[Will]

I've asked this question before, probably several times, but want to ask again to see what some of the newer members might have to say and to see if anyone has new or fresh input on this topic. I visited Pontiac Dude's website the other day and saw the combo he had listed there for a 400 that ran in the 12.teens in a 3700 lb. car and that's pretty impressive but that setup is a little too radical for what I'm trying to accomplish.

Considering the following parameters, how would you build a 400 engine to get the most performance out of it: Going in a 3800 lb. car with functioning A/C, TH400 trans with 3000 stall, 3.23 or 3.42 gears (need to be able to cruise long distances on the freeway). Exhaust consists of Tri-Y headers into Flowmaster 2.5" pipes & muffler. Intake is open for consideration but MUST be at or near stock height & carb placement to utilize factory Ram Air components, which pretty much leaves the choices of Holley Street Dominator, Edelbrock Performer, Stock, or Edelbrock Torker I. Since long freeway trips are a probability, it must also run on pump gas. Given these restrictions, what cam would you use, what CR would you shoot for, and what else might you do to try to get as much power as possible out of it. What performance (1/4 mile) would you expect from this setup?

I'm asking more out of curiosity than anything else, and will enjoy reading whatever responses are posted.

[Will]

I've asked this question before, probably several times, but want to ask again to see what some of the newer members might have to say and to see if anyone has new or fresh input on this topic. I visited Pontiac Dude's website the other day and saw the combo he had listed there for a 400 that ran in the 12.teens in a 3700 lb. car and that's pretty impressive but that setup is a little too radical for what I'm trying to accomplish.

Considering the following parameters, how would you build a 400 engine to get the most performance out of it: Going in a 3800 lb. car with functioning A/C, TH400 trans with 3000 stall, 3.23 or 3.42 gears (need to be able to cruise long distances on the freeway). Exhaust consists of Tri-Y headers into Flowmaster 2.5" pipes & muffler. Intake is open for consideration but MUST be at or near stock height & carb placement to utilize factory Ram Air components, which pretty much leaves the choices of Holley Street Dominator, Edelbrock Performer, Stock, or Edelbrock Torker I. Since long freeway trips are a probability, it must also run on pump gas. Given these restrictions, what cam would you use, what CR would you shoot for, and what else might you do to try to get as much power as possible out of it. What performance (1/4 mile) would you expect from this setup?

I'm asking more out of curiosity than anything else, and will enjoy reading whatever responses are posted.

[PONTIAC DUDE]

Yo dude, I'll help ya out a little. Go with falt tops, the cast or Kieth black type flat top, 0 deck. felpr 1016 gasket. 6X of a 350, mill to 78-80 cc's. Cam in the 226/234 range with lift in the 500/525 range. Use 1.6 to get the lift for more ramp speed. Street dominator intake. 2800/3000 tight convertor. Hope this helps some. Later, http://PontiacDude.cc

[Will]

Thanks Pontiac Dude! What kind of performance would you expect from such a setup?

[All4Fun]

Hey Will!

I am in the middle of my 400 rebuild right now. Here is what I ended up with with my own research, machinist advice and help from this and other boards.

1975 Block bored .030 over w/torque plates and honed to a much finer finish than usual.

Keith Black 17cc dished pistons fitted w/Total Seal street rings.

Stock rods w/beams polished,resized and fitted w/ARP bolts

Crank .010 under on the mains and .030 under on the rods. Micropolished and oil holes chamfered.

Heads 1970 #13 72cc. street ported,gasket matched, Ferea Valves, Comp Cams 995-16 springs w/10 degree retainers and locks.

Camshaft 068 OEM w/lifters, Crane Energizer 1.60 ratio rollers.

Performer intake,Q-Jet,4 tube headers(Dynomax Ceramicoat),Flowmaster Force II exhaust 2 1/2",HEI recurved,MSD6A, B&M Holeshot 2400 converter, 3.42 limited slip rear, Turbo-350 modified and B&M 2nd stage shift kit.

This is going in my 1980 T/A. Mr.P-Body ran this combo on his analyzer and figured @397HP at 5000 and 462ft lbs. torque at 4000 with @9.5 to 1 comp.ratio

I'll be sure to let you know how she runs. Should be very streetable. Built it to try and keep up with the late models. Hopefully?

