[Kirk]

My goal is to build a dead-reliable, drive anywhere, Pontiac 400 that will hold up for a bunch of miles. I am not going for high performance, just similar to what a stock 1971 engine would have. Stories of lifter failures and “China” parts that fail have me wondering.
Do I need a roller cam and all that entails?
What compression ratio is okay to avoid pinging on 91 or lower octane.
The ignition modules in my Accel HEI fail occasionally, is there a better, longer lasting choice for ignition/distributor?
I have a 1971 block with 96 heads going into a 1972 lemans

[Goatracer1]

First of all, what's it going in? You may have answered your own question. Build a copy of a stock Q-jet carbed 1971 400 engine. Keep the compression under 9.0 to 1 with a 096 or 097 cam. It will have good pickup and reasonable economy. I personally have not had any problem with cam/lifter failure (knock on wood). Maybe because I don't build engines that need high valve spring pressures. If you really want reliability go back to points. They worked well for 75 years. There are no electronics to screw up. If they close up on you, you open up with an Allen wrench and go on your way. I know everyone will sell you more performance and newer ideas but this is what works for me. Good luck with what ever you do.

[Kirk]

Thanks for the input!

[indymanjoe]

9.5 compression is what seems to be a good pump crappy gas compression ratio. i went with factory hei compared to points. no particular reason. just seemed cleaner to me. keep a spare module in the trunk and all is well. 96 heads are a good start. i also ran 96 d-ports with a HR cam so i cant comment on a flat tappet cam.

[steve25]

While the 71 96 casting heads flow good enough to make 350 Hp even without headers they will not get your compression with a 400 up into the 9 to 1 range without milling them .060” on the deck and the intake flange.

Aftermarket pistons with only two valve notches will help out a tad in the compression department.

I would get a Crower 60240 cam and lifters and send them out to get cryo treated.

Next rebuild the heads top to bottom with new guides and new valves.

Get Crower 68407 springs and new Kepler’s.

[DOC]

I built a low compression motor for my wife’s 69 bird. Dead reliable. Idles like a fuel injected car. Supports AC and a 5 speed easily during any weather.

77 400 block / 6x -8 heads / exhaust manifolds,/ qjet and cast intake/ HEI/ summit 2801 cam /. Used valve spring to keep the pressure low. 3:23 gears. Pulls to about 4500 RPMs. Runs on the lowest octane fuel with no detonation. Very comfortable at highway speeds and never overheats even In stop and go traffic with ac on.

I spent a lot of effort on being balanced well and tuned well. Vs how much power it can make.

It does have 2 1/2 dual exhaust with Pypes violators muffler s. Sounds more go than it really is

[Kirk]

Originally Posted by DOC

I built a low compression motor for my wife’s 69 bird. Dead reliable. Idles like a fuel injected car. Supports AC and a 5 speed easily during any weather.

77 400 block / 6x -8 heads / exhaust manifolds,/ qjet and cast intake/ HEI/ summit 2801 cam /. Used valve spring to keep the pressure low. 3:23 gears. Pulls to about 4500 RPMs. Runs on the lowest octane fuel with no detonation. Very comfortable at highway speeds and never overheats even In stop and go traffic with ac on.

I spent a lot of effort on being balanced well and tuned well. Vs how much power it can make.

It does have 2 1/2 dual exhaust with Pypes violators muffler s. Sounds more go than it really is

Like these ideas, thanks!

[Kirk]

Originally Posted by steve25

While the 71 96 casting heads flow good enough to make 350 Hp even without headers they will not get your compression with a 400 up into the 9 to 1 range without milling them .060” on the deck and the intake flange.

Aftermarket pistons with only two valve notches will help out a tad in the compression department.

I would get a Crower 60240 cam and lifters and send them out to get cryo treated.

Next rebuild the heads top to bottom with new guides and new valves.

Get Crower 68407 springs and new Kepler’s.

Thanks for the ideas, helpful!

[Tim Corcoran]

The 67 GTO 400 360 HP engine came from the factory with the 068 cam. This is a mild performance cam but improved performance over other factory cams. This cam works well with 9.0 to 9.5 compression even though the engines came with around a little over 10:1. This would be a very reliable cam and many thousands of GTO's came from the factory with this cam.

[peters23]

Originally Posted by DOC

I built a low compression motor for my wife’s 69 bird. Dead reliable. ... Runs on the lowest octane fuel with no detonation. Very comfortable at highway speeds and never overheats even In stop and go traffic with ac on.

What compression do you have to be able to run on low octane unleaded? Tx!

