318 Blower build, looking for opinions.

[SniperDel]

Hey everybody. I'm looking at doing my first roots style blower on my 318. I know 318's need head studs, triple layer gaskets and they'll do ok for the most part on 12lbs of boost. I'm having the hardest time finding an intake manifold for a small block mopar application. I want to slap on a small weiand blower (makes sense, you'd think they make adapters for them) but I've turned up a blank. Have y'all four anything else like the old B&M setups? Thanks.

 

[dieseldazzle]

Call dyers, get them on the phone and tell them what you are looking for. They have all kinds of stuff, very helpful folks.

 

[dvw]

I've run a roots blown 340 since 1985. My manifold is a modified Offenhauser from Dyers. Studs and Felpro's at 12 psi will live if you don't detonate it. If you do and your lucky you'll blow the gasket. If your not lucky you'll take the ring lands out. Do not run much more than 28-30 degrees total under boost. That being said my sons turbo 360 with about the same mods at the same boost is at least .5 second faster.
Doug

 

[SniperDel]

Yea at this point I've never done a roots blower on a carb'd engine before. I've been fuel injected until now. I'm excite but I'm also looking to learn. Figured a 318 because they're cheap if I do mess up. Any suggestions?

 

[dvw]

What are your goals?
Doug

 

[SniperDel]

Realistically, about 450-500 horses crank. I've been reading up on guys doing that on 10-15 lbs of boost with stock long blocks running 11's. I think it's very feasible, especially with 4.10 gears.

 

[dvw]

What heads? 500hp is doable with a turbo at that boost on a stocker but I'm not so sure with a roots.
Doug

 

[SniperDel]

They're stock heads (need to get the numbers). I'm going to get them worked on. Cleaned up, rolled rockers, etc. also gonna do arp studs. I found a weiand 177 for 1400$ new from a speed shop. The guys were gonna put it on a 408 sbc build but figured out it wasn't going to produce enough boost. I got the blower coming in tomorrow minus the belt, crank pulley and manifold. I was going to do a manifold adapter plate. I still might but it'd have to be either higher or I need to change my radiator out so the coolant hose doesn't interfere. Here's all I'm figuring that I will need.

650-750 carb (350$)
2-4" aluminum plate (intake manifold adapter, just gotta find it)
larger fuel line?
crank pulley + adapter (120$)
ARP Stud kit (150$)
belt (30$)
hei distributor (60-200$? Still not sure which make I should get)
2800 cfm electric fan with relay cut off kit (found one for 60$)
MSD boost timing control module (found for 140$)
Head/manifold gasket set (100$)

As far as I can figure doing a stock long block that's the basics that I will need for now. I personally want to get the transmission redone and I have a Mopar 8 3/4 with 4.10 posi's that I need to get bearings for and rebuild. Probably also need new studs for the axles as well. Any input is greatly appreciated.

 

[dvw]

A stock 318 will struggle to meet your expectations. Cam is way to small, blower is small, carb is small. Back when I started it had a 340, bowl ported heads, 1 5/8" headers 3.91, crane 467/.497@114 lca, 8-1, open headers. It ran 11.80@113 @3875lbs. Changes; better ported 308 factory heads, [email protected]"/.540" cam on 110LCA, 4.30, 2" headers, good 9" converter. Now runs 11.0@122 through the mufflers
Doug

 

[SniperDel]

I thought you just said 500 was doable on a stocker is doable. Correct if I'm wrong but isn't boost still boost by any other name?

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I am curious with how you did the water pump pulley though. Not sure if I'll have the clearance or not. I should.

 

[dvw]

I thought you just said 500 was doable on a stocker is doable. Correct if I'm wrong but isn't boost still boost by any other name?

- - - Updated - - -

I am curious with how you did the water pump pulley though. Not sure if I'll have the clearance or not. I should.

Originally I ran the stock alt, water pump pulleys. We made these aluminum parts later. Boost is not boost. Roots is not a compressor, just a pump. Boost made by a roots is due to intake restriction and heat. They are pretty inefficient. My sons turbo car and mine weigh about the same. When we first put his together it was a near stock 360. Forged pistons and a reground factory hyd roller to .500" lift and bowl ported stock heads. 255/60 drag radials and a 2.76 gear. Running E85, no intercooler 750 blow thru carb it went 10.50@127. Mine has a 5300 converter, ported factory heads, .550" solid, 2 carbs. 11.0@123. We have since added Eddy ported heads and a .550" lift cam. 3.55 gear, 275/60 radials, cal tracks and good shocks. At 18 psi his has been [email protected] Currently we are turboing a stock 318. Installing the reground cam and springs from the 360. The rest will be stock (single plane swap meet intake and a blow thru carb). It's going in an A-Body we'll see in the spring how it runs.
Doug