Hi, i have some questions about Weiand 142 with a 350.

Iam pretty sure i will buy one Weiand 142 "WND-6500-1" to my 350 -73 engine.
It haves original heads, but what cam should i use for it? i don't know what cam its in it now but its not original,
and will this Q-jet be enough for the task JET Streetmaster Q-jet Stage 2 Carb "JET-35002" ?

And one more question fuel pump will a mechanic be enough with a blower?

Thanks

 

If it's a 73 then chances are it's a low compression (8.5:1) engine- which is good, if you're running a blower. Detonation is quick death with boost- especially with stock cast pistons. Run it lean or get greedy with ignition timing and it'll grenade pretty quickly. You DON'T want high compression with these blowers on pump gas.

These little mini blowers don't like lots of RPMs. They get the job done with TORQUE and lots of it. Big cams are neither required or wanted. You'll get the job done by 5500 RPMs at the most, maybe a bit higher with good heads. I'm talking about a SMALL cam.... Somethign with about 210* intake duration, 10-12* more duration on the exhaust and a wide Lobe Separation Angle of 112-116*. The Comp NX (nitrous) cams actually make very good blower cams if you stay on the small end of the range. Like the Comp NX256H.

On the super-cheap, check out the Summit house-brand SUM-K1102 (or the slightly bigger SUM-K1103) cam and lifter package for only $80! It's made by Crane and is the same as the entry-level Edelbrock "Performer" cam. It's not the latest in lobe technology, but it'll work for cheap. I have the K1103 in my motor right now.

A good performance-built QJet should work fine- I use one on my 142-blown 383 in the Malibu! Mine's just home-built, is all.

Just make sure you have plenty of fuel supply. On my Malibu a mechanical-only pump wouldn't keep up under hard acceleration. I had to install a low-pressure "helper" electric pump back by the tank.

 

My 355 does fine with a 142 on 8.8 compression and boost. I have a 750 Proform Mechanical seondaries race carb with no choke and holley 170GPH mech pump. I have a summit K1005 cam and 1.5 full roller rockers. Cam is very mellow and a 3k rpms stall it is a blast to drive. 5psi it ran 12.42@109.8mph in a full trim 69 chevelle.

The blower really doens't need more than 230 druation @.050 cams or .500" lift. I put on a smaller pulley and ran 110 gas through it and it ran killer! Well,it still runs but it won't run on pump gas with more than 6-7psi and my compression. Money well spent is a wide band 02 gauge to monitor air fuel ratios during WOT blasts. You must not be lean on a boosted motor! A/F ratio at W0T should be 12.2 or 12.0 for safty sake. I think 11.9@114mph is doable with aluminum heads and lower compression.