspension because of the slowdown. Then on the next intake stroke, the cylinder gets a gulp of raw fuel. Leave the ports alone unless you have a PhD in Fluid Dynamics or have 30 years of experience as a professional head porter.
|06-13-2014 04:10 PM|
|vinniekq2||Cheap version, Bigger valves,850 HP Holley,deck the block and skim the heads,deal with w/e CR you get.Use true roller rockers on a BBC,good quality headers close to 2" primaries,long tube,,,a short duration hydraulic roller with .550 lift,,,, duration will depend on final CR,think around 210º or less if under 9:1 CR with 108º icl and 112-114º lda|
|06-13-2014 03:45 PM|
> 454 cam selection help!!
You got a good deal on a 454 engine. Now have you taken the engine apart yet? There is a lot of information you can get while the heads are off. You can use a straight edge and feeler gauges to measure the distance each piston is down in the bore. Write all this information down in a tablet. I had my 454 block milled to zero so I could use the most common head gaskets and to have my quench set at .040. You can measure the valves in the 781 heads you have. Look thru the springs and see what type valve seals are used. You will need to decide on your camshaft. You can look online at the cam and get the recommended springs. Its best to buy in a kit for a better price. I would call Howard's Cam or Isky cams for a recommendation for a cam kit. I have been reading these forums and Comp Cams has too many lobes on their hyd. lifter cams wiping. I would not use their cams unless it's a mech. roller. Check your pistons out do they have a dome or are they flattops. If they are flattops it would be cheaper to find a set of closed chamber heads 802,290,820,280 are some casting numbers. A 100 cc head with your deck milled to 0 will give you 9.2 compression ratio.
|06-13-2014 02:44 PM|
naz4kez....I wrote this post then deleted it a few times but here goes, I need to ask anyways......lets get back to some fundamentals/basics....Do you understand the difference between a SCR, a DCR, how it pertains to engines and the engines overall characteristics? Do you also understand why a proper quench /squish area is important to the overall? Do you understand the filling and emptying cycle of an cyl and why a camshaft is so important to the overall? Do you understand the importance of a strong valve train with proper geometry to the overall? (especially with a BBC?) Do you understand the need for a proper fuel curve and a proper ignition curve to the overall engine operation? The constraints of an application to the overall with a given octane requirement?
I think we all can get you there but we need to know where you are at in understanding engine operation and the why's.
Then you will understand why we are saying the things we are saying.
Not being condescending, just want to help.
|06-13-2014 02:16 PM|
|AutoGear||8:1 cr...I'd get a blower and have some fun. If it blows up, get another 454 and do it again. Yeah its redneck; but its a 3-ton truck|
|06-13-2014 01:56 PM|
|naz4kez||my bad autpogear, its going back in the truck lol. no dirt occasional track mostly street. im guessing the truck once i pull most the crap i dont want on it will weigh in around 5k|
|06-13-2014 01:29 PM|
This is kind of like apples and oranges but my 507" Cadillac build has 8.7:1 measured compression. It has lots of good stuff inside to make it reliable, mostly valve train components along with forged rods and ARP bolts everytwhere. It dyno'd 466 hp @ 5k and 535 trq. @ 4300. Now I was told by the dyno guys that if it was a true 10:1 engine it would probably be close to 500 hp and 600 trq.
It was built for the crappy gas we have to burn so thats why I kept the compression reasonable, it will still have PLENTY of power for what I want.
|06-13-2014 01:21 PM|
|naz4kez||street brawler, will never see dirt and will never tow. just want to eat up that kid at the light or roll smoke when i feel like it.|
|06-13-2014 12:19 PM|
You can certainly pull the heads off, check and make sure the deck is flat, and check the 4 corners to see if you need to have the deck cut; if you do, this may be a deal killer for you.
At this point you can also see how close to the top of the bore the piston comes up, and what kind of valve reliefs, domes or cups the pistons have...you may also get lucky and find a part number which would help immensely.
If the pistons aren't close to the deck; its going to be hard to get any efficiency out of this, no matter how much you mill the heads. You can play games with the head gasket, but if the deck isn't prepped properly you may have trouble with a shim gasket.
Once you know the state of your deck & pistons...now you can make an informed decision about milling the heads, larger valves to get the compression you like and the breathing you need for your performance goals. The camshaft should be the last piece of the puzzle.
BUT a towing rig, an off road truck, a street brawler or a daily cruiser...all have different requirements...start there
|06-13-2014 12:14 PM|
|naz4kez||shew 1600 for the rotating assembly, i know its probably a good deal but i forgot to mention im on a budget build... I KNOW the infamous BUDGET BUILD thing again lol. but i dont have the money to throw around for an all out build. so i guess i should have mentioned how do i squeeze as much power out of this thing for the ceap seats|
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