Engine opinions on Probe 521 build

Hi guys, haven't been on the site in some time but looking to the experts for some guidance. First off I have a 1971 Ford Torino that I am building an engine for. I started a couple years ago with a pretty stout 466 build with a solid lifter camshaft. Upon break in I noticed the oil pressure drop a little low for my liking, it was around 15-20 psi hot. Not too bad but expected more. As I drove it more the pressure never got better and at idle in drive when hot it would read a little less than 10 psi, just enough to make the oil light flicker. This winter I tore the engine down to investigate and found the number 2,3,4 main bearings were about ruined. It is an external balance engine and everything was balanced prior to assembly, and all bearing clearances were within spec (from my memory, can't remember the nubers at the moment). I had run it less than 1500 miles.

Here is my dilemma. A good friend is a dealer for Probe and said he can get me a complete 521 kit. Forged crankshaft, forged pistons, good rods, I believe rings and bearings, all banced. The price is not too bad either. I feel somewhat bad not using my current parts since they have little to no wear on them but there is no replacement for displacement. Cost aside (I am never getting rid of this car and want to enjoy it as much as I can) what would you guys do?

I want to keep some of the parts I already have. Block obviously, heads and intake. Everything else is up for discussion. I have the Blue Thunder heads (have to measure the combustion chamber cc's) with the stock port locations, CJ style ports. I also have the Blue Thunder high rise dual plane intake. I want to keep these parts to keep things looking sort of stock under the hood. It's mostly a street car, maybe a handful of passes at the track each year. I am also running Hooker 6115 headers, they have 1 7/8" primaries and am running dual 3" exhaust, probably through a pair of Dynomax mufflers.

The heads... Should I look into getting them ported and cleaned up? I was also wondering if the intake should be cleaned up as well? Is this even done, and would I see any real benefit? I am not going overboard but want what I have to be able to comfortably support the extra displacement.

Camshaft... I don't mind making periodic valve lash adjustments, always a good time to inspect everything under the valve covers. I like the idea of another solid lifter cam, I was really happy with what I had. It was custom ground for the 466 but I think I would need to look into something else for a 521. Stick with a hydraulic lifter cam, or even look into a hydraulic roller cam?

Carburetor... I had a Holley 830 with annular boosters and other than being a pin to start when the weather was cold it ran really well. Still needed some tuning but the engine is apart now I was thinking a 950 or even saw a 1000 browsing through one of my catalogs the other day. Double pumper carb. Do I need a downleg booster carb or should I stick with the annular booster?

Sorry for som much at once but I'm getting close to putting primer on the car before paint and need to get an idea of what to do so I can get the engine built and installed after I get the rest of the car done. As always thanks so much for the help and any ideas comments or criticisms

-Jesse

So what actually caused the problem, or did I miss it? I would have somebody who really knows BBF's build a completely different short block and use your heads and intake after you are sure they are OK.

The machine shop guy thought that there was something blocking one of the passages or had blocked it at some point, thought it was the thread sealant I had used on the oil gallery plugs. Block checked out good all the way around, it was line bored as well the first time around and checked out the second time. We also checked the crankshaft and it was straight. Could have possibly been a bad surface on the main journals from being machined the first time bug I really doubt that. I figured that I did not do a meticulous enough job cleaning the oil passages in the crank itself, that's what I think really happened

Absolutely no negatives to 500+ cubes You already have good heads and intake etc to work nicely with the 521 . Stick with the solid cam . What specs is the one you have now . may work with more cubes ??

Gregaust wrote:Absolutely no negatives to 500+ cubes You already have good heads and intake etc to work nicely with the 521 . Stick with the solid cam . What specs is the one you have now . may work with more cubes ??

NO negatives ... until you get on a highway and put gasoline in it.

If it is not a regular street driven vehicle then it probably doesn't matter.

I'm a huge fan of hydraulic roller in street, and street and strip applications....and are the heads Ford or Chevy exhaust port?

Mark O'Neal wrote:I'm a huge fan of hydraulic roller in street, and street and strip applications....and are the heads Ford or Chevy exhaust port?

