Howdy! I want to install a blower on a stroked 302 that I am building, but need the boost to be 6 psi, 7 TOPS. Talked with Holley, they say theirs is 8/8.5 minimum. Is there a blower out there that will do less boost, or is there a way to lower the boost on a 177 blower? Thanks!
Spin the blower slower. You should be able to get a bigger pulley somewhere. But before you do that, go and do an introduction.
If you can't get a larger blower pulley, maybe you can compensate by getting an underdriven crank pulley for the motor? Not sure how you figure out what sizes you need...but that should be the way to go.
A 177 blower is for 351W motors not 302. The 302 uses a 144 and its about 7# out of the box but more with pulley change .The 302 should have no more than 8-1 pistons other wise the #5 cylinder can burn the ring land-been there done it.
I hope you girdled the bottom end and put a forged crank in it, quality rods and bolts, these are a very utilitarian engine but they do grenade. Why not put on a super charger instead? What kind of heads are you going to run?
Not trying to be a smart***, but why are you limiting yourself to 6-7 lbs max? 1-2 lbs shouldn't make much difference.That is, unless you are using cast or hyperpathetic (misspelling intended), in which case you should stay away from blowers or get some forged pistons anyway. I ran 15lbs on a late model 5.0 block (with stock internals!), and had no issues. Edit: whether roots, centrifugal, screw, Latham, etc...they are all "blowers", or superchargers. As long as you are staying below 500hp or so, you don't need anything fancy. Stock rods, ARP bolts and mains, and forged pistons.
Unless your engine is way over 9:1, the difference between that 8.5 and 7 psi is pretty nill. Why are you scared of that extra pound and a half? Why not use an ignition with boost timing retard and enjoy the boost? Why couldn't you put a 177 or even a 671 on a 302 Ray?
Why couldn't you put a 177 or even a 671 on a 302 Ray?[/QUOTE] To my knowledge there is no production manifold to install a 177 on a 302. There are manifolds for 471 and 671 and should be no problem but the 9:1 and blown on a SBF dont work to well due to the design of the runners. I reworked a couple of blower intakes for a stock 302 roller and never could get the flows exact and had lean out problems at 8# with the front cyl. Possibly a homade blower intake may make it possible to run the boost up with the 9:1 pistons but to me not worth the effort.
well i have a 174 weiand blower running on my 306 been running 7 lbs boost no prob on 94 fuel 30 degrees max timing at 3000..so far done a best of 11.7 at 117 mph in my little woody by the way static comp is 9.58 to 1
I have a vintage Dyers 4-71 on a old Offie intake...all forged 302 running 8.6:1 compression with a big lopey idle...Blower is underdriven with max of 7lbs on really hard pulls - I rarely hit 7. Most pulls/cruising is between 3-6 lbs. which is plenty for me on pump gas. I wanted a cruiser setup, but wanted people to hear me whinning a mile away. As for the type of blower you want, there are options. Most old screw types need custom intakes to fit the ignition system as the blower drive is on the same side. Pullies are getting harder to come by as well for SBF, especially 2 piece balancer pullies...if you find them, hold them. Newer style blowers are more applicable to most SBFs in my opinion, but there are options.
Agreed, It's amazing how many people can go through the steps of signing up but can't read the part that says READ THIS FIRST http://www.jalopyjournal.com/forum/showthread.php?t=44274
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