[Blackcat]

Will,
What year block will you be using? Heads what year? Casting #. 3000 stall is too much for a car that will be used on the highway. What compression are you looking for? Pump gas? You have a large amount of
variables to consider. Well here goes. 400 block 68-72 prefered. Casting# 62 heads (slightly larger chambers. Pistons the cast or forged ones with the shoulder for the 73 on up 400 engine. Stock rods/ARP bolts. Use the Pontiac RA3 cam It is available Or Summits Midrange cam for pontiac. Use 7/16 rocker studs. 1:52 roller tip rockers or 1:50 full roller rockers. The heads just need a good valve job. Installing hardened valve seats is a good investment for highway miles. On the bottom end use good quality bearings. Install a Mellings high pressure pump. Have the whole assembly balanced. It makes for a smooth running engine/longer lasting. Using moly rings makes for a stronger setup/quicker breakin period. Up top go for the Performer intake.(best buy for the buck) Use a quality Rebuilt Q-Jet on top. For a converter I would bo for the L-88 or 2000-2200 stall. Use the 3:42 gears(good for all around) You can install taller tires for the highway. Other considerations. Use the late 69 up timing cover with a new flow plate. Use a new stock balancer(still available). My combo may seem conservative to others. But you will be able to drive anywere with no problems. You might run high 12's with it. I have seen it done. It is the same combo that I use in my 72 truck. I had no problem beating a new Mustang with over 2 tons of truck (he even had a turbo whine) I just drove it to Wisconsin and back. I figure the combo makes about 360hp.

------------------
Mr. Z

[Will]

Thanks for the replies guys, keep 'em coming. I'm asking for how YOU would build an engine given the restrictions I imposed, so whatever CR you think should be run, cam, etc. One note, I don't think the 3000 stall is too much for freeway use. I have a Coan 3000 stall which is pretty tight below it's rated stall speed and it worked fine with my previous combo on the street and freeway. Also, this isn't a daily driver but a weekend "sunny day" cruiser that will see regular strip action in the summer with the occasional long-distance freeway trip thrown in.

Thanks again!

[Maniac]

Car: 1969 Catalina 4100#'s with driver.

Block: 69' 400 bored .040 over.

Federal Mogul rings and cast pistons 9:1.

Stock crank polished and turned

Stock conn. rods shot peened and resized for ARP performance rod bolts.

Summit Cam, 224intake/234exhaust @.050" .465/.488 lift.

69' #15 heads with pocket porting and gasket matched. Aftermarket pushrods, all else stock. 3 angle valve job, seats reground.

Offenhauser 360degree intake with Holley 600cfm vacuum secondary. 50cc accelerator pump. Stock fuel pump. K&N Velocity stack with 5" element.

Summit 1 5/8" Headers running through 2 1/4 exhaust and turbo mufflers.

Th350 with stall converter 500rpm over stock.
B&M Pro Stick. 10bolt rear with 2.60's (super highway gears lol).

All parts balanced.
All felpro gaskets.
92octane gas.

Stock engine numbers:
270hp, 400lbs torque with 8:1 pistons, iron manifold, puny 2 barrel, and single exhaust 2" pipe with manifolds.

Current numbers: not available
going to run it on Chassis dyno in near future. I know I freed up at least 100hp from unchoking the poor 400. But I'll have to wait and see.

Setup didn't cost me an arm and a leg and for that heavy of car it hauls balls. If you're looking to just do stop light racing this setup works just fine. You can always put in a bigger carb and cam and not have to worry about changing anything else, unless you go all out. It would be a great sleeper if I didn't have the monster Harwood aeroscoop mounted on the hood.



[This message has been edited by Maniac (edited 06-23-2000).]

[Maniac]

If I had my druthers I'd build the 455 setup I've already planned out except I don't have the 12,000 I need lol. As many will probably agree it's easy enough to get 400hp and 450lbs out of a 400 with bolt on parts and a little machine work. I wouldn't use a quadrapuke but that's just me. I'm not sure if summit still has their Intake/Carb/Air cleaner combo for sale anymore but that's what I got and it was around $390. You can find plenty of good parts for less on online auctions and even here at the parts wanted/for sale section.

