The compression was adequate. Piston top was an inefficient design with too many possible hot spots. The cam was all wrong. How could this thing need 38 degrees of timing to make 300 HP? Apparently Comp Cams was hoping to sell more junk cams to keep the SBB community slow. Shave the heads on that engine throw a 310 or Crower level 4 at it with a qjet and run mid to low 13s
Sounds like a combo of everything. You can't show people on TV that you can take an old engine and do some simple upgrades n get gobs of power. You must have a credit card with a 10k spending limit and a summit catalog to get gobs of power out of an engine.
Best part on that build was the heads done by mike Phillips. He said the later heads need to be ported different from small Chevy to work. Big valves . 240 cfm is a decent amount for a strong engine. I bet a Crower level 3 in that exact engine would have made upwards of 360 HP with loads of torque
It does not take that much money to do it right, and you won't get those parts out of the Summit catalog. You need the TA catalog. I was disappointed too as I thought it would produce at least as much as mine did. Mine is 20 years old you would have thought that someone here would at least match my power or go foreword with more. Now instead of porting our iron heads we are going to sit around and wait a few more years for the alum heads as this engine gets put further and further to the back burner. You guys that are really thinking of putting out a hot 350 need to get your butts to the Buick nationals at Norwalk this year. this northeast area is going to be combined with the BPG and it should be good. This is your best chance to show your muscle. I don't want to hear your excuses I am calling you out. Time to put up or shut up. Desktop dyno session is over, time to put the engine in the car and meet me at Norwalk for you official butt kicking, by ME. :blast:
Yes let's flood bpg/Buick race day at Norwalk with 350s I'm trying to get my car going. Let's see some more cars out than last year.
What do you guys think about this guys view on cam selection? Sorry about the advertisments...ou: http://tru-442.tripod.com/camselect.htm
Mike said himself to me on the phone that he had to work really hard to get those flow numbers from the late heads compared to the early heads that easily flowed that much or better with less work. There is no question that the early heads are superior to the late heads both ported and non ported. It was my fault that the late model heads were used on this engine because when Mike Jr from TA was consulting the builders he was un sure what year heads would be best. Mike asked me and I suggested the late heads as they are less prone to cracking. The good thing is we got conclusive info about the late heads being inferior, because we never had that data before this... This leads me to flow testing the 71,72, and 73 heads to find out which year they turned restrictive. Flow numbers aside there never has been a hi powered 350 that i have heard of using the 74-80 heads... We have seen 290 intake on 68-70 heads but 240 was the best we have heard of with the late heads....
you do realize I was talking how they think on those TV shows, you need a summit catalog and lost of cash to go fast.
Was thinking that last night when some boob in a big caddy thought it was fast, drop into 2nd and pulled away hard. When I finally let off it took a good min for the speedo to come off the 85max pin.
i would say 72-75 heads are ok, 76 and up would be the questionable ones. and they can be worked as Mike Phillips said to port differently.Not to port like a chevy head as that will ruin the numbers.He did say that that was after putting big valves in them. maybe they are ok in stock form for a engine built around those heads.
I have 75-77 heads, and I will try to port them myself, with Jefferson Bryant book instructions, what are the main differencies porting earlier vs later heads?
really something we should get mike to explain, i think the change in heads have occurred with the change from red engines to blue engines
I stand by my quote above, I have no reason to believe the static compression was over 9:1 and with that massive cam the dynamic compression must have been WAY below acceptable levels. As Guy pointed out before this cam was close to a TA 510 cam and that cam needs at least 10.5:1 or better.. If you guys read back into the thread you will see that Derek, Andy, etc all agree about the improvement opportunities of the engine so lets not argue... Another thing worth noting is that this 75 engine started out at about 175 HP, so the 305 HP should not be too disheartening! When hot rod magazine did the twin turbo test on a Buick 350 it was a similar deal... They took a junkyard 74 engine and it dyno tested at 175 hp at the crank, they dropped it into a wagon with a $1995 turbo kit as the only upgrade, and it made what worked out to 350 hp at 6 psi boost at the crank when subtracting drive train losses from the chassis dyno test... Were they big numbers no but huge gains over stock and huge potential with more boost or a better engine under the twins. And the wagon still gets 20 mpg which is better than the 14 it got before the turbo upgrade. Regarding the head flow there is more to making HP out of head porting than just CFM numbers... The bridgeport work to port match the heads may not help the hp as much as the cfm gain suggests. Mike P said to me that it was easy to get good flow with the early heads...Here is what Mike P said:
We do not know when the cutoff from early to late is yet. That is why I am paying to flow test heads from 71, 72, and 73 so that we know the cut-off. Currently we know the 68-70 are good and the 74-80 are not as good both before and after porting. Until i get my testing done there is no way to tell the potential of the 71, 72, and 73 heads.... So the safe bet is the 68-70 heads till my testing reveals the 71, 72, and 73 flow numbers. Less potential with the late heads... I do not suggest any porting other than smoothing unless you are flow testing the heads. It is too easy to kill low lift flow looking for high lift flow and even with a flow bench it takes a lot of practice to get good gains. Each port should be balanced to flow the same as the others and it is impossible to do without a flow bench... Port matching and smoothing is not risky, but removing a lot of material should be left to the people with flow benches... I would guess that a lot of home ported heads are worse than stock at everything but high lift flow numbers. There were changes in the head castings many times through the 68-80 years, so many that we have not yet determined the stock flow or potential if each casting number... There is a reason that Buick kept changing the castings and I think it was to add reliability to the engine, then at the end to meet emissions. Here are the facts: The 68-70 heads flow great and have been used in success on many high hp buick 350 engines including the procharged 350 for which i provided the 68 block, crank and heads. The 68-early 72 heads are more prone to cracking.... The mid 72 and later heads almost never crack due to the extra coolant passages added. The mid 70s heads are restrictive and lack potential both before and after porting compared to early heads. There just may be a head that is both good for performance and reliability and that may be the late 72 and 73 heads but until my testing is complete we will not know. Also keep in mind two things about the cracking early 350 heads.... 1. Many heads have slight cracks but never any issues or leaks after many many years. 2. Many 68-72 heads never crack.
Your on buddy, hahaha :bla: just another 6 months of winter to get thru here in Ohio! Im gonna give my 350 GS hell this spring, or at least try:TU:
I would love to see Mike Jrs 350 Skylark make some good passes at Norwalk now that he has the single plane intake on there!
I am with ya on that, just wanted to rib you a little. I use both Summit and Jegs. Jegs does put more Buick stuff in their cat than Summit does.
