So i have received a few private messages so if like to clear some things up I do not in any way ,shape,or form dislike or frown upon the 350 buicks Nor do i look down upon those who want to own ,modify,or have fun modifying them I actually think they have some benefits ,such as a nice long stroke to help make them more proficient at moving a heavy vehicle with minimal gearing and converter(good for street type stuff) A shallow valve angle which should help unshroud the valves (better coefficent of discharge at lifts )with a small bore And a sturdy block to help with ring seal which is paramount in any perf application The issue i have is the same old routine being performed with them resulting in the same outcome I have witnessed several mild 350 builds runnning mid 13s in Denver which would be mid 12s at sea level Yet these 350 builds i see on here seem to all perform the same with a few exceptions Heck,Underdog350 runs a pure stock 350 in the mid 13s that is basically stock I think attention to detail and some willingness to adopt some new ideas ,and step away from the same old song ,per say,will yield impressive dividends Instead of people complaining T/A or someone isnt making parts for the 350,why not spend time in the shop making what you have better The T/A intake has alot of potential in it,WITH SOME PORTING as well as doing some things differently with heads Take advantage of lighter ,thinner stem valves, along with smaller diameter retainers,diff spring packages,and optimized head porting Also ,most ring packs for sbb's are very thick resulting in hi drag=friction =hp loss By running some diff ring packs,or even lighter pistons you can see some pretty impressive gains,due to less ring friction,along with thinner rings sealing to bore better,and a byproduct is quicker accelaration from reduced rotating mass.Also the stock rods would be happier with less weight so its a win win for all Also the whole idea that these motors dont need as much attention paid to minimizing quench ,due to inherent chamber design is ludacris If anyone who has even the slightest experience building an engine to make power believes that,then they are doomed to failure I also think there are some strides to be made with aftermarket heads,but a well ported 250-260 cfm head on 350 inches will make 500 hp if used on the correct shortblock,so dont look at the heads as the restriction or deal breaker I actually regret sometimes selling my 350 parts ,but i have wanted a bb in my car since the day i bought it,and now that im getting older ,and more patient,i am trying to go with my 1st vision of how it should be ,so to speak. But at times i think it would have been less of a hassle to run the little guy in the old Apollo Who knows,maybe ill build on again With that said,i respect ANYONE WILLING TO SPEND THIER TIME,AND MONEY LOL,WHILE POURING THIER HEART AND SOUL INTO DOING PRODUCTIVE THINGS SUCH AS ENJOYING THE HOBBY AND LOVE OF HOT RODDING Good Night
Well said Nick.... Here is a serious question. Can you ever "over port" heads? (I don't mean damage- I mean flow#s). A Guru on this board once told me an internal combustion engine is nothing but an elaborate air pump. The more air, the more power and efficiency the pump can do. . . What say you?
over port heads will kill your low and mid range torque, it would be like having a big cam big carb with no gear or torque convetor, bog city
I wonder if that's why my car is such a dog. I just put my car back to gether and here is my combo: 70 350, TA Stage 1 intake, port matched heads, TA 212 cam, 2 1/2 in headers, bored .030 over, 10:1 compression pistons, petronix points eliminator, stock quadrajet, stock 2.93 non-posi rear, used trans with unknown stall specs. Sounds great at idle...but when I put it in gear it tries to stall and is a total dog when I go from a dig....not even close to breaking the tires loose (which are 255 60 15 btw). What do yo think the issue is? Stall?? Rear gears??
yes stall and gears are not helping, you have 2 1/2 collectors not primary tubes right? was the cam degree in, it could be retarded, whats your total ignition timing that would make a differents if its set back or coming in too slow.
Another internet myth,slash poor info If the cross section and throat size is the correct size for that application,IT IS HIGHLY UNLIKELY A HIGHER FLOWING HEAD WILL EVER SLOW DOWN A VEHICLE :TU: Correct air speed along with higher flow is always a win win situation that will ALWAYS make more power There is a reason why the factory built engines now a days have much higher flowing heads along with moderate cam specs, these produce driveable ,yet emssion friendly packages that still meet the demands of performance But again,i guess this doesnt apply to the Buick crowd o No: Again its myths like higher flowing heads hurt performance that are silly,and basically m..........,well,just WRONG But hey,there is a reason why some people engines run better ,and those are the few who adopt to change and leave behind failure
Yacster, you want as much air as you can get untill you get to a certain velocity drop or you start to get turbulent. Both of them or just one can do what gsgtx said. The right velocity, no turbulance and lots of air gets you:3gears:
You have a good conservative build. I just sounds like you didn't spend anytime on the details. Did you degree the cam? Did you recurve the distributor to match the cam? are you getting good fire? is your stock carb in good working order? what about the fuel pump? ... These are details. Take your time and go back through them slowly checking each one. Good Luck!
