351c Build Ideas And Advice

[Q1SVT]

... Food for THOUGHT ...

Hank the Crank was thought to be the person that 'created the myth of Cleveland oil issues'
https://www.tapatalk.com/groups/clevelands/hank-the-crank-oil-mods-t15465.html
Wanye Gapp is who's who... Roush was just a cling-on
Gapp was a FORD engineer on the SOHC 427, then the NASCAR 429 & BOSS, then involved in the Nascar 366 rules - possible changes [ aka Boss 302 4V heads] Then the key in the Gapp & Rosch drag racing history...

none of the BS is needed on Clevelands, unless you are turning very high RPM's...

Why did people use an oil restrictor in the Mains flowing into the Cam passage?
With RACE CAM profiles of the day, required Valve Spring rates off the graph pressures to keep the lifters in contact with the cam lobes.

WITH those pressures coming from both left and right side of the block it would create egging shape of wear to the lower side of the cam bearings.
Cam Shafts flex under higher RPM's... causing the cam races to lift off of the lower egged out bearings... blowing off ALL OIL pressure of that main. Often causing the damage to the main bearings, rotation, scaring, etc

I have owned 351C's since 1971, and have never applied any of the OIL BS, except I routinely use .040 oil restricted push rods.

 

[70cobrascj]

... Food for THOUGHT ...

Hank the Crank was thought to be the person that 'created the myth of Cleveland oil issues'
https://www.tapatalk.com/groups/clevelands/hank-the-crank-oil-mods-t15465.html
Wanye Gapp is who's who... Roush was just a cling-on
Gapp was a FORD engineer on the SOHC 427, then the NASCAR 429 & BOSS, then involved in the Nascar 366 rules - possible changes [ aka Boss 302 4V heads] Then the key in the Gapp & Rosch drag racing history...

none of the BS is needed on Clevelands, unless you are turning very high RPM's...

Why did people use an oil restrictor in the Mains flowing into the Cam passage?
With RACE CAM profiles of the day, required Valve Spring rates off the graph pressures to keep the lifters in contact with the cam lobes.

WITH those pressures coming from both left and right side of the block it would create egging shape of wear to the lower side of the cam bearings.
Cam Shafts flex under higher RPM's... causing the cam races to lift off of the lower egged out bearings... blowing off ALL OIL pressure of that main. Often causing the damage to the main bearings, rotation, scaring, etc

I have owned 351C's since 1971, and have never applied any of the OIL BS, except I routinely use .040 oil restricted push rods.

The shop I had my motor done at said bushing the lifters wasn’t needed and to restrict oil with the pushrod. Also said something about the clocking of the oil passages in the crank contributing to some of the issue but with aftermarket stoker cranks it wasn’t a problem.

 

[Zach]

Not going to pretend I know everything cause I don't, this engine is more than 30 years older than me and I have only been researching a Cleveland for the past year or so, my knowledge is very minimal around them. Following TMeyers suggestion he sells grooved cam bearings that are meant to be clocked to change the flow of the oil, also purchased the "performance" version which is just a harder material made for high spring pressure. With these cam bearings he recommends tapping the larger hole in the front main saddle and drilling out the smaller hole a little bigger. In his oil simulations the front of the crank is drowning in oil, which is his justification on limiting the oil. DragBoss does a better explanation and diagram than I can type. Judging by how worn my crank, piston bores, timing chain, etc, my engine has a lot of miles on it and was not gonna run much longer in its current state. I can guarantee my lifter bores are far from perfect, so having a brand new sleeve wouldn't hurt in my eyes. I am not planning on running my engine 7k+ constantly but with the internals I am putting into it I have the ability to do so, so why not make sure the oiling system is as efficient as it can be. The engine build I am doing is far from a stock/factory rebuild with a few hop ups. Just my justification for all the work from what I have read, I have no hands on experience with a 351c so hearing things like this is helpful no matter the context.

 

[Q1SVT]

My prior post has a link.. it was HTC crankshafts with issues.

Ford OEM 351C crankshafts are timed to the rods, the big ends are oil squirters for piston pin oiling, general cooling and oiling cylinder walls.

There is a grove along the parting line of the caps, bearings have cutouts to create a passage. funny no one says to increase main oil pressure to block them passages lol

 

[Q1SVT]

Not going to pretend I know everything cause I don't, this engine is more than 30 years older than me and I have only been researching a Cleveland for the past year or so, my knowledge is very minimal around them.

The key is you are trying to learn...

One of the best books. Author is from down under but he actually spent time in Dearborn Michigan and got access to the Ford Motor Co. Libraries
He comes closet to the real history of the 351C.