My Cam Research for the Experts Eye

TXChevy

Well-Known Member
ITS always nice to see the ideas when you build custom built tools
Thanks Grumpy, I'm motivated by your help and comments. The links and Ricks build thread are great info.
Besides, where possible I'd rather make a tool and put the saved dollars into good parts!
 

Indycars

Administrator
Staff member
General color scheme will be gloss black for block and heads, gloss gray for oil pan, brackets, mounts, gray headers and aluminum intake and timing cover.
Those colors would make for a very clean looking setup !

That looks like a Ford 9" or is it a 8.8" rear axle ? What lube/friction modifier are you going to use ?

Did you bend your own brake lines ?
 

TXChevy

Well-Known Member
Hi Rick,
- Ford 9 in trac-lok , 3:70 gearing, Moser 28s axles
- in these I prefer a good quality 75-90 with the Ford friction modifier. I had first installed it in 1990, gears and pattern looked perfect when I opened it up to replace gaskets and pinion seal. It uses a solid spacer so reassembly was easy.
- I bend/flare all my own fuel and brake lines

Very interesting info from Felpro tech conversation....
As I had mentioned I've got 2 rear main seals here:
- 2904, silicone
- BS400961, rubber
I also asked about the 2918 viton seal.

The gentleman I talked with was very knowledgeable. He said that since 2018 approx, the 2904 and BS400961 are the same formulation, which is blended silicone/rubber. So if you get one or the other you're actually buying the same seal. Looking at them, they both look the same but that's just eyeballing them, not determining their composition. I wasn't really sure in this case why one of the part numbers hasn't been dropped. He didn't say it but I wondered if its a marketing decision.
The viton is an upgrade more suited to higher hp, higher psi oil pressure, boosted, turbo, etc with higher crankcase pressures. He didn't really recommend it for my application and said that either of the 2 seals I already have would work fine. He also said the installation error, poor crank surface were the primary causes of failure, and said to offset it when installing, including a light sealant behind it and at the mating ends.
I had mentioned the old seal was a National 5702, I think it was, which is a rubber formulation seal. No problems with it.

So essentially the choice is the silicone/rubber blend or the viton. I'm going to install the BS400961 seal that I already have per recommended guidelines.
 

TXChevy

Well-Known Member
Incidentally, this is the deck surface after going over with 600 grit and cleaned with acetone. Shop had pronounced it flat and I thought it was ok to simply give it a going over without going overboard on sanding, or with more aggressive grit. I'm not worried about the staining, just the cleanliness of the surface. I'm planning to use FP Permatorque head gaskets, they worked excellent on the prior build. I'll get into final thickness and bore diameter as I get closer to head installation, and after I verify deck height. All threads are chased and coolant passages deburred.
Am I overlooking anything? Thanks

20220106_131151_HDR_resized.jpg
 

Indycars

Administrator
Staff member
- Ford 9 in trac-lok , 3:70 gearing, Moser 28s axles
- in these I prefer a good quality 75-90 with the Ford friction modifier.
I have the same here, except I think it's a 3.88 ratio. I bought Amoil 75w90 and their Slip Lock friction modifier. I always thought I had a 3.7 ratio, but I see the numbers 935 on the ring gear now that I have it open.

I'm probably the only one that worries about when the rings going in and where they meet that edge created by the cylinder and deck. If you look at it under magnification, it looks like it could leave some fairly good scratches in the rings. So that's why I polished that edge before installing the rings.

Otherwise I think you have it under complete control !
 

TXChevy

Well-Known Member
I'm probably the only one that worries about when the rings going in and where they meet that edge created by the cylinder and deck. If you look at it under magnification, it looks like it could leave some fairly good scratches in the rings. So that's why I polished that edge before installing the rings.
I agree with you. I had taken a light sanding drum at 45 degree angle to ensure that top edge had a chamfer. I may go back and polish that edge a bit more.
I've got the scissor type ring compressor but decided to get the summit adjustable compressor as it seems simpler and dependable:

You may want to double check your ratio by giving one axle a complete revolution and counting how many times the driveshaft turns. I think you may have a 3:73.
 

