the planed BBC combo

[grumpyvette]

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/

 

[philly]

david vizard posed an interesting question... call a cam company gives them specs and get a cam recommendation, then wait a couple days and have you buddy call and do the same for the same motor, then wait two weeks and have someone else call again for the same motor and see how many different looking cams you get.

 

[grumpyvette]

thats VERY TRUE, (you seldom seem to get the same recommendation twice, under the listed conditions mentioned above) and one reason why Ive strongly suggested you call a minimum of five to seven cam manufacturers, tech departments, giving them the application specs but...never discuss what others might have suggested and average the results then buy something similar to that AVERAGE in LCA duration and lift, as that method tends to eliminate or at list strongly reduce any really off the wall suggestions from screwing up the choice

http://garage.grumpysperformance.com/index.php?threads/another-496bbc.5123/

http://garage.grumpysperformance.com/index.php?threads/oval-port-afr-head-565-bbc.11076/

http://garage.grumpysperformance.com/index.php?threads/cheaper-454-chevy-build.4620/

http://garage.grumpysperformance.com/index.php?threads/540bbc-335cc-afr-head-combo.10627/

http://garage.grumpysperformance.co...ting-big-block-chevy-454-cam-dyno-test.10181/

http://garage.grumpysperformance.com/index.php?threads/basic-lower-cost-big-block-build.10502/

http://garage.grumpysperformance.com/index.php?threads/489-bbc.8383/

http://garage.grumpysperformance.co...rt-a-non-issue-based-on-mis-information.6414/

 

[87vette81big]

If it does not say Drag Race only I am not interested in that camshaft.
Radical enough so it can't be used with EFI .

 

[Grumpy]

I have been talking with David at Lunati, I told him I'd prefer to go with a hydraulic roller for the obvious reasons. He recommend I get a custom grind. He said 227/231@.050, .600/.607, 110LSA with 106 intake centerline. He assures me it will run fine on pump gas with my 10.5:1 static ratio and it will start pulling hard at 1500rpm.

What do you guys think?

sounds like a cam far closer too ideal in that application!

 

[grumpyvette]

Thanks grumpy. That was my thoughts. He said I "shouldn't" have to worry about piston/valve clearance, but I needed to check. The only way I know to do that is get the cam and see. I'm not aware of a way to tell when the valve is at full lift from cam specs.

Hopefully my last question. The can with 227/233 and 110 has the intake closed at 60° ABDC. That will put my dynamic compression at 8.62:1. Do I need to start worrying about pump gas?


I just got an opinion from Howards. He said b120325-10
229/235 589/600 and 110.

Evidently none of them are worried about interference with lift in the .600 range.

Grumpy, you told me early on. I got verification from about 5 people that you were right.You've been a huge help, I'll be sure to post a thread when I get it done.

you do realize you can install the cam retarded 4 degrees (SPLIT OVER LAP) and further reduce the potential for detonation with cheap low octane fuel which will move the whole torque curve an additional 150-200rpm higher , both to your benefit DON.T YOU?
and yes that's how I'D INSTALL IT
AND HOW I INSTALL MOST CAMS


http://garage.grumpysperformance.co...-get-it-to-last-cam-install-info.90/#post-497

http://garage.grumpysperformance.co...king-piston-to-valve-clearances.399/#post-488

http://garage.grumpysperformance.com/index.php?threads/cam-degree-equipment-tools.1759/#post-4440

http://garage.grumpysperformance.com/index.php?threads/degreeing-in-a-cam-correctly.3097/#post-8240

 

[Grumpy]

I did not realize retarding the cam would make it less prone to detonation, but I did realize it would move the power band up, which I was hoping to avoid.

I finally finished the job that had me on the clock longer than the cam companies were open, so I called some.

Isky recommended 549/552 219/228 a .050 and 112 separation. They would have to make it.

Crane reccommends 13HR00209.
236/244 610/632 and 110. That seems like too much lift to me.

Crower recommended 01403.
229/237 563/586 and 110. I believe that is the one I'm going to go with.

Well, the part I'm worried about with the high lift is the piston/valve clearance. I really have no idea how much clearance I'll have. Sure, I could put an indicator on the valve and see how far it will open before it hits at TDC, but I realize the intake valve isn't at full lift until it's on its way down. Is there a way to tell where full lift occurs from the cam card? I'd think the exhaust valve would be the one I have to worry about, but I could be wrong.

I just got an opinion from Howards. He saidb120325-10
229/235 589/600 and 110.

Evidently none of them are worried about interference with lift in the .600 range.

Grumpy, you told me early on. I got verification from about 5 people that you were right. "

retarding the cam a few degrees delays the valve fully seating in relation to the piston moving upwards while its compressing the cylinder volume.
your problem IS NOT GOING TO BE A LACK OF LOW AND MID RANGE TORQUE,its likely to be detonation, even the CRANE cam with 236 duration if far from "over camming it" in fact its a decent choice.
keep in mind as you add duration you can add lift WITHOUT having an overly aggressive cam lobe ramp, as it allows a more gradual lift per degree of rotation.
what ever you use please post the results
CROWER has a similar cam
http://www.cnc-motorsports.com/crower-01404-hydraulic-roller-camshaft.html

http://garage.grumpysperformance.com/index.php?threads/dynamic-vs-static-compression.727/

http://garage.grumpysperformance.co...ow-to-reduce-its-likely-hood.9816/#post-49741

http://garage.grumpysperformance.com/index.php?threads/engine-compression-vs-knock.9252/#post-33366

Well, I finally have it done and have been running it a few months.

I went with a Howard's 120326-10. 229/235@ .050 .589/.601 and 110 lsa. I ended up with 10.43:1 static compression.

I am running a 180° thermostat and have the timing set at 14° with vacuum advance locked out to 10° for a total of 24° at idle. I could get some predetonation so I went from 44 to 42 plugs and that helped a lot. Every once in awhile, I can still get some. I may retard the cam 4° and see if that eliminates it.

It runs good and I'm super happy with it. Plenty of torque and still pulls hard to 6000 rpm.

 

[Loves302Chevy]

bowtie44 said: Well, I finally have it done and have been running it a few months.

I went with a Howard's 120326-10. 229/235@ .050 .589/.601 and 110 lsa. I ended up with 10.43:1 static compression.

I am running a 180° thermostat and have the timing set at 14° with vacuum advance locked out to 10° for a total of 24° at idle. I could get some predetonation so I went from 44 to 42 plugs and that helped a lot. Every once in awhile, I can still get some. I may retard the cam 4° and see if that eliminates it.

It runs good and I'm super happy with it. Plenty of torque and still pulls hard to 6000 rpm.

Any further updates? FWIW, I thought that Howards cam was the best choice also. But I did not calculate your DCR.