[Gach]

Maniac.........quadrapuke ?....... that's the best one I've heard.........LOL.......god I'm pissing my
paints

[TinInjun]

<<Offenhauser 360degree intake with Holley 600cfm vacuum secondary.>>

Hate to tell ya this Maniac, but put a stock Pontiac 4V manifold, and what you call a "quadrapuke" on that 400 and it will run even better. Just one other question, why does it have a TH350 in it. The TH400 was the standard trans in the '69 Cat.
Factory numbers for your stock engine:
Comp ratio- 8.6-1
H.P.- 265 @ 4400
Torque- 397ftlb @ 2400

------------------
"Run wild with an Indian, not with the crowd in a Chevy"
Check out my restoration at http://members.aol.com/jetmech15/gto

[Skip Fix]

As I've been running a 400 for years in a 3800 TA and runs 12 teens in good air(not our normal 90 degree stuff here).
Here goes. Teens are going to be tough with those gears and A/C and pump gas??

Intake -another to look at is the Weiand one. It has bigger runners than the Performer and looks stock height, haven't flowed one though.


for high 12s and maybe mids
400 0.030 Trws or the new KB dished. Can machine a dish in TRWs (.100 deep 2.8 diam about 10cc. Stock rods magnafluxed ARP, SPS bolts. Balanced crank and assembly.

Heads-these are going to be the key to doing it on a 400.( friend ran 12.80s with a similar combo and a 428 shortblock and untouched #12s) 400 can run a little more compression than a 455 on pumpp gas but shoot for 9.5-9.7 max. Any D port will be close but should have pocket porting, the flow will all be close. Match your heads cc and pistons to get the compression ratio. 1970 #64 big valve or #15 small valve are about 87cc and just right with a flat top. #15 are cheap. Add some bigger valves and pocket port. #62s are about 75cc unless alot of milling.

I ran a Ultradyne 231/239 @0.050 on a 108 lobe sep with A/C but needed and idle solenoid on the Q jet. Friend with the 428 ran same cam on a 110. To do it again I'd have that one ground with a 112-114 lobe sep. esp with a lower compression ratio.(even ran a 249/255 on a 112 with A/C but had alot lower idle vacuum). The 1.6 rockers will let you use a lower seat duration and still get area for air flow so better idle and part throttle.

Intake- I ran and HO that WAY outflowed a Performer and the 78 stock intake. Friend with the 428 ran with a 70 cast iron intake.

The single planes will KILL the bottom end of a street 400. Drops the vacuum 2". Only time my power brakes didn't work great(they work even with a 259/262@0.050 solid roller in a 455 now)with a single plane and the 400. 60 ft times DROPPED 0.3 seconds. Now if it is a screamer strip 400 that's a different deal.

Keep on the small side for headers. No bigger than 1 3/4" tubes.

Swapping to a 400 from a 455 with the 3.42s definitely made th car more sluggish on the bottom end. The car will probably need 3.73s which still aren't too bad on the freeway with a 28" tire.

Good luck.

Skip Fix

[Will]

Thanks for all the suggestions guys. What do you think of the following combinaton:

Camshaft:
224/232 @ .050", 114 LCA, 108 ICL, .313"/.322" lobe lift.

Will run Harland Sharp 1.72 roller rockers on this cam for a gross valve lift of .538"/.554". Heads should flow 240 cfm @ .400" lift and 250-260 cfm @ .550" lift @ 28" with excellent low-lift flow and an I/E ratio of approximately 80%.

Shortblock consists of '71 400 block, align honed on mains with Milodon studs (2-bolt), +.030", zero decked, .020" crank from a '69 400, dished TRW pistons for 9.5-9.6:1 CR hanging on shot-peened and weight matched stock rods with ARP bolts, fully balanced, all bearing clearances set to .002-.0025".

Any other suggestions?
-Will

[Ken K]

I am also building a 400 with TRW forged flat tops. I have my choice of heads because I have a good selection of cores, I am leaning toward #48 heads because I can, even if I have to dish the pistons. I have a set of 1970 #15 heads and a set of 6X 4s but there still not 48s. I run 4 speed transmissions only because I hate automatics. I also like to run 3:55 rear gears. I have not decided on the cam I am going to use but I think the rest of the combo is a no brainer. I have a tri power, a cast iron 4bbl intake with a worked Quadrajet and a performer intake to choose from but nothing looks or sounds like a Tri Power.