well took my 72 lark to the track build as follows, calculated 8:77:1 compression 462 short block 284-88h ta performance cam holley 850 dp 70 small valve heads, minor bowl work b4b intake ta full length headers 3k b&m converter rebuilt 350 trans no shift kit TIME SLIP as follows i1-2.048 i2-5.598 i3-8.622@80.497 1/4-13.772@88.591 made 3 more passes around the same loaded up and came home, got it off the trailer this morning pulled into shop was running pretty bad. only holding about 30 lbs cold oil pressure and had a slight knock, changed oil and found some gold flakes in the oil so shes coming out of the car for a rebuild heres the deal: this car will stay all buick BUT i also have a 69 skylark as a drag car in progress, was planning to build a 455 for it as well considering i have 4 engines on hand. but with the build i had i was expecting mid 12s-low 13s with that being said my 2 thoughts right now are what is it going to take to get the 72 to run mid 12s AND hold up for years to come. ALSO what to do with the 69 to start out running mid 11s and hold together for a full season and refresh in the winter. will it be cost effective and as reliable in comparision to (bad as i hate to say it 454) ???????????
Same thing as facebook. it's a low compression, small cam motor with stockish heads. that's about as good as you will do until you put more money into it..
For it to only pick up 8mph on the backhalf you have a fuel issue, your current combo will go bottom 13's with no problem if it doesn't spin and pulls clean all the way For 12's in that combo, you will need more comp and more lift to help those small valve heads For 11's it depends on the weight and gearing say you weigh 3600lb with a 4.10 gear and will be running 110 rave fuel, I would say the easiest most cost effective would be the following SP1 intake Stage 2 heads, go ahead and spend the money now , don't waste your time with iron heads on a race car Minimum 11to1 comp, more is better Minimum 250 duration stick with minimum 550 lift 950 carb 4k+ converter If it's put together correctly it will run forever and run bottom 11's first time out The reliability factor has absolutely nothing to do with it being a Buick or Chevy that falls back on the builder/assembler
well next engine will get a better pump and better valve springs, curious to figure out what hurt the engine so it doesnt happen again
motor was built and installed last thanksgiving, ran fine till the track, before the final pass we monkeyed with the timing and fuel. ran a 14.4 afterwards and wouldnt restart until timing and fuel was reset, possible lean detonation hurt it in a single pass?
Which pump are you referring too? Fuel pump or oil pump? I think you're referring to the fuel pump and I think hugger thinks you're referring to the oil pump it would seem.
Do you have an air fuel gauge to aide in tuning? If not you may want to consider investing in one. 8 mph from the 1/8 to the 1/4 should be closer to 20 mph more, so you quite possibly are running out of fuel on the second half of track? This could be from the jetting of the carb if in you're running way lean @ WOT? Do you have any air fuel data for your engine? And like hugger said, either engine can be built to be durable and I say that either engine can be killed pretty fast with a bad tune.
car does have an afr gauge, on the street it ran 11, 11.5 afr at wot depending on the weather, But when we adjusted it at the track i was paying more attention to rpm and not watching the gauge so couldnt say what it was at on the track
To do a cost analysis between the 454 and 455 you have to know more about the 454 and what you are starting with. 454 iron heads 'can' be ported for an 800hp build, and as you know...the parts get more expensive for each build scenario or level. You'll have to itemize each component and see how it stacks up. There's going to be power levels in which the two choices trade positions for cost. Even comparing the similar architecture and choices available, the Buick has a better combustion chamber and ports for a below 6500 rpm range. You'll potentially get more from the Buick below that. Long rods are available inexpensively for the 454, helping higher rpm ranges, but the chamber needs more timing. Ported Vortec BBC heads would even things up in the same range. If you were starting with large rectangle port heads, well over 800 hp is within reach, so what you save in head castings you spend back with a steel stroker crank and everything else.
What rear gear are you running? 60 ft looks like you could trim a lot there. Also as said 1/8 to 1/4 mph gain was minimal. I'd look in both those spots and I think you'd be low 13s maybe even scratch a 12? Although also as said I wonder how fast you can go with the 284 and 8.7:1. Peaked my interest though, I have a very similar combo with a 430...
BBC cores around my area are $1k so the initial cost is WAY more, my mention of the oil system is due in part to you wanting to know "how to make it live" for such a mild setup the stock oil system is more than adequate, loading a car at the track is COMPLETELY different than riding around on the street and getting on it , track runs will expose all kinds of issues not seen on the street. How you could detonate a 8.7 to 1 engine to the point of beating a bearing out if it idk, maybe if you had 45° or more of timing and 87octane maybe. Leaning it out could have melted a piston, but I doubt it, it just seen more load than it could handle for longer than it wanted too, ie problem was there from the start more than likely It takes a certain amount of HP to run a given 60ft with a given weight so don't go chasing Unicorns there with such a mild build 1.70's will be all you gonna see without a stupid steep gear and converter Some builders run the more common Chevy clearances which contrary to what some believe will work if you run the oil too acomadate it. My last 464 was pretty wide on the rods this was done intentionally by my builder he said run 20/50 which I did , and I ran the piss out of it, with stock rods and it saw 6500 to 7k rpm Everytime I drove it and even seen the other side of 8k twice on accident. I know a few other racers that run bigger than normally accepted clearances with excellent results, but anyway it may have been a fluke think anything can happen stock Buick engines blew up back in the day and so did many BBC's There are droves of used BBC performance parts to be had on hundreds of forums and whatnot, we have a used set of heads come available once a year where as Racingjunk probably has 20 pair at any given time, so that is a plus but lb for lb , mid for mod, Buick wins , I've outran so many ZZ502's it's depressing with stock Buick junk. Just do careful teardown to address what happened and buy some forged pistons with another point of compression dialed in along with a better suited cam for the driver car. Then if you truly want to get good numbers out of the "race car" use race components and high compression, don't saddle it with "street" stuff and expect good numbers, that hardly ever works and when it does it cost lots more money. I've been down that road more than once
After watching your vids on Facebook it seems like you are also having traction issues on launch. Either poor track prep or the tires went hot enough. I think you did say you were running DR's
There is a world of difference between what you do on the street and the track. Holding an engine at WOT through all 3 gears for an entire pass means everything has to be right. The track will reveal your weak spot every time. As soon as you saw you only picked up 8 mph in the second half, you should have known something was wrong. 20 mph is what you should have expected. Leaning a motor out at WOT is begging for it to detonate, especially with pump gas. A little race gas added in at the track is cheap insurance. That is how you hurt it. Live and learn. You will hurt any engine like that. If you want to build a stout BBB, start with good heads. They are the foundation for everything you do afterwards. You aren’t running 12’s without them unless the car is very light.
that's why i have a fuel pressure gauge. leaning out at the top end of the track at 6k is very dangerous. I made sure the fuel pressure was steady with a second set of eyes on the old Chester A Arthur national dragway before I went to to track.
12s shouldn't be a problem even with stock heads, I had a 67 Gransport in the 12s with the 400 it came with, factory Stg2 cam 11.1 pistons and a 360 Edelbrock 400 S/P Turbo with 3.90 rear gears. As mentioned you were probably starving for fuel and damaged your engine. As far as a BBC goes I sold my bracket car 64 Skylark minus the engine and trans. The new owner went with a BBC and slowed the car a full second. Bob H.
Be careful with statements such as these, or you'll end up with 5 extra thread pages trying to defend this position. lol I am, of course, in agreement.
