Technical 400 Pontiac engines.......different than Shivel-layz ,right?

Buddy just came across a mid 60's GTO for a steal. Been sitting up for 20+ years.
(He got such a sweeet deal he's afraid to answer his door for fear its the cops coming to get him for theft!!)!
Anywho neither of us know much about 400 Pontiacs but I KNOW there are several in here who DO!
Do these engines perform better with a tighter LSA 108*-110* and moderate duration?
Do the stock 400 heads need much work for a peppy street engine?
His 'semi' plan is to keep it 93 octane friendly but keep the 10.75:1 CR from the factory. (Snotty cam to bleed off some of the low RPM compression to stay out of spark knock/rattle)
Wanna keep the lift under/around 500 to save the valve springs(No wild lift 6-7 hundred)
It's a 4 speed car so "convertor worries" ain't gonna be an issue!
Any of you Poncho.....Pontiac....GTO.....Tin Indian...Goat lovers... got any skool'in fer us?
6sally6

 

Aluminum heads with the same cc's and he won't need to do anything.

 

Years ago crane made a beautiful cam that would be perfect.

Don't remember specs but it had 467 and 494 lift. I'll try to check

I used it in 2 engines and another buddy ran one too once he drove 1 of my motors.

 

Here you go
Crane Cams 283801

Awesome street cam. Actually would wad the rear wheels in the tires and scare you to death first time it happened.

 

I am in the same boat with my gto, I went with a copy of the “068” Pontiac cam. wide Lsa (115) for a better vacuum. If you go to big you will lose the lower end power ( or go with 3.90 rear). My car in stock form ran real well years ago. I have not run this motor set up yet, so I can’t help you much.

 

Not a Pontiac guy, but have a friend whose a diehard Pontiac guy. He tells me that lifts around .500"-.525" that would be somewhat large on a SBC are considered very large on his big Pontiac.

 

Yep, I have built a few Pontiac motors and the main thing I can say is that a cam that would be a decent street grind in a Chevy was too much in the last 400 I built. Other than that, I don’t consider myself any kind of expert. I would ask for help from a cam company with the whole combination in mind if it were me.

 

A tight LSA is not going to mix well with a high CR Pontiac engine.
Also the Pontiac valve train is non adjustable from the factory,if you are going to increase lift, you are going to have to change a few things.
Lots of on topic info, in the “street” section here-
http://forums.maxperformanceinc.com/forums/index.php

 

If it still has stock cast iron rods, they won't stand being revved over the factory redline, which I believe is 5,250 RPM. That was really the main weakness of Pontiac engines.

 

pontiac valvetrain is not a problem, just poke newspaper down over the tops of the rocker studs, take a small grinder and lightly smooth the tops of the studs. Next put a set of mr.gasket posi lock nuts and your done.

Built 7 pontiac motors and did this to all of them and adjusted for zero lash. Lost track of one motor I built at over 127,000 miles and was still running great.

The old 068 cam is obsolete tech, I agree it's a easy cam to throw into something but there are better options out there. On my motors I like them around 110 to 112 centerline, still gives around 12" of vacuum or better along with a nice idle at around 800 to 900.

the crane cam is great for a manual with 3:55 gears or an auto with 1800 stall and yes 3:23 to 3:55 gears. this is were the cam really lives, of course you can run higher gears but If I'm camming a hotrod I want a bigger cam then stock and more power to go with it.

.

 

Wider LSA than FoMoCo or Chevy..interesting. Would ARP rod bolts give some insurance above 5500 RPM?
May need to do some "smooth'in" on those chambers to get it to play nice with 92 octane gas? I tink CR is 10.75:1 on 67 400 engine!?!
Very interesting
Thanx
6sally6

 

Yes they will.

 

The 068 cam may be old tech, but it still works pretty well (and it makes the engine sounds good, which is also important for street use. )

Having said that, does it need to be rebuilt? Even if it's been parked for 20 years, the engine internals may still be in good shape. Check it out first and see if it will run before spending money.