I won't go into specifics however, in 1986, Ford Motor Company; Truck Division spent a year testing and evaluating using a hydraulic roller valve train in 385 series engines for their upcoming F.I. engines.
For weighing durability and performance reasoning, they chose NOT to go that route. Prospective warantee claims had a lot to do with it.

I noted you mentioned that. I can only go on my experience in using them, which has resulted in no warantee issues, or problems even...at least in street cars. I have no idea if anything has changed since 1986, or if that was actually the issue. Knowing Ford it could have been the expense vs the comparatively low volume of 460s produced. Notably they didn't stuck on in a 351W until 92 or 93 either.

Mark O'Neal wrote:I noted you mentioned that. I can only go on my experience in using them, which has resulted in no warantee issues, or problems even...at least in street cars. I have no idea if anything has changed since 1986, or if that was actually the issue. Knowing Ford it could have been the expense vs the comparatively low volume of 460s produced. Notably they didn't stuck on in a 351W until 92 or 93 either.

It's a geometry issue specific to the 385 series. Randy knows the deal, and I'm talking out my butt.

cletus66 wrote:

It's a geometry issue specific to the 385 series. Randy knows the deal, and I'm talking out my butt.

Talking out my butt as well anyone that has been on the site awhile knows the general feelings towards hyd roller lifters. The part I never understood is others like Mark don't seem to have a problem with these "geometry" issues. I know almost every build I have seen Kaase post has had hyd rollers in it too.

jasonf wrote:

cletus66 wrote:

It's a geometry issue specific to the 385 series. Randy knows the deal, and I'm talking out my butt.

Talking out my butt as well anyone that has been on the site awhile knows the general feelings towards hyd lifters. The part I never understood is others like Mark don't seem to have a problem with these "geometry" issues. I know almost every build I have seen Kaase post has had hyd rollers in it too.

Then use hydraulic roller lifters in a 385 engine if you wish. Without needing to stand behind a 60,000 mile warranty they may be just fine for you ... a Boss Hemi doesn't share the same issues.

"When 40,000 people believe in a dumb idea ... it is still a dumb idea", Ben Franklin.

I doubt most of the engines in question even see a few thousand miles a year.

cletus66 wrote:

Mark O'Neal wrote:I noted you mentioned that. I can only go on my experience in using them, which has resulted in no warantee issues, or problems even...at least in street cars. I have no idea if anything has changed since 1986, or if that was actually the issue. Knowing Ford it could have been the expense vs the comparatively low volume of 460s produced. Notably they didn't stuck on in a 351W until 92 or 93 either.

It's a geometry issue specific to the 385 series. Randy knows the deal, and I'm talking out my butt.

I'm researching it. Prior to Randy mentioning it, I had never heard it....always up to learn something.

I would have thought that a BBC had worse push rod angles than a BBF. Maybe its the combination of push rods and rocker angles.

BBC don't have all the lifter bores inline

IDT-572 wrote:I would have thought that a BBC had worse push rod angles than a BBF. Maybe its the combination of push rods and rocker angles.

Well, in a Big Block Chevy block, the lifters are NOT in the same plane, exhaust to intake. Their angularity with the pushrod is not as much and a production Chevrolet rocker uses a ball fulcrum, (not a sled), so the rocker arm is free to tilt and twist in whatever direction it needs to go.

In a big block Chevrolet the hydraulic roller lifters can do an ADEQUATE job in order to make the needed warranty mileage.

Matter of fact, Ford and Chevrolet were doing that endurance testing at the same time in the 80's and each came to a different conclusion for their particular engine.

Then use hydraulic roller lifters in a 385 engine if you wish. Without needing to stand behind a 60,000 mile warranty they may be just fine for you

Well it was a question and by stating I was "talking out my butt" I thought it was pretty clear I am not an expert on the subject. I guess the scratch your head confused smiley threw you off.

a Boss Hemi doesn't share the same issues.

I was wondering about that but did not ask. Thank you for clarifying it though.

Does the hydraulic roller lifter have a higher pushrod seat height? I've always wondered why the hyd roller would be different than a solid roller (cam profile aside).

Chris

Injected65 wrote:Does the hydraulic roller lifter have a higher pushrod seat height? I've always wondered why the hyd roller would be different than a solid roller (cam profile aside).

Chris

I've never used one but i believe yes it does . That's what throws the geometry off