My Cam Research for the Experts Eye


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Long response :wink:

No plasma, I've got a gas rig, MIG and stick welders along with drill press, grinders, cutting wheels etc. The bracket pieces were cut with a cutting wheel, ground smooth and sanded. Slot was done with drill press, 5 holes connected with jig saw then smoothed with a small sanding roller.
I tack welded the pieces on the engine to ensure fit, then stick welded it all, smoothed the welds, primed and painted. I have a perverse enjoyment making stuff like this.

I've got engineering/construction ingrained from my career, so I apply the mindset where reasonable. Even a little pulley has factors to consider, so here's what I thought about....a peek into my brain....

I wanted something effective, relatively simple (considering the engine has no real provision for a left side idler), and low cost. From a load standpoint, the idler has to resist twisting and load pull from the balancer with consideration of clockwise rotation. The balancer is constantly grabbing and pulling at that pulley, lots of torque. IMO, the biggest forces would be from sudden acceleration and if the idler bearing fails, so my "design" needed to be robust enough to resist these forces. Weakest link is the bolt holding the pulley onto the bracket which is ok, very easy to change to a higher grade which I plan to do to replace the 8.8 graded chineseum bolt. Pulley center bearing is replaceable and is the almost universal 6203 if I remember right.

I decided against a common serpentine belt spring tensioner even though I could have installed a v belt pulley onto it, because I wasn't sure of the amount of tension. Serpentine is thinner and routes all over the place so my assumption was perhaps less tension. V belts have been tensioned by feel for decades, so keep it simple and don't spend a fortune. With that in mind I poked around and came across the Hayden 5950 at about $20 that was all steel and included its own mounting bracket. It fit into the left side space so I needed to come up with a mount that would work. I'd have to do this regardless.

So from that mindset I used material mass and triangular shapes for stiffness, assuming that there would still be some level of acceptable deflection. I decided on .25 plate for the mass and then looked to see how I could triangulate the bracket. One bolt at the WP housing and 2 bolts at the engine block/head gave me this triangle. The top part of the bracket is bolted and the bottom half has the two braces welded into place, its all very rigid and of course allows the idler bracket to arc back and forth to install and tension the belt.

The proof will be in the operation, but I wanted to come up with a reasonable design that addressed what I considered as possible failure points. I get it - its just a little belt pulley - but I'd rather not throw a belt or worse, have this thing get pulled into the balancer pulley. This whole (tedious) second-time-around build has been based on ensuring I've done everything I can to update/correct/check both function and appearance.

As mentioned, a long-winded answer!


The Grumpy Grease Monkey mechanical engineer.
Staff member
" I have a perverse enjoyment making stuff like this."

your not alone in feeling a sense of accomplishment when,
designing, making, and using custom fabricated components like,
headers, oil pans and accessory brackets


Staff member
Thanks for the response! That wasn't so scary of a look into your
brain, it looked pretty normal from my perspective !!!


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Idler is finished and installed, I'll remove the blue tape before I put the belt on. Speaking of belts, I measured both so it's pretty straightforward now to go get 2 new belts.

A nice coincidence was that the idler lines up with the other pullies. I didn't have to modify the spacer, just swap the crap pulley bolt for a real one lol. I'll still check alignment after it's running. IMO it was worth the work to add the second belt/idler.

Holley 850 is almost back together again.


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A little revision on the electric fuel pump control, no pics.

For years, I had used an oil pressure switch as a failsafe to shut down the fuel pump. I understand that the engine may continue run until the bowls are empty, but I chose that option vs immediate shutdown of ignition. The reason (for me) is that if there's a glitch somewhere in normal operation, using ignition kill, the engine shuts down immediately which can be bad if you're in the middle if the road.
In my case I use extremely bright red led's that activate for no oil pressure and fuel pump off. The oil pressure light is pretty standard but the fuel pump light gives you time to pull off the road before running out of gas in the bowls. All are pretty easy circuits to set up using 5 pin relays.
What I never liked though, was that I needed a momentary switch to prime the fuel system if the car wasn't used for a while, and the oil pressure sender and switch setup looked clunky, also took up a lot of space by the header.

I came across this the other day and have decided to install it:

It allows for 3 second key-on priming, then uses tach signal to run the fuel pump. In my case the controller will energize the fuel pump relay so overall it's a pretty minor wiring change. Everything to the pump itself stays the same, including control of the pump-off relay/warning light.

I think this is a clean way to control the pump.


The Grumpy Grease Monkey mechanical engineer.
Staff member
keep in mind ALL electronics and relays
(especially those subjected to engine heat and moisture )
tend to be highly MOISTURE and HEAT SENSITIVE


Well-Known Member
Plenty of protected space inside the car - module will mount above transmission tunnel under the dash, in front of the center console. It will mount to the underside of this tray assembly.