 

Pontiac’s have machined combustion chambers already. The rods are cast so arp bolts would hurt be might not help, Pontiac’s are torque motors not high reving,

 

Before I would hop up a “real” mid 60s GTO, I would check prices on a restored model, do a clean up, small restore & sell it. Then use that pile of cash to buy a real hot rod

 

IIRC the later SD455 sported much improved rods- finally. The was also a Trans-Am race engine, which was a destroked 400 at 303 ci- and was a genuine screamer

 

Lots of good tips here but really we don’t know what you are working with. What heads, block, trans, etc. What’s the intended use. If I were him I’d start with these two books. You will find crazy prices on Jim Hands’ book because he knows how to build fast Pontiacs . If you can find one of his books under $100 buy it. Pete is no slouch either running super stocks for years. ID everything first IMO so you know what you have to start with. Regards, Randy




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Jim Hand's book has been out of print for a long time, but Rocky Rotella's book is still widely available and contains some information that's been updated since Jim's book was written: https://www.amazon.com/How-Build-Max-Performance-Pontiac-V-8s/dp/1613254741

 

Agreed. I have Rocky’s as well but not quite what I thought the OP was after but sure throw it in there. Jim’s book is still very available even new, just not cheap. This one has 10 watchers (and I doubt they are all sellers. Randy

https://www.ebay.com/itm/282197110228


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The thing to keep in mind with the 400 pontiac engines is to not swap Ram Air parts onto the engine piecemeal,the non RA rocker are 1.5 ratio while the RA pieces are 1.65,also the RA heads use longer valves allowing a taller installed height on the valve spring.The stock non RA valvespring installed height is fairly short and will reach coil bind before you reach .500 lift.There has been many a pushrod bent because someone swapped an 041 cam and the RA rockers into a non RA engine,while the 041 cam has been used successfully with the 1.5 rockers you can't do both without pulling the heads and swapping in longer valves and the appropriate valve springs.The Hand and McCarthy books referenced above will cover all that,they have lots of great info.

 

Jim Hand’s son is on here (the H.A.M.B.) and has been really helpful with answering a lot of my Pontiac questions. Hopefully he will chime in.


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Pontiac distributors rotate counterclockwise so don't put your plug wires in like a "shivel-lay". Lots have tried and failed.

 

If you are interested I can tell you what worked for me over thirty years ago. I had a 428 Pontiac in a 1966 Le Mans that was my daily driver. For two years I worked with the 428 while bracket racing. No engine dyno just ET slips. The 400 has a shorter stroke than the 428 so it should rev easier. After two years of racing this is what I ended with: Edelbrock Torker intake with a GM quadrajet and many jet and needle changes. On a flow bench the stock D port heads flat line at .480 lift. Best castings where #62 and #16. Back then the best Pontiac cams came from Lunati and the one I used was a "cheater" cam from Lunati that was for NHRA stock classes. I used the factory point type distributor with vacuum advance but was recurved for faster advance. Once you pick a cam and intake manifold start experimenting with headers. I ended up with JR headers that had 1 3/4 primary tubes and short collectors. I got sucked into the mind set that said Pontiacs are slow turning torque engines. Back then all of the Pontiac drag cars had long extensions on the collectors. One night I ran the car without the extensions and the engine really came to life. At the end I was shifting the car at 6100 rpms. Get a set of Chevy valve adjustment nuts that have a set screw. With the engine running adjust the valve to a point where the clatter just stops then go 1/8 turn more. I hope this helps.

 

Basically a 4 stroke internal combustion engine is a 4 stroke internal combustion engine. What makes one go will make pretty near any of them go.

The 400 Poncho was pretty stout from the factory even the 350 motor will surprise you. Both are GM and neither is Chebby in any world. You should be really happy with one. If I wanted to stay with the higher compression and iron heads I would certainly tighten up the lobe centers line and run with it. If compression rattle is still a problem you can always *spray it with a little methanol to make that go away.

*PM me and I'll tell you the poor man's way to do that.

 

I built a lot of Pontiac's, Jim Hand is my dad. What engine do you have, there are a bunch of 400's.
Summit racing makes a very good camshaft, the #2801. A friend runs a '65 GTO with a 455 and the Summit cam, 12.40@105 mph last fall.

 

Thanks for replying Joe. We don’t know anything yet about the engine...I’m sure they will let us know soon. Regards, Randy


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Good to “see” Joe! We were hoping you’d stop by!

Scott


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1967.........400..........original engine(or so 'they' say!)
6sally6

 

I used the Crower 60919 cam on my 462. I tried Rhoads lifters and it ran great but was too noisy. I tried the regular lifters. This is what I did to get it somewhat street able. I ran full timing at 38 no vacuum advance. If you remove the springs from the weights, the timing will go to 12 when shut off and stay there during start, once the engine starts the weights go out and your at full advance. Once I switched to a smaller duration cam was when it really woke up.. I think it was a Wolverine I switched to, it did have a intake lobe separation of 114. The one everybody has good luck with is the Summit 2801 in the 455..

 

Welllll. can't get Crower 60191 to come up!
Sounds like it want plenty of advance ....right NOW!
Was that cam ground with advance already in it or....straight up?
Thanx
6sally6