bowtie44s said:Ok guys, here is my build plan. I'm going to start ordering parts, what can I expect, what do I need to look out for or change?
Mark IV big block 9.8 short deck.
Bored .060 for 4.310, stroked .375 for 4.375, 6.385 rods and a displacement of 511in³. Forged crank, forged -18cc dome pistons, and forged H beams. I believe the bottoms of the cylinders need a little bit of clearance and I plan to do that myself before I have it bored. It is an internally balanced kit, so I will need a 427 or 396 flywheel and damper.
The heads are aluminum 300cc oval port. 2.25 intake valves, 1.88 exhaust, 118cc combustion chambers and Performer rpm intake.
The cam is a Lunati 10110316 lift .515/.515 duration at .050 is 221°/230° and LSA of 112°.
I am going to zero deck the block and use a standard .040" gasket. If my calculations are correct, I should have 10.5:1 static compression ratio. I found a formula online a while back and I think that cam intake valve close at 70° ABDC. If that is correct, my dynamic compression should be right under 8:1. I plan to run 93 octane fuel and CAN NOT run race gas.
I know that is a lot of information to chew. I have researched and crunched numbers to the best of my ability and need someone smarter and with more experience to step in and verify everything. I appreciate any help or input I may get.
there are plenty of well tested BBC 454 -496 combos, that have been repeatedly duplicated, simply because they are well known to produce the desired results.
you don,t need to do more than decide the approximate budget limitations ,and your skill level if your doing the work yourself , and do some research into your options, there's books and links listed in this thread that will provide a great many options and buying several would be a very wise investment
you don,t need to do everything yourself , you just need to know what needs to be done, how it should be done, how to verify its being done correctly!
http://garage.grumpysperformance.com/index.php?threads/another-496bbc.5123/
INVESTING THE TIME AND EFFORT IN PURCHASING AND READING A FEW BOOKS WILL BE VERY COST EFFECTIVE
a couple days of reading and asking detailed questions can save you thousands of dollars, and months of work
why not call and get a consensus or average of the suggested cam specs from at least 5 of the cam companys.
your problem here is that at that compression ratio and with that displacement your really on borderline detonation even before you get a tank of crappy fuel,and it will also run out of breath long before 5500rpm.
a 511 stroker WILL BEHAVE a good deal differently than a 454 with an over bore (460) and WILL require a good deal more duration, and going to a tighter LSA will allow the engine to scavenge and breath better
with a bbc with 511 displacement the advertized or suggested power range listed in any catalog is WAY off from what youll actually see, that engine can use a good deal more cam duration.
yes I know it says 2200-5200 rpm but thats based on a 454 WITH LESS THAN 10.5:1 static compression. what ever you use please post the results
that sounds like it has the potential to be a really serious torque monster of an engine, But Id suggest you Do those calculations again,your leaving a good deal of that combos potential power un-tapped, the cam LCA is to wide at 112, and durations a bit too low at 221 @.050 lift for a 10.5:1 compression engine with that bore & stroke ratio to run as well as it potentially might on pump octane fuel
why not call and get a consensus or average of the suggested cam specs from
crane,1-866-388-5120
crower,1-619.661.6477
erson,1-800-641-7920
lunati 1-662-892-1500
isky 323.770.0930
clay smith 714-523-0530
mark iv blocks
mark v blocks
(keep in mind that ALL '91 and later Gen.V and Gen.VI big blocks come with 4-bolt main caps. The two-bolt big blocks are no longer in production
MANY BUT NOT ALL aftermarket head designs have been modified to work on both the early MARK IV 1965-90 and later MARK V & VI blocks 1991-later.)
BTW, , on BIG BLOCKS the oil pumps and oil filter adapters are different due to the block oil filter recess and rear seals being different
GEN 4 or MARK IV
GEN V and VI
coolant holes in factory heads match factory blocks of similar version, aftermarket heads usually tend to have a universal coolant passage design that will function on most blocks but you need to verify and use the correct head gaskets
THERES A TON OF GOOD RELATED INFO IN THESE LINKS
http://www.projectpontiac.com/ppsite15/ ... calculator
obviously youll need to verify ALL your valve train and piston to valve clearances when you degree the cam in
but that howards cams looks close to ideal using my soft ware
THESE LINKS SHOULD BE HELPFUL
http://garage.grumpysperformance.co...ber-of-people-that-don-t-use-resources.12125/
Here is several related threads and dozens of related sub-links that will prove very useful, yes it will require hours to read through them but you'll save weeks of work avoiding mistakes and save hundreds of hours doing the reading and asking any related questions well before you run into potential problems by doing so!
http://garage.grumpysperformance.co...-peanut-port-big-block-combo.2900/#post-57145
http://garage.grumpysperformance.com/index.php?threads/another-496bbc.5123/
http://garage.grumpysperformance.co...e-springs-and-setting-up-the-valve-train.181/
http://garage.grumpysperformance.co...g-and-installing-connecting-rods-pistons.247/
http://garage.grumpysperformance.com/index.php?threads/what-to-look-for-in-a-good-engine-combo.9930/
http://garage.grumpysperformance.com/index.php?threads/468-build.11794/
http://garage.grumpysperformance.com/index.php?threads/cheaper-454-chevy-build.4620/
http://garage.grumpysperformance.co...gine-to-match-the-cam-specs.11764/#post-55571
http://garage.grumpysperformance.com/index.php?threads/finding-a-machine-shop.321/
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