Engine assistance needed
 

Trying to provide assistance to a gentleman in Germany who is having less than desired performance from a number of aftermarket modifications to a 400 engine in a 1967 Bonneville.

Apparently, his original camshaft failed, and he could not find one in Europe. A mild performance cam was installed. Performance was not consistent with that of the original, so a aftermarket performance intake was installed, which did not help the issue. Next step was to replace the carburetor with an aftermarket; and the car still does not perform even close to as well as he believes it should. He thinks he has lost roughly 100 HP.

I suggested returning everything to stock, which he is going to do, IF he can find a stock camshaft. He still has the original intake, and I think I can take care of the carburetor issue, but the camshaft location is out of my area of expertise.

Can someone suggest a reliable source for a STOCK Pontiac intake for a 1967 400 4-barrel Bonneville that I can forward to him?

Thanks in advance.

Jon

It’s tough to suggest some possible solutions in your situation. First off, more specs (camshaft, cylinder head #s, last engine refresh, current timing specs, exhaust, carburetor) are needed. Adding-changing parts to gain a desired outcome is expensive and typically useless until everything else is sorted.

All of the 400 CID big (B) body cars in 67 still used the 389 type heads and as you might already know a AFB carb.
As such with these type heads it’s best to stay away from aftermarket cam’s of more then .450” lift due to the pressed in rocker studs.
Ask me how I know this!

The automatic cars in 67 all used the 066 cam and the manual cars used the 067 cam.
Both of these cam’s where no more then .414” lift.

The sponsors of this site (Ames performance )
Stocks a 066 cam in there N522.
I would also recommend changing all 16 push rods at the same time.
They are part number N510.

During cam break in he should over fill the pan by 2 QTs to guarantee good oil splash to the cam.

His rockers and rocker balls should be closely inspected and the balls must stay matched to the rockers they came from.

Many times I have seen a cam and lifter failure being blamed on these new parts when what started the whole mess was a rocker , after a short while coming loose because the rocker and ball where not kept together as a matched pair when the heads where disassembled.

Also all the rockers should be removed and the rocker studs should be inspected for ware grooves and ridges where the ball rides.

Instant great loss with new parts that are not light years different from prior build suggests to me cam timing, Perhaps suggest a compression test and real cam numbers

yeah i don't see why an aftermarket cam with, say, 210 degrees or fewer @ .050 on the intake side and a 112 or wider lobe sep would run poorly unless it was not degreed properly or something else was wrong.

How about something simple like the throttle linkage not opening up all the way?

yeah what cam and intake does he have now, and is the power loss at lower RPM, higher RPM, or across the board?

Thanks to all who responded.

This all started with the failure of the original camshaft, and the shop was unable to acquire one in Europe.

The gentleman wishes to return the engine to its stock configuration, so was interested in a camshaft source.

Steve - I will pass your entire post to him.

Again, thanks to all.

Carbking what does this fellow have currently for a aftermarket intake?

Fuel is?

Aral 102 is available (at certain Aral gasstations) in Germany, it's expensive (approx. $8 per gallon) but it's available. It has a (converted to PON) 97/98 octane rating. Its ethanol free as well.
Good stufff.

Rock Auto offers many of the original Pontiac camshafts. There are services available to get one shipped overseas. I done such for quite a few of our Pontiac friends over the years as I ship to Canada and overseas daily and familiar with Customs requirements and the best services, rates, etc.

I'd also add that when you "loose" a camshaft/lifter millions of tiny particles of metal get pumped thru your engine. The filter doesn't catch all of it so many other parts of the engine suffer damage including piston rings and cylinder walls. This lowers compression and hurts engine power and performance.

One also has to be smart enough to know that if you change ONE part, like a camshaft, and EVERYTHING goes to chit for engine power and performance, buying fancy intakes and carburetor is NOT going to help in the least. They need to go back and fix the root issue first........FWIW......

I'm on the cam timing band wagon, think that's a very likely cause.

Pics would be great too, something may jump out at some following this thread.

Might want to check carb to intake gaskets etc, may be something amiss there.

Vacuum lines and ignition timing is another area, maybe the balancer is slipped.



.

Well, we have been having internet issues (it often doesn't work), and have had some difficulty communicating.

The gentleman that I am trying to help is actually trying to help another gentleman, so initial information may have been less than correct. The camshaft may be a RAIV clone, which obviously is going to require carburetor modification. Don't really think this is a good choice for an otherwise stock Bonneville 400. But it is what was available in Germany.

I did suggest that before doing anything else, the harmonic balancer timing mark should be checked, to see if a timing issue is present.

Have not heard back as of yet.

Having rebuilt a number of European vehicles in the 1960's and early 1970's (before being bit by the buy-American bug), I can attest to the difficulty of finding obsolete parts for a vehicle not native to one's country. Sometimes one uses what one can find. I sold one vehicle that I wish I still had because at the time I did not have the skills to fabricate a non-existant part.

Apparently, after the cam change, the car did not run well, and additional parts consistant with the cam were thrown at the engine.

The gentleman with whom I am corresponding sounds like a car person, and will let me know the condition of the timing mark after it is determined.

Again, thanks to all who responded.

Jon

Well if true a raIV cam in 389 will need more then just carb modifications, other problems will be,

1) a dog with less then 10.5 compression.

2) in a B body that weighs over 4400 lb and with 2.93 to 3.23 rear gears will be even more of a dog.

3) that cams .469” valve lift may make for mechanical problems like coil bind with the valve springs.

The exact details need to be nailed down .

Did the 061 big car heads have the 389 valve angle? I pulled a 2bbl 400 originally from a 67 Catalina that had the 061s. The 400 block had the early valve chamfers but I don't remember the heads.

What's the deal with not getting parts for American engines? Will RockAuto and summit not shipped to europe?

All 1967 blocks has the early valve chamfers regardless heads used.
The open chamber 061 heads uses the same valve angle as the 670 heads.

Well there was a change over point somewhere.
Those added mid year changes a long with the normal Aug change over to the next years model line can really muddy the waters.

Pontiac had a huge array of engine options in 67 since the 326 was still in production.

From what I just looked at a 1967 B body 400 4 bbl could have been sent out the factory doors with the 061 or the 143 389 type heads, and even with the same hp rating.
The only thing for certain is that if you had a 400 2BBl with 10.5 comp, and the 254 cam and not the 066 cam then for certain that motor had the 143 heads.
All the other lesser comp 2BBl motors with the 254 cam got the 142 heads .

“The only thing for certain is that if you had a 400 2BBl with 10.5 comp, and the 254 cam and not the 066 cam then for certain that motor had the 143 heads.” I believe this statement is incorrect? Our 67 has 061’s & 254 cam on 290hp 2 barrel motor… 58k mile car

The #143 head was superceded by the #061 in mid 1967 production to allow the use of pushrod guide plates.

An early YC, YD 2-bbl 290 hp engine would have the #143 heads while a later XV, XU engine has the #061 heads.

HTH

I would have him verify cam is installed in the correct position. If it was one tooth off it would be down on power for sure.

Could you advance the cam and use rhodes lifters to move the powerband low enough to improve low speed manners?

The remaining challenge is what to do about the pressed-in studs on 061 heads, if he didn't want to pull the heads?