I wouldnt go so far as to say "not true". It is sorta true. If you only have the ported heads without everything else to go with them, the port job will kill power:Smarty: Ive seen this with my own two:eek2: Small valves/ports help the low-end, so if you dont have the cam/intake/gears to let the engine take advantage of the new top-end potential of a port job... All you did was hurt the low-endou: ---------- Post added at 11:27 AM ---------- Previous post was at 11:10 AM ---------- Take a good long read, then about 5 more of LARRY70GS's power-timing thread. Nothing in that combo should be causing the stalling-into-gear problem. I would have doubts about running the ''stock'' Q-jet on that combo. I would either send it to someone that really, REALLY, knows how to tune a Buick Q-jet with a full list of engine specs... Or, sell that paper-weight to someone else and buy a 700cfm Holley:TU:
yes your right in a race car, but even then you dont want your max flow at 650 lift when your cam has only 550 lift. the flow should rise quickly.if a head flows 250cfm max. the lower the lift at which the number is reached the better. if you reach max flow at 500 lift it will have a better power curve then at 600 lift. if the continues to increase above the lift your running you will have lower velocity and also lower power.you want max flow quickly reached.about the Buick crowd it looks to me the hard core buick race guys are doing well, its the street guys that are having a hard time having a driveable respectable fast street driver. maybe its get to do with the wrong combo and too big of cams and over sized head ports.
I think your getting two different things mixed up here If the port in questuion goes turbulent(sonic choke where the sir speed i nthe port is too fast and the air at the apex of the shortun can no longer adhere to the port walls and sheers off )then yes gong to too high a lift beyond the capabilty of port ,can at times cause you to lose power after peak and therefore can slow down a vehicles acceleration But on any engine,even a street car,if you ONCE AGAIN I CANNOT STRESS THISENOUGH,PROPERLY PORT THE HEAD,NOT JUST MAKE IT BIGGER,YOU CAN AND WILL SEE A GAIN IN POWER DUE TO EFFICENCY AND CYLINDER FILLING Just because somebody has a ported cylinder head,doesnt mean its going to require ohter things to make the car not slw down more often than not a prolerly portedset of heads,ran on a car with the car with stock induction and exh system,will mae little of no change in behavior or power output because you cant get the air to the back of the valve due to limitations in intake manifold,carb and cam Now when you put in that larger cam,which doesnt have to even be that large,the right manifold(which is an extension of the cylinder head by the way,incl the chamber is the extention the other way,exhaust system etc)the engine can now begin to show its true potential because you have eliminated the weak link per say in the induction system If you installed a set of haead on your car that were ported too large for the combo(rpm,displacemant),it will slow down regardless of what cam,int you are running
after reading your 2 last sentences we are then in agreement, like i said and now your saying HEADS PORTED TOO BIG WILL SLOW DOWN YOUR CAR.:beer lol
Uhhh---nooooooooooooooooo-i dont think so It is true you want good low and mid numbers to help with cylinder filling-again this all depends on what you are trying to acheive And you took what i said out of content,totally disreagrding the other 80% of what i wrote INCORRECTLY PORTED,WRONGLY SIZED HEADS ARE WRONG PERIOD BUT ILL PUT MONEY UP TO SAY,A STOCK 350 WITH A SET OF CORRECTLY PORTED,HIGHER FLOWING HEADS,WILL ALWAYS MAKE MORE POWER THAN A STOCK SET ON ANY GIVEN APPLICATION But ,ask any good porter ,who has results, if you EVER WANT A HEAD TO STOP GAINING CFM WITH VALVE LIFT,then get back to me If the answer is the same as you believe,run away from that guy Just because you reach a target cfm your happy with for a given app/lift,doesnt mean the head flow will/should fall like a rock afterwards if you were to open the valve farther if it does,i promise you it will be slower and down on power compared to a head that does not stall but hey,im not here to sell anyone a bill of goods,my stuff runs just fine :laugh:
I think youre forgetting the original question. He didnt ask if ported heads lose power. He asked if you can ''over'' port heads and lose power. And the answer to that question is yes. I know that for a track tested fact:Smarty:
