400 build

[gwcrim]

Plan is to get a 400 short block from my neighbor this weekend.  He bought it in kit form from a machine shop a few years ago and dropped it in a street rod.  He thought he heard a knock so at maybe 150 miles, he pulled it out and stuck a 350 in it.  It made the same noise.  He thinks it is a noisy top end as he used the same Brodix heads on both. 

For a paltry sum, I'm supposed to get the short block this weekend.  It's got 0.030 flat tops, stock short rods, and a new aftermarket balancer.  Probably an oil pan and whatever else I can get him to toss in.  His house is like the Summit Store.

Here's the idea as of now.  Start with Air Flow Research 195 Eliminator heads with 75cc chambers.  A bit pricey, but excellent heads and they should keep the compression around 10:1.  Heads are where the power is made, these fit my build perfectly, so I'll bite the bullet on the cost.

Already scored a Performer Intake and new 600 Edelbrock from the neighbor last year.  Carb size is marginal.  I have an old 3310 Holley as a back up.  I've given a whole lot of thought to FI but the low cost retrofits really limit cam selection and the entry fee to the tunable name brands is over two grand.  Hot Rod Mag's, David Freiburger tuned a 3310 to run almost as well as a Holley FI system.  Since my carbs are on the shelf paid for and jetting costs less than a night on the town.......  I'll probably stick with a carb.

I talked to Affordable Fuel Injection about their set up.  Price is right and seems straight forward.  In order for it to work well at low speed they advise cams of well under 220 degrees at 0.050 lift.  I think that's a bit tight for my goal to run pump swill as fuel.  Won't to much for my goal of power pulling over 5000 either.  So I found this cam....

Comp Cams Dual Energy 12-209-2. http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=105&sb=2 Pulls from two grand to six.  Stock converter, streetable, and enough lift for 1.5 rockers.  The heads will support 1.6 rockers but it sure will be a lot of lift.  .492/.514  might be ok.  Otherwise it seems like a perfect fit. (Alleged lopey idle too.)

Most likely top it off with M/T valve covers in wrinkle black and maybe even a snorkel intake out to the grill.  Yes I'll get a new radiator too.  Can't have the 400 live up to it's bad reputation.  I'm trying to restrain myself and build it for streetable torque, not top end.  Looks like a good shot to me.

So.  400 lbs of torque?  By God, I hope so.  400 HP? 

[Stewart G Griffin]

If i ever get around to it, Dart, Gm and another(?) sell NEW 400 blocks.  i want to go that route if i try to build a 400.  They cost over $2000, but it might be cheaper in the long run than taking chances with used, stock 400 blocks.

It's great that Frieby got that much power out of a 3310.  Too bad he NEVER explains anything in any detail.......

Same here----the only thing keeping me from fuel injection is cost-----the cheapest FI system i've seen is $1300.  i need a new mechanical pump which is about $30 and i already have a carb.  If i need a new carb then it's about $300-$450.    So that's why i'm sticking with carbs.

[gwcrim]

They used an A/F meter and it probably took them a day or two to get the jetting on.  Fuel mileage was on average of only 1 MPG less with the carb and it actually started quicker.  Edelbrock has a very good manual for jetting and all they recommend you use is a vacuum gauge.  My 3310 is probably 40 years old and has been on more engines than I can recall.  My pals like to bad mouth it because it's a vacuum secondary carb but they all liked to use it when they were diagnosing other carb problems.

This truck probably won't see more than a couple thousand miles a year (at least for now) so it would take a long time to justify the cost.  I'd rather put the cash toward a 700R4.  The 3.73 posi is steeper than I had expected with the short tires I'm using now.

I'm getting pretty stoked.  Haven't built an engine in years and years.

[Engineer]

Cubes are good for building torque. Good starting point.

Don't forget to drill the steam holes in the heads before bolting them on the 400 block. I ran a 400 and never had overheating issues. But then again my 400 had the GM heads on it.