[Joe-Touring]

Originally Posted by peters23

What compression do you have to be able to run on low octane unleaded? Tx!

The general rule of thumb I’ve heard is to move the compression ratio decimal over to the right. ie 8.7 for 87 octane 9.1 for 91 octane.

To get more specific, most will say 9.5:1 will work for premium gas. So there’s some leeway, around 1/4 of a full point. 9.0:1 would probably be fine. But as always, all depends on cam selection, carb/ign tune, rear gear ratio, vehicle weight etc

[DOC]

I’m at 7.5 I think. It had the chamfered pistons with 4 valve reliefs and 6x-8 heads. No porting and standard felpro head gasket.

[vertigto]

@9.5:1 on my 400 (406) rebuild, slightly bigger Ultradyne/Bullet cam 400+hp/480+trq...no issues with 91 octane (ethanol-free). Thinking I could probably get away with 89, but usually get 93 down the street.

[Joe-Touring]

Originally Posted by Kirk

My goal is to build a dead-reliable, drive anywhere, Pontiac 400 that will hold up for a bunch of miles. I am not going for high performance, just similar to what a stock 1971 engine would have. Stories of lifter failures and “China” parts that fail have me wondering.
Do I need a roller cam and all that entails?
What compression ratio is okay to avoid pinging on 91 or lower octane.
The ignition modules in my Accel HEI fail occasionally, is there a better, longer lasting choice for ignition/distributor?
I have a 1971 block with 96 heads going into a 1972 lemans

I had a 71 400 w/ 96 heads in my car before the current 326. The 400 ran pretty good compared to the 326. Sounds like you just want a cruiser, so I'd recommend stay pretty conservative with the cam choice. Those heads cc out to ~96ccs, your compression ratio after a rebuild will probably only be around 8.5 to 1, which is very happy with 87 octane.

Are you doing a full rebuild? Overbore/pistons, etc? Or just freshening up the heads and adding a cam?

Either way, I'd stay away from any of the XE style cams out there. They have more aggressive lobes and are therefore more susceptible to going flat. I had an XE262 and it ran fine, but flattened a lobe within a few thousand miles. The Crower 60240 cam is said to be a good low comp 400 cam, but still has fairly slow lobes. Also buy good lifters. The Hylift Johnsons are what seems to get recommended around here. Also the Crower Cam Saver lifters.

If you want to spend the money, a roller is great, but around a $1000 upgrade. I went with a roller on my current build.

As far as the distributor, I like my factory points dizzy. Been very reliable for me.

[android 211]

I built a .060 over 400 with the Summit 2801 cam and 6X-4 heads. It had the standard log manifolds and cast iron '72 intake with a Rochester 4bbl. It was in a automatic (turbo 350) 67 Lemans with the 2.78 rear.. HEI It was a lot of fun to drive, it would hit 90 climbing long hills and got 17-18 mpg on trips. It had stock size tires, open element air cleaner, 2 1/4 inch duals with Dynomax mufflers. It ran fine on 87.

[HWYSTR455]

I would say stay in the 9.0-9.5 SCR range, can easily run 91, 89 in most cases, even if quality slips. But I would run 91 all the time, even at lower SCRs, the gas is just plain better quality.

Prep block & heads properly and run the best valvetrain you can afford. Zero deck is good, but feel too many put a heavy spin on that when it won't make that much of a difference. Yes, in extreme cases it make more of a diff, but generally, not a lot.

Tank & check block, line hone, deck cleanup, and ensure cap fitment. Doctor for better drainback is a good bonus.

Forged pistons and rods, good hardware, windage tray and an oil pan with good oil control. Use threaded valley plugs. Aftermarket dual plane and HEI is fine. BRAND NEW wires and plugs.

Same with heads, tank & check, surface cleanup, guides, 1 piece SS valves, and a good valve job. Open up pushrod guide hole, use screw in studs, doctor drainback, upgraded valve seals, good springs and retainers. I'm a firm believer adding seats is not needed and have proved that by example many times over.

If you can afford a HR setup that's good, but not mandatory. Pick a grind that has an lsa of 114 or so, and lift under .550, .480 - .500 range is fine. Keep the @ .050 specs under 230-235. High 200-teens, to high 220s is fine. No need for cryo on cam or 'special' lifters, just buy quality parts. Don't skimp on rockers, at least aluminum full rollers.

Make sure your cooling system is 'right', good/new radiator, pump & clearanced, timing cover, pulleys, belts, etc.

Use good gaskets, I'm a cork/paper guy, but really any name brand works. For iron heads, I like 1016 Fel-pros for iron heads, but been a while since I've done an iron head build. Just don't use 'regular' production line stuff.

