my 69 350 pontiac is in the machine shop and it is starting to get worked on now it has been boiled out and looks ok im trying to get 350 hp outta it any tips? there going to put in forged pistons srp i think pocket port the #47 heads with bigger valves roller cam and rockers and arp bolts thruout edelbrock intake and a 750 holley...they said they could rejet the carb cause its a little big? have i missed anything?
I would PM Q or Banshee, but only if your really serious about building it up. I have heard both of them talk about mean 350's in the past. They are to ones to talk to IMHO.
Skip the roller cam on a 350 and save yourself a ton of cash. Go with a K2801 (or K2802 cam if you have a manual trans) and a Quadrajet Carb. A 750 hooley is too big, even if it is rejetted. Jon (Carbking) knows way more about it than I do, and I apparently know more about it than the guy that gave you that advice. At least I think I do. And there for I am.
Use the E-Performer NOT the Performer RPM manifold.
ok they told me 1700 for a crate 350 pontiac...my motor i am providing most of the parts 47 heads, p4b edelbrock intake, compcams hydraulic roller 224 230 @50 502 int 510 exh k kit with 995 springs , full length headers, 750 holley dp . they are providing arp bolts , pistons , rockers , gaskets , pushrods , plus pocket porting the heads. i told them i want atleast 350 horsepower oh and largest valves they could put in 211 177 cause that was what was on the 350 ho... they are familiar with pontiacs but mostly 455's the told me 260 cfm would be pretty easy on a 4.00 bore plate and there most expensive radical port job was 300$ ohhh and they were going to balence the motor...the rods would be resized shot peened manafluxed n xrayed with arp bolts. they said stock rods are good enoough,, i have some howards aluminum rods but they said not to use em... the only upgrades i have requested is forged pistons (they want 2 use srp) and harland sharp roller rockers (1.65) comp said 1.65 was ok...so ontop of the 1700 it should not be much more i hope for those two upgrades...the only thing else is maybe have them port the heads more than just pocket port ? maybe have em do they 300$ port job.. they have a flow bench....it is k&m machine shop in raytown missouri and the guy doing the heads is kenvin flaridy...lots of guys have recomened him, they had 350 chevys..but kevin seems to know his pontiac stuff he suggested 48 16 62 heads but i told him that the 47 heads is similar just bigger chamber i thought and that the 350 ho had big valves and my block has the valve reliefs in the block...he said 750 olley to much and could be jeted down...but other wise 350 hp should be np....my car is a 4spd how much lose of hp can i expect in the car at the wheels? and should i tell em to put some more work into the heads rather than just a pocket port? they have a dyno but its like 500$ a day....i just want a car that wont get embarassed when a ricer pulls up or a mustang,,fast but not crazy,,i can always put a little shot of nitrous on it...i told them i might put a little shot on the car later down the road
I have a 69 350 4-speed with #47 heads that I had rebuilt as stock. I had a cam put in and changed it to a 4-barrel. That did not work for me. I bought a set of #48 heads that I had rebuilt. They had to fix the valve guides and finish a porting job some one had started. $1500 just for the heads and to install them. What a difference it made though! I have some #62 heads that I bought as back-up heads if you are interested in buying them. Pete
Not trying to bust on the self appointed wizard who taking your money, but he doesn't seem to undertstand the basic operation of carbs. Then again, a lot of guy who can sling around an impressive column of numbers don't understand basic engine operation.
The cfm and jetting are 2 differnt puppies. Cfm is the cubic feet of air per minute that can enter the venturie(s). The cfm of the carb and the engine must match. When you overcarb an engine, meaing using a carburator that has a higher cfm than the engine can use, it decreases the velocity in which the air/fuel mixture enteres the engine. The velocity "injects" the fuel in the engine, the stronger the velocity, the more power the engine has. I don't know where the point is where a 350 sucks enough air so that it can use over 650 cfm, but I don't think that the current configuration is in that area.
Jetting relates to air/fuel mixture. It's not that jetting doesn't have anything to do with cfm. Yes, cfm makes a difference on jetting. But you cannot reduce the cfm (in this case, the reduced cfm increases engine velocity) by reducing the jet size.
Something tells me that the guy has vested interest, such as more money in his pocketbood, by suggesting an oversized carb.
I know zip about holley's, but don't they make a 650 cfm holley? If you're bound and determined to use a holley, use the 650 cfm if such a puppy exists.
I'm building a similar engine right now. 350 with TRW forged pistons, 62 (if I remember right)heads. One thing you need to watch is your exhaust vavle clearance. Exhaust valves will hit the cylinder wall with around .475 lift. I should get my block back next week and that is one of the things I need to measure before ordering a cam.
Holly does make 650 spread bore carb. I've got one running on my Mopar 340 and it works very well.
-=>Lee<=- Due to budget constraints the "light at the end of the tunnel" has been turned off!
the 750 is free so i kinda wanted to use it....but maybe ill get a 600 edelbrock...and i had to yank my motor outta the shop...they bored it 60 over without calling...i told em 30 max and next thing i know there like it had some pitting and we had to go 60... i checked the bores they were clean except one that had a little cheese...it had so little wear the crank and mains checked fine... plus it started 1700$ then was 2500$ then like 2500 + or - 10%....and all the parts they were going to use were like speedpro and such...it took 275$ to get my engine back...so now i got it at another shop and its going to take 125$ to have the block final preped to assembly ready...that old shop didnt have anything in writing after 3 weeks....i didnt like we'll see how much it is when were done... is 60 over a big deal cause i heard 80 over is the max...
if you use too big a carburator , you`ll not be using all the gas , it will go right thru...= waste...plus it wont run as good as it will with the 'right' carb... just for comparison...I had a 50 Holley on a 302 in my fiberglass car, got 14 mpg...got a smaller Holley , got 19 mpg and car was quicker!
Talk to Jon of Carbking , my suggestion, and get the right carb., free or not ,that free carb will cost you more in the long run!