Slight rabbit trail.....I'm very picky about electrical so I prefer to make all the wiring from scratch, another perverse enjoyment of mine. I keep detailed diagrams and wire ID routing so it's easier to verify routing and connections. All connectors are weatherpack.

Anyway, that tray is intended to support wiring running under the dash, and it provides connection points for alternator charge cable and power distribution, both of which end up at the trunk mounted battery.

I also made up two separate fuse/relay blocks, one for ignition source power and one for constant (battery) source power. They both include circuit breakers at their main connection feed. One is under driver side dash, the other is under passenger side dash. These are also diagramed out on paper with all fuses/relays and wiring ID'd.

Made the battery box and mounts for starter relay and power circuit breaker. It's a mess in these pics from just getting wiring in place, follow with getting it all secured and neat.

There's no circuit anywhere that's not protected, including the main feeds from the battery itself. The only cable without a CB or fuse is the main starter cable as you would expect. But it's hot only when cranking.


The Grumpy Grease Monkey mechanical engineer.
Staff member
thank you gentlemen, its nice to see guys put some thought into the installation process, it looks impressive.


Well-Known Member
I appreciate that, thanks.

Here's yet another question - coolant with iron block/heads with aluminum radiator, and sealed overflow.

In past years I used the basic green coolant that worked ok. One weird thing I found at disassembly was inside the thermostat housing above the thermostat was a gooey mess of something that I think was a breakdown of the upper radiator hose. I'll find a picture of it. Below the thermostat (inside the intake) was fine, as was everywhere else, especially considering how long the car had just sat. There was some light corrosion right at the radiator cap but it was easily removed. I attributed it to a deteriorated seal at the cap.

I'm considering using Zerex G-05 coolant this time, or the equivalent O'Reilly/Prestone/Peak version (yellow) that are identified as "all makes and models, extended life". The key difference is that the basic green coolant contains phosphates and silicates, no nitrites. The yellow stuff has none of these components. I see where many older engines use the yellow without issue, as most these days use at least aluminum heads or radiators.

Lots of debate around dexcool, I've never had a problem with it in our truck, but then again I do regular maintenance. However, I don't think I need to use it in this engine.

Interested in your opinions, thanks. My thought is that if there's something better that's been developed since the first build I'd like to take advantage of it.


Staff member
The gooey mess you speak of is from silicates in the coolant.

Extended Life Coolants offer complete cooling system component protection and contain no silicates. They help to reduce water-pump failures, hard-water-scale deposits and silicate gel (the green goo you often see). They utilize organic additive technology and have the addition of nitrite and molybdate that protect cylinder liners from pitting corrosion damage. ELCs help reduce maintenance costs and improve water pump life, as well as eliminate the need for costly supplemental coolant additives.

Looks like the Nitrite Free is the one to use since it's better at protecting aluminum and heat transfer.

Nitrite Free ELCs are formulated to meet more severe operational conditions of modern, hotter-running engines. Nitrite free coolants provide improved protection of aluminum components including modern brazed aluminum heat exchangers and meet many of the latest OEM specifications. The versatile formulation may also be used in fleets that include passenger cars and light-duty trucks. The coolant is proven for extended life operation in medium and heavy-duty diesel, gasoline, LNG and natural gas vehicles and engines. (ELC NF) offers outstanding heat transfer that is superior to conventional coolants. The coolant has an extended life capability – up to 1,200,000 on-highway miles or 24,000 hours in Class 8 trucks1 and up to 600,000 miles or 12,000 hours in other commercial applications.


The Grumpy Grease Monkey mechanical engineer.
Staff member
any time you use aluminum heads on an iron block (ESPECIALLY WITH COPPER HEAD GASKETS )
but any head gasket on an iron block with aluminum heads, or an aluminum intake, or aluminum, water pump,
is going to have issues over time,
your forced to use ANODES and replace those ANODES regularly as they are designed to sacrificially corrode rather than the more expensive components, and replace the anti freeze at least every 12-18 months or the result you got is very common
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Great info , thank you! Looks like the "yellow" coolant is preferred.

Here's what I mentioned about the gunk I found inside the thermostat housing when I started engine teardown. My heart sank when I first saw it but this was the only place this happened, everywhere else was in good shape.

Inside the hose

Inside the intake and everywhere else was ok


Well-Known Member
Since this cam thread has blended into car build ;)......
Holley 850VS, electric choke rebuilt. I made a bracket for microswitch at the carb for th400 downshift control vs clunky overpriced aftermarket stuff.

Engine harness done and ready to install along the firewall and on the valve cover rails I made. It plugs in as shown for easier installation. I now use the braided mesh loom vs corrugated, IMO it's a cleaner look. I also use Tesa tape everywhere, cloth for inside and the high temp stuff for engine bay.20230527_121416_HDR_resized.jpg