And if you have time polishing the combustion chambers, and eliminating sharp edges will help with overheating. Just be careful to only polish, and not remove more metal than what this requires or you will lose compression.

If the 400sb doesn't get it done for you building a BB 427 with 049, or 781 GM heads certainly will. I went from a 400sb to a BB 396 and couldn't believe the difference.

[gwcrim]

I'm normally a big block guy but pick ups are front end heavy by nature.  With the aluminum heads, intake,  and no doubt a water pump, one part of the strategy is to make the most power with minimal weight.

The chambers and ports are CNN machined.  Hope they don't need attention but if so I'll clean them up.   There's bound to be videos on YouTube showing how to drill the heads.  I'll be looking at them.

Tomorrow's the day.

[gwcrim]

Here it sits.  A little bit of surface rust on the cylinder walls and in need of a cleaning.  No extra parts but the damper is new as is the flywheel and notice the chrome pan!  Ohhh... shiny!

Need to check deck height and make final decisions on the top end.

[gwcrim]

I measured the deck height at 0.045-0.055 or so.  Add in 5cc for valve reliefs in pistons and .040 for a head gasket and compression comes in at 9.5:1 with a 72cc chamber.  That's a good pump gas number.  Promaxx heads come with 72cc chambers and a 185cc intake port.  No, they won't flow like AFR heads but they are $700 cheaper.  Hard to pass up that savings. 

I've been looking at cams like Imelda Marcos in a shoe shop.  Can't seem to land on one yet but today's favorite is a Summit Racing cam #1104.  224 degrees of intake at 0.05 and .466 lift on 114 lobe centers.  Ought to provide a big meaty powerband.

[Don5]

I don't know if you bought your cam yet but here is the recipe I used in my 400 back in the late 80's early 90's. I used Edelbrock Performer intake, Quadrajet carb, Long tube headers, Crane Fireball 2 290 cam .454 lift camshaft, 1.5 rockers with stock pushrods, hi volume oil pump, flat top pistons and stock heads. This set up really made the truck come alive. It ran great, used pump gas and would set you back in the seat when you needed it too. It was also very reliable. I loved it. I suggest you look at camshaft with similar specs. 

[gwcrim]

I looked for that cam and it appears that it went away.  It's a mid 80's design and no longer available. 

This one turned up in my search.  Howard's 112581-08.  It looks like it's designed for a 383-400 more so than most.  There's a good bit of overlap but a bigger engine can handle it.  Not so sure about the torque converter situation, though.  I don't want to go over 2000 and they recommend 2400.  At some point, streetablility has to win out.  Pump gas and no high stall seem to by my limit.  That still leaves plenty of room for fun.

[roundhouse]

2k to 6k RPM?

You drag racing?

I usually shift at 3000 unless I'm In a really big hurry

[gwcrim]

See, that's my problem.  I keep nudging my build upward. I'm an old drag racer and old habits die hard.  I keep telling myself it will never see the strip but before you know it, I'll be adding exhaust cut outs and tossing slicks and a jack in the bed......  I know myself all too well. 

My big concern now is making it unpleasant to drive around town.  I'm looking for that fine line.

[Engineer]

I'm tellin ya man......

427 with 049 heads. An asphalt ripper with mild manners.

[morrow07]

I have a street driven 406 pushing 500 hp. I can sit in traffic with zero cooling issues, and take it on road tips without a hiccup. Mind you this is with a 3000 stall. Stick with the small block and you won't regret it.

Sent from my C771 using Tapatalk 2

[gwcrim]

Engineer, ya gotta do a cost/benefit analysis.  How much would those extra 20 cubic inches cost in dollars and weight vs the gains.  SBC parts are pretty darn cheap in both cases.  I do love a good big block though.  There's no substitute for cubic inches, hence the biggest of the small blocks for this project.

[gwcrim]

Last Friday I took the plunge and ordered Promaxx heads direct.  Steam holes and shipping for $825.  Next up, cam selection.