Indycars

Administrator
Staff member
I used a Unitized Wheel like below on a die grinder to polish the edge.

www.amazon.com/Scotch-Brite-Unitized-Aluminum-Diameter-Coarse/dp/B008S30U06/ref=zg_bs_256203011_16/146-5171026-4147967?pd_rd_i=B06ZXX6SMJ&th=1
1641679051781.png

I did that way back and thought I had a 3.7 ratio, but I have the 3rd member out right now. Below are all the alpha numeric characters on the ring gear. The only ones that made sense to me was the 935 ...... 35/9 = 3.88. I didn't think that 3.88 was that common.

What do you think ?

FP01_RingGearNumbers_03121.jpg
FP01_RingGearNumbers_03122.jpg
 

TXChevy

Well-Known Member
I'll try to look up some info but off the top of my head I'm not sure about the 3.88, it's not a ratio I've heard of. But yes, I see how you're getting that number.
I'm still leaning to 3.73 or 3.93 though.
It looks like you have the pumpkin out but the r & p are still assembled? Even with it out, you should still be able to mark the ring gear, turn it 1 rev, and count turns of the yoke.
 

Indycars

Administrator
Staff member
So I don't hi-jack your thread, I will start my own in the next few days. I have some extraordinary plans for this winter project.

BTW, I have Moser axles also ! I have a great story of when my right axle came out going into a left hand turn ???
 

TXChevy

Well-Known Member
Another scraptastic tool....
Rotating assembly has been balanced in prior build so "theoretically" the only new weight difference might be from the change to new scat rods.
I put this holder together to hold the piston/rod assembly the same way each time to verify weights. If something's way off I'll take a bit off accordingly.
The main thing to me was to have checking repeatability for each assembly.
20220112_110810_HDR_resized.jpg20220112_111555_HDR_resized.jpg20220112_111630_HDR_resized.jpg

Edit....I was able to successfully compare weights - all the piston ends were within 1 gram so I left them alone. The rod ends were within a couple of grams, except for a couple that were slightly over that. I carefully took a bit off the end pad to get these to within a couple of grams of the others. For my skillset and available measuring tools this was close enough for me.
 

TXChevy

Well-Known Member
Stop right there, I love the color
Lol I liked it too! Its just a self-etching primer but its a pretty cool color.

My cam and valve train stuff should be ready in about a week but I asked if they could hold shipping till last week of Jan. We're taking an RV trip to Ft. Davis, TX and I didn't want $2k worth of parts sitting on the porch. Straub is very responsive and accommodating to questions and requests like this one.
 

TXChevy

Well-Known Member
Block is now painted :)
It will sit like this for a week or so, then I'll start assembly of the shortblock. Rick I'll remember to check rotational torque at intervals like you did.
20220114_133720_HDR_resized.jpg20220114_133734_HDR_resized.jpg
I'm expecting cam and valvetrain to be ready to ship by the time we're back home, so cylinder heads can go in for work.
In the meantime I'm also going back into electrical for cranking, HEI, and temporary gauges for first start. I had a trunk mounted battery that I'll repeat but with improvements. Fuel system is done and I'll set the radiator in place for cooling.
So for sequencing, as I get the engine done, I'm finishing "utility support" just to get it running. When that phase is done I'll rebuild the th400 and install it. Brakes, axle are also done so that will be first drive.
Then I'll finish body electrical, dash, trunk, radio etc. Very last thing will be interior upholstery in a driving vehicle.
 

Grumpy

The Grumpy Grease Monkey mechanical engineer.
Staff member









 

TXChevy

Well-Known Member
Dang, I thought this was just an engine build. But it's just short of a frame off restoration !
Lol yes. Pretty much everything gets refurbished.
But it's a good time for me to remember the basis of this thread which is basically engine, especially valvetrain. I'll be focusing back on that topic in the weeks ahead as I re-assemble
:thumbsup:
 

Indycars

Administrator
Staff member
Have you thought about coating your piston tops, combustion chambers and valves ?

Cerakote has three coatings that can be sprayed at home, although they do require blasting to obtain good adhesion. One of them is Air Cured. Maybe you have a blaster ? Spray gun with a 0.8 tip ?

You could also take the Cerakote to your automotive paint store and have them put it in a rattle can.


 
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