Butler pumps out many engines and parts, the parts they offer are basically a baseline, sure they don't like callbacks. You can call and ask if you have any questions, it's not often they will steer someone wrong.


.

[Squidward]

Originally Posted by android 211

I built a .060 over 400 with the Summit 2801 cam and 6X-4 heads. It had the standard log manifolds and cast iron '72 intake with a Rochester 4bbl. It was in a automatic (turbo 350) 67 Lemans with the 2.78 rear.. HEI It was a lot of fun to drive, it would hit 90 climbing long hills and got 17-18 mpg on trips. It had stock size tires, open element air cleaner, 2 1/4 inch duals with Dynomax mufflers. It ran fine on 87.

I like this setup for what OP described.

Even the Summit 2800 cam would be a very friendly option that would be a performance upgrade over stock. I ran one in a 350, liked it.

Qjet, HEI, mild cam. Makes for nice super reliable cruiser. I am currently working backwards to get closer to a similar goal.

[Formulas]

For building a good cruiser engine you want low end torque.

Compression builds torque at every rotation of the crank if it was my goal to build a cruiser 400 i would use 85ish CC 1970 and prior 350 heads, good valve job ports blended

the smaller valves and pressed in studs not a problem in this case

2800 cam.

why hamstring yourself out of the gate with needlessly low compression

[HWYSTR455]

Very true on SCR, you NEED it, especially with a cruiser or mph conservancy, even new cars have more SCR.

Remember, 'performance' MEANS efficiency, regardless of what the purpose of the build is. The term 'racing' is like saying 'NOS' for N2O, means you don't understand the meaning of performance.

'Stock' cars back when these cars were 'new' required regular maintenance, and mostly due to short cuts the OE's took to penny pinch. Compare an owner's manual maintenance schedule for older cars to newer cars and you will have a light bulb go off.

I still say regardless of build, do screw in studs and big valves, you may change your mind in 50k miles and you would be 'stuck'. For the couple extra bux you won't even feel it when spending for the other stuff, if it's even an added cost. And even with a turd cam the studs can walk just from shear age.

I remember people even on daily drivers back in the day hitting the tops of studs to drive them back in when the cars got older and made noise. Car back then were near worthless at 100k miles.

The 2800 cam falls flat at 4500-4800, yawn. Again, if you just want a car to drive around town it might be ok, but you will get bored with it very fast, especially as even base hondas and nissans kick your butt and laugh at you.

If you want a 'cruiser' then money would be better spent on an OD trans. Or a used Honda or Nissan.


.

[SD455DJ]

Here is a 400 build with the good ol' Summit 2800 cam.

"Dan had a good dyno session today with the W72 400. Dan rebuilt the original numbers matching engine with .040" over Icon forged pistons w/4.5 cc valve reliefs that are .006" out of the hole and with .045" x 4.328" Felpro head gaskets to provide .040" quench depth. The 6X-4 heads were minimally cut for trueness and measured 92.45 cc's average for a final static compression ratio of 8.75 to 1. Dan replaced the cast rods with forged Eagle H-beam rods. New 1-pc valves (2.11/1.66) with CC dual springs were installed. A Summit 2800 cam (204/214/112 @ .422”/.444”) with new 'old' Crane hydraulic lifters along with a new Melling 60 psi oil pump. The one modification was the use of old factory D-port ram air exhaust manifolds with the 2.1" outlets with Pypes 2.5" mandrel headpipes. The original 17058263 Q-jet on the factory cast iron intake with the EGR system and plumbing were reinstalled."

"The base runs were made with 42 degrees total timing in by 3000 rpm, 45 primary rods/74 jets/CH secondary rods on an I hanger. The 3rd (and best) base pull made a corrected 360.3 hp @ 5000 rpm/456.1 lb-ft torque @ 3600 rpm (351.2 hp/444.5 lb-ft uncorrected). The correction factor was a low 1.026 as the weather conditions were very good...low humidity, high barometer, and very cool temperatures (65 in dyno cell). After rejetting the carb to 40 primary metering rods/72 jets/DA secondary rods on an 'I' hanger (same total timing at 42 degrees), employing the 'big' dyno room dumps for the headpipes, and installing the air cleaner base, the max hp jumped to 371.4 hp @ 5000 rpm/459.2 lb-ft @ 3600 rpm (362.0 hp/447.6 lb-ft uncorrected) on the final pull (#14). The highest torque reading was on pull #13 at 460.3 lbft."

It runs great on 87 octane gas too! He'll use 93 octane if he decides to race it.

Dennis