1969 Pontiac

[Doktor_Bert]

Originally Posted By: OVERKILL
With flat tappet, definitely. With hydraulic and solid roller you can go much heavier.


Absolutely!!!!

However, always run the LEAST amount of pressure you can, based on the grinder's recommendations.

Also, have your springs TESTED at both closed and open heights, as we have seen springs incorrectly boxed, leading to disaster...

 

[OVERKILL]

An amusing experience regarding the last point: the custom in my buddy's 88 had some comp spec springs from the grinder. After a few years they started to float at around 6,500. But we didn't figure out it was float until after he sold the car, LOL!

The K-Motion K800's that I have for my SBF are ~500lbs open. Those were spec'd by Jay Allen, who used to be a pretty big name in SBF custom grinds.

 

[Rhymingmechanic]

Doktor_Bert,

Thanks for posting your 413 build. That gave me a nice trip down bench-racing lane.

I'm interested in what you did with the exhaust ports. Did you just mask them off and leave bare metal, or are they treated somehow? I always liked how easy it was to change plugs on a headered Pontiac, but not the burned paint on the heads. I also filed away your tip about the oil pump plate. I do remember it being thin.

69P,

For your intended use, conventional oil seems like the most sensible and economical choice. I share your concern about gasket leaks with Group IV and up synthetics at least--exactly because of the rope somebody else mentioned. The rear main seal in these engines is rope. Can anyone comment on their compatibility with synthetics? (BOP Engineering came out with a modern-style replacement about 15 years ago, but I don't know if they're still available.)

 

[Doktor_Bert]

Originally Posted By: Rhymingmechanic
Doktor_Bert,

Thanks for posting your 413 build. That gave me a nice trip down bench-racing lane.

I'm interested in what you did with the exhaust ports. Did you just mask them off and leave bare metal, or are they treated somehow? I always liked how easy it was to change plugs on a headered Pontiac, but not the burned paint on the heads. I also filed away your tip about the oil pump plate. I do remember it being thin.


The ports were cut by hand and then flow tested until the best shape was achieved. Then, templates were made to duplicate the results on the other ports. Exhausts are mirror polished with 400# sanding rolls.

What I think you are referring to is the OUTSIDE of the port where Pontiac's always burn the paint off. They were treated with Eastwood Hi-Temp Stainless Steel Coating and then the heads were painted...

389 Pontiac heads shown after conversion to screw-in studs and lowered spring seats...

 

[Doktor_Bert]

Pontiacs need oil...

Stock oil hole in block:

My modified oil feed hole - ALL galleys mirror polished:

M54DS Pump gasket-matched:

 

[Doktor_Bert]

Originally Posted By: Rhymingmechanic
The rear main seal in these engines is rope. Can anyone comment on their compatibility with synthetics? (BOP Engineering came out with a modern-style replacement about 15 years ago, but I don't know if they're still available.)


Stay with rope. Use the one made by Best Gasket and offered by BOP Engineering:

Best Rope Seal TOP - Fel-Pro Rope Seal BOTTOM:

Best Rope Seal installed:

 

[Doktor_Bert]

Originally Posted By: OVERKILL
An amusing experience regarding the last point: the custom in my buddy's 88 had some comp spec springs from the grinder. After a few years they started to float at around 6,500. But we didn't figure out it was float until after he sold the car, LOL!

The K-Motion K800's that I have for my SBF are ~500lbs open. Those were spec'd by Jay Allen, who used to be a pretty big name in SBF custom grinds.


Comp springs die pretty quick. Comp's profiles are very unstable and they require a lot of spring pressure. Comp's Billy Godbold has been quoated on this in several publications, but a trip to visit Nolan Jamora at Iskenderian will explain how a more dynamically stable profile can run higher rpm with less spring and heat!!!

We were running 6500+ in a flat-tappet 413 Pontiac with HEAVY valves and 280 lbs open pressure, thanks to the gentle lobe profile selected for us by Ultradyne's Tim Goolsby.

You learn a lot building endurance racing engines...


CHECK retainer to guide/seal clearance ALWAYS!!!

 

[Doktor_Bert]

Every job has to be clean...

Shown is a Pontiac 350 using 389 small-chamber heads. Fitted with a custom ground flat tappet camshaft featuring 0° overlap @ .050" valve lift, this engine, with headers and good induction, made 311.7 RWHP...

 

[67lemans]

Looks good Dr Bert.
To the OP, I would run either an HDEO or DS Defy. Used rotella in my 77 IH Scout with no issues.
Used Valvoline 20W50 in my 67 Lemans with no issues also (10 years ago). I most likely wouldn't do that today. (was in the mindset that thicker was better)

 

[ofelas]

69P - depending on bearing clearances/oil pressure at hot idle, it would do well on Amsoil's AMO 10w-40 or ZRT 10w-30.

Dokter Bert - nice pics. I will have to post pictures of my orange 413 motor one day

 

[Doktor_Bert]

Originally Posted By: ofelas
69P - depending on bearing clearances/oil pressure at hot idle, it would do well on Amsoil's AMO 10w-40 or ZRT 10w-30.

Dokter Bert - nice pics. I will have to post pictures of my orange 413 motor one day

YAY!

 

[Darren_L]