Whats the difference bewteen over porting and incorrectly ported for the application ? I belive the nomencalture should be correctly or incorrectly ported for the application,not just too big or too small! Thats like saying your not short,your vertically challenged p
Exactly:bla: Thats why Im puzzled by your arguments. Your not wrong, your just not getting the original question. I had a customer do the exact thing the question asked. He had me do a monster port-job on a Pontiac 350 then, against my advice, stuck them on the engine without any other upgrades... Turd would be too kind of a descriptionou: It went from spinning the tires at idle till it crapped out at 4200...To sluggish and weak till 3000, pulling OK to 5000 then running out of breath:shock: We then installed a bigger cam, headers, S/P intake, 2500 stall-con, 373s, shift-kit, re-curved HEI and a 750cfm 4160 Holley... Then it came alive and launched hard off the line and pulled hard till 6500:3gears: In the 1/8m it went high 11s stock, low 13s with just a port-job, and low 8s after everything was working together. This wasnt a race-car BTW just a weekend warrior '79 G/P street-car with a '72 engine.
Yes this is true,although with a 350 Buick head I think the max anyone got out of them is just under 300 CFM,and this is NOT enough to slow down 350 CID.(example of good flowing heads with a restriction and still making a ton of power would be when a NASCAR car that has to run a restrictor plate,it slows them down,but the power is still higher than with a lesser flowing head) Now if your talking about a 429 Cobra-Jet head,this head was designed to run in NASCAR,and the power output is all in the upper RPM range,and on the street they were dogs out of the hole. Now,if you take those same heads and put them on a Ford 514 stroker(or larger) with the extra bore and stroke size the air volume is more efficiantly utilized,and low end torque is restored. Another Ford example is the old 351 Cleveland heads that the ports would fit a tennis ball though them,these heads had no velocity for low end,and were horrible out of the hole. But again,if stroked to a 408 would be much better. I would like to know WHO has ported their 350 Buick heads over 300 CFM,I want them to port mine!!! LOL Another example of a good running good gas mileage and excellent low end torque engine is a LS1 that has the factory L-92 rectangle port cylinder heads that flow over over 300 CFM from the factory(I think around 320). Granted most of the old Buicks aren't using the newer technology on their engines,like coil on plug,lighter rotating assemblies,thinner rings,roller cams with modern profiles designed to utilize that kind of flow,and of coarse fuel injection that doesn't have to rely on a vacuum signal to idle,and I almost forgot to metion,GEARING,which is VERY important with the mordern engines. If all the new technology is installed on an old Buick 350,it would run as good as an LS series engine,or bettter depending on how its built. This doesn't happen with the Buick crowd because,lets face facts,most of the people that own an old Buick bought one because it was half the price,or less than one of the more popular muscle cars out there,and every 350 build I've seen on here is on an ultra low budget. Hows that old adage go, how fast do you want to go? How much $$ do you have to spend. And another point is that most amature engine builders on a "budget" just don't have the skills do a modern build on a "budget" without cheaply sourced after market parts available for other engines. If that budget could be increased by maybe 50%,lighter,stronger after market rods and more modern pistons could be used,that I have posted in other threads,that would help the endurance and performance signifigantly. And a step futher would be a roller cam and lifters that are available at a price,that would only add to the builds performance. Instead of whining about the Buick 350,people should get off their wallet,and build one right the first time! So in conclusion, a Buick 350 head CAN'T be ported to much,if it is,the porter would hit water! Who ever is running good ported heads on their engine and it runs like crap,then the person that tuned it doesn'r know what they are doing and should seek professional help.
I would like to see what a stock 350 buick would run like with 280 to 300 cfm heads. Be kinda neat to start adding a cam , stall, gears ect. one at a time. I have read on some of the aftermarket heads websites for sbc that they do claim when they start getting about 220 and 230 cc and 310 to 330 cfm they arent recommended for street. They are a race head. But we all know poeple are useing them on the street. Had to use the sbc for example because we know the sbb only has factory heads to choose from.
