chrisneu68olds

I am researching building out a 400 CID (67 block) and I was having some thoughts that I wanted some opinions on. This will go into the '67 Cutlass/442 that I don't have yet, but I like to research and mull over things. Anyway...

A 1967 442 was rated from the factory with around 350HP@5000 which is pretty good, but what I would like to do is build a 400 that comes in around 400HP @ ~5000 using pretty much the stock configuration, same cam, pistons, heads, intake, etc, if possible.

I just feel that 400HP is about where I want it. For my needs, any more than that is simply overkill.

What I don't want to do:

1. Run a much more aggressive cam (I want it to have good manors and not require an 850 CFM carb just to idle the damned thing)
2. Run a compression ratio > 10.0:1 (Pump gas please)
3. Forced induction of any kind, fuel injection, or Tri-Carb (Tri-carb is too much of a pain)
4. Run a huge Holly DP carb (Can we achieve this with a Q-Jet?)
5. Run some odd-ball intake (Would prefer stock if possible)
6. Spend a boat-load on a crate motor or balancing

What I am willing to do:

1. Port and polish the heads
2. Run slightly larger valves
3. Run a slightly more aggressive cam, but I would prefer completely stock spec's.
4. Electronic ignition
5. Run a better flowing exhaust (but not straight pipes! I like rumble, not racket!)

My '71 Cutlass S had:

• A 350/4BBL with a cam that was pretty much 442 spec'd.
• No headers / 2.5" pipe to "cherry-bomb's"
• 350 diesel heads (Ported and polished with a very nice valve job)
• Started with Dual-point and went to Electronic ignition
• Q-Jet sitting on a stock intake
• A TH-400 with a medium shift kit and 3:55 gears (nothing to do with HP, just a point of interest)

...And it ran like a striped-assed ape on fire!

...so I think that it is possible to achieve my goal

I never dyno'd it (High school kids can't afford that) but I suspected that it was knocking on 290-300HP, maybe more, and if, BIG IF, it had more, I would not bet on more than 310HP and that may have been on a cool day when the stars aligned perfectly. I digress...

So gentlemen, and ladies, what do you think? 400HP from 400CID without breaking the bank or feeling like driving a drag car?

Thanks in advance!

svnt442

It's doable, but remember it's all in the heads. Do or have a proper port job done with good gasket matching on the intake side and port match the intake and you should be good to go. The head restrictions are what kill power more than anything.

380 Racer

Personally I think it will be tough to achieve 400 HP with your restrictions.

Can I ask how you used diesel heads on your 350 in your 71?

cutlassefi

[QUOTE=380 Racer;317694]Personally I think it will be tough to achieve 400 HP with your restrictions. X2

Can I ask how you used diesel heads on your 350 in your 71?[/QUOTE]

You caught that too huh?

You're really limiting your self on this build. You may have to make some concessions, either 400 hp or more non stock parts, your call.

Jmo.

72 cutlass455

Also what was the real hp of the 400 gm had a 10 to 1 weight ratio so a car that was 3500 pounds could only have 350 hp. Even if it was greater all you could state was the company line.

Run to Rund

If you consider a 240-244 deg at .050 cam to have good manners (not manors), and will run a true 10:1, you can definately do it, so long as the rest of the build is well done. I almost didn't answer after you wrote that you used diesel heads in a gasoline engine buildup. Inquiring minds want to know!!!

chrisneu68olds

@SVNT442 - It was pretty much in the heads. The ones that were on there had a 5-angle valve job with stainless valves and port/polish courtesy of my friends father.

@380 Racer / cutlassefi - They just bolted on with no issues, though the water jackets didn't exactly match up everything else did. The diesel heads had larger water jackets and larger valves from what I understood and that is why they were picked up at a junkyard for $50. The original heads were fine but these were selected for that purpose alone. Just the heads, not the rest of the block.

@Run to Rund - Good catch on the spelling...long day at the office yesterday.

It seems that we are kind of split here. I agree with 72 Cutlass455 that HP may have been understated. The consensus seems to be a firm maybe.

Thanks all, keep the thoughts coming.

Steve O

I don't think the diesel head would work on a gas engine, they have almost no combustion chamber and were something like 22 to 1 compression with a flat top piston...

The compression would be way to high even with the biggest dished piston you could find

Run to Rund

I expect the heads were gasoline type and someone told him they were diesel heads. Where do you put a sparkplug in a diesel head? The injection line hole or the glow plug hole, lol.

L69

The magic in the Olds motor happens when you work the heads. Also you didnt say whether you were using B or C heads and if they were big valve. I will assume C heads being a 67 and large valves. A good gasket match port job on the intake and exhaust along with a high polish on the exhaust will help considerably. Also gasket match the intake and have a pro set of porting bits as the runners are real long on an Oldsmobile. Also dont forget the bowl work, this is where everyone skips and they wonder why gasket matching their heads does very little for power. The valve guide boss needs to have lots of material removed and I usually shape them with a fine teardrop finish depending on whether the guides are oem or new bronze guides. Also make sure the opening just below the seat is close to the width of the valve as many people have new seats installed for larger valves and never remove the material, defeating the purpose. Dont forget to leave the lower bowl area a little rough to the touch for fuel atomization. With this kind of head work and say a w30 type cam with todays computer created dual pattern design, headers and a good dual 2.5 inch dual exhaust with highflowing mufflers (no flowmaster) you will be right around 400 horsepower.

chrisneu68olds

ALL
Complete BRAIN FART, I meant a set of MARINE heads, NOT DIESEL, I must have been drinking that night or something...

