Chevy 400

[Kaper]

So I picked up a sbc 400 for really cheap. I broke it down to a short block. It has the stock pistons which I think are rated at -20cc? The cylinder walls look pretty good. It has World Product Sportsman II heads part number 1115/I037, 200 intake runners and 64cc. Full roller rockers 1.5. I would like to go Hyd Roller. It came with a single plane Team G intake manifold. I plan to get an Weiand Air Strike or Eddy Air-gap manifold. My vehicle is a 1978 Malibu, th350 with a 3000-3500 stall convertor. I'm not sure about the rear end gears yet. I know it's a stock 7.5, but it has a steep gear in it now. When I get extra cash I'll probably update to an 8.5 10 bolt with 3.42 gears. Anyone have experience with the Comp Cam XR282 hydraulic roller or the 280HR Magnum Hydraulic roller in a sbc 400? I don't have any plans to run it at the strip.

 

[88ss408]

I don't have the roller cam but I did use the XE 274 and XE 284 in 400sbc and the liked it.

 

[Kaper]

Thanks. So would you say your idle quality was pretty good in traffic?

 

[88ss408]

I have my idle set around 1000. Its great there. If I try 850-900 it will some times stall out.

 

[crotchss]

Here's a link to a video of a 383 I built for a buddy's rat rod, it uses a XR288HR cam. https://www.youtube.com/watch?v=cOBaUai8Kuk Totally streetable if you ask me. I also have videos of XE274 and XE284 hydraulic flat tappet cams in 406's in two of my other videos. BTW all of these will idle at 800 rpm all day in gear with no issues. XE274 carries 15" vac @ 1000 rpm, XE284 carries 12" vac @ 1000 rpm, XR288HR carries 13" vac @ 1000 rpm.

 

[Kaper]

Thanks for the link. That's a sweet looking M.C. by the way. I was also checking out this cam
Cam Kit Brand
Howards Cams
Manufacturer’s Part #
CL110255-10
Cam Style
Hydraulic Roller
RPM Range
2200 - 5800
Intake Valve Lift
0.510
Exhaust Valve Lift
0.530
Advertised Intake Duration
284
Advertised Exhaust Duration
288
Intake Duration @ .050
231
Exhaust Duration @ .050
235
Lobe Seperation(degrees)
110
Rough idle
Street/Strip performance
Great low to mid-range torque & power

 

[crotchss]

That cam will definitely be streetable in a 406, should make a lot of torque down low. Just a little side note to remember, when they list a RPM range for a cam they are usually basing it off of a 350 ci motor. So that being said it usually shifts the RPM band down a few hundred RPM. Which can be changed some by retarding the cam timing. Also it may be better to keep the RPMs down a bit if you are running the stock rods and pistons in a 400. The short 5.565" rod length doesn't really like a lot RPMs, the sharp rod angle can cause a lot of side loading.. A cheap upgrade would be to use a 5.7" rod with aftermarket pistons to match. JMHO

 

[Kaper]

Yes, I figured the cam mfg. were basing the cam characteristics off a 350. This combo will see a track one or twice a year. It's going to be my street cruiser/daily driver for Spring/Summer until I save up enough money to H-Beams/Forged Pistons, and a aftermarket 400 block for a turbo build. What made you decide to use a 700r4 vs GN/442 200 trans? I've thought about using a 4-speed for this build, but I'm not sure yet as I have to tweak a few things on my 66 Cutlass. Did you pick the Hurricane intake to match your convertor? Just asking out of curiosity. The 1995 and up 4L80E seem like a good way to go for forced induction or massive torque applications. I've heard the earlier 4 speeds take a lot of dough to hold up in those applications. Thanks.

 

[crotchss]

When I bought the car the previous owner had shelled out the 2004r and replaced it with a th350. I got a good deal on the Bowtie Overdrives Stage IV 700r4, so I went with it. Yes, I went with the Hurricane intake to better match the converter I have in it. Yes, I'm also saving for a Dart Little M block and 4L80E to handle a boosted engine that I'm gathering parts and money for.

 

[ssn696]

I had my 400 with 5.65 rods and forged pistons right up to the 6000 rev limiter in my MSD 6AL box (several times, manually shifting an automatic...) . Never scattered it and had 70,000 miles on the motor before I rebuilt it again. Of course, I had the rods and pistons weight-matched and the rotating assembly balanced....

Did you put the GW control arms in yet?