Talk about whatdafu*wasithinkin...How embarrassing!

chrisneu68olds

Sounds like a reasonable approach. I still have a lot to learn for sure since I have not turned a serious wrench on a car for quite a while, short of oil changes, brake jobs, and a few what-not's. I have not torn down and build up anything in years.

Thanks to you, and everyone for their input. As soon as I acquire the car (looking at Feb/Mar) I will start asking for more advice I'm sure.

Rickman48

Marine does make more sense, but I'm not familiar with them.
If it was me, to get that power with your restrictions, I'd look at what the NHRA stocker guys are doing, as they have even more restrictions and are achieving 400+ HP to run the numbers they do.
I think some of the other members know where/how to find them!
Good Luck!!

chrisneu68olds

It was my understanding that they were select because they had the larger valves than the stock 350 heads that were original. I took that one on faith from the person who did the actual head work. I would have asked him, but he passed a few years ago.

aliensatemybuick

I didn't see an 1/8 inch overbore and use of stock 425 pistons in your list of restrictions. Should get you halfway there by itself.

Run to Rund

Olds dyno'ed the 400 Tri Carb engines destined for the factory 54 66 W30s a 412 HP. These engines had the 308 deg. cam.

L69

1/8" bore always scares me even though there is plenty of meat after the sonic test. Plus the 425 pistons are scarce and hard to find let alone expensive. How about a .060 overbore and purchase stock w31 350 pistons from summit for $360.00 Same height and compression will stay roughly the same with the overbore to compensate for the thicker head gaskets. (There is always the famous Mondello thin heads gaskets, waste of money if you ask me)

chrisneu68olds

What compression ration are we talking about?

L69

Depending on compressed thickness of head gasket ( I am estimating .040) and a stock deck height you will be around 10:1 give or take .25 depending on actual combustion chamber volume. This is also including a 4.057 bore with w31 flat top pistons. With the right tuning, a smooth combustion chamber and 93-94 OCTANE the motor will run fine and pinging will not be an issue.

GTI_Guru

If you are interested, I may very soon hace a complete 425 short block up for sale with 130K miles on it. Forged crank, and standard bore original pistons out of a 66's starfire.

I'm probably going to be pulling the engine out of mine to swap in my built 425, but i want to keep the heads & go totally through them for the bigger valves, etc.

I also have a complete 455 (1969 complete long block) up for grabs, but shipping either to the left coast from the midwest may make it a little difficult.

-Jeff

Run to Rund

I have a 425 short block, and a bunch of pistons/rods, but Albuquerque isn't near anyone, lol. I took one sb to Tx for the Zone show, and can take stuff to the Nationals in Iowa, but somehow, people seldom want stuff at times like that.

chrisneu68olds

@L69 - That is pretty much what I am looking for; Suggestions and ideas. The price point of $360 for pistons is pretty good. The parts inventory is going to take some cash for sure, but I am really scared of the $$ for getting the heads done. Like you said, that is where most of the real fun happens, the question becomes how much are you willing to pay for and how much fun can you afford.

I have not even begun the search for a machine shop that does good work at reasonable prices. I have talked some guys that say 'take it to shop a' and then others say, 'no, not shop a, take it to shop z, shop a is so sleazy, I would not let them turn a rotor.' (Live in the SF Bay Area guys,closer to San Jose, ideas??)

@GTI_Guru and Run To Rund - Thanks, I really appreciate the offer, but not quite ready to start collecting parts yet. But I will keep you guys in mind when I am hunting. I am shooting for Feb Mar to pull the trigger and buy the car.

L69

When you decide let me know and you can ship the heads to me or purchase a set of mine that have really good bowl and runner work. My prices are very reasonable and PM if you want more info.

captjim

Do your research, by the time you port iron heads and add larger valves and new guides, you will be pretty close to E-brocks.

L69

well when i port heads for myself I dont charge myself, also I only start with large valve heads. There is a significant cost difference. Considering edelbrock require small block ford roller rockers expensive head gasket unless you dont mind changing them every few years and cutom length pushrods. I sell highly ported heads for anywhere from 500-700, I do it out of my house as a hobby and only look to makearound 30 and hour as apposed to a shop who charges 70-80 an hour.

L69

edelbrocks are 1700 plus head gasket 150-200 plus purshrods 100 plus roller rockers 200 it easily becomes a 2000+ swap. Us olds guys are not blessed with the ease and price of chevy.

captjim

Just a suggestion, you might be surprised what a decent port/valve job will cost on 40+ year old iron heads, if you can even find siomeone to do it. A lot of shops will only port aluminum these days. There are plenty of used E-brocks for sale pretty reasonably priced.

chrisneu68olds

Oh I am researching believe me. I am not closing the door to any possibilities, but I am trying to get the best bang-for-the-buck.

rubeng442

Get the heads ported by someone that knows what he is doing and get a custom cam. And that might be just a start....

L69

Did you get the specs on the 400 E block I am currently building?