427 with 4.280 pistons?

[Dumpling]

Is it out of the question to have different bore sizes in the same engine?  +.050 in some cylinders, +.030 in others?

[blykins]

Out of the question?  The high-quantity rebuilders (Jasper, etc.) used to do it all the time to save money. 

Is it the right way of doing things?  No....

[KMcCullah]

Well, the block now has 8 new sleeves, with JE, 4.25, 12.5 to 1 Pistons on order and a set of Trick flow heads.

Nick

I think I'd Hard Blok it to the water pump holes, just to firm things up. And maybe add an oil cooler if it's gonna be running down the highway. Sounds like a sweet F100!

[NIsaacs]

I can't post a picture, but I can post a link to one, Lol. This is what it looked like in the mid '80's, racing at Phoenix Raceway Park.

https://www.turbodieselregister.com/threads/259571-To-scratch-an-itch-caused-by-an-elephant?p=2521681#post2521681

Nick

[Dumpling]

Out of the question?  The high-quantity rebuilders (Jasper, etc.) used to do it all the time to save money. 

Is it the right way of doing things?  No....

Why not?
If the off-sized cylinders are matched around some point of symetry?

[blykins]

It's rarely done that way....it's always to fix a boogered-up cylinder or something. 

But, if you were to just randomly bump the bore size up on certain cylinders, you're gonna have higher compression ratio and even hp/torque on those cylinders.  It's never gonna be balanced.  Not sure why you'd want to do that on purpose.

[cjshaker]

Out of the question?  The high-quantity rebuilders (Jasper, etc.) used to do it all the time to save money. 

I had to read that twice. At first I thought you said quality, not quantity

I've never seen it done, but I'd imagine it would be impossible to balance an engine built that way. The difference in power output per cylinder would only exaggerate that feeling. Puts me in mind of a dryer in the spin cycle.

[C6AE]

Is it out of the question to have different bore sizes in the same engine?  +.050 in some cylinders, +.030 in others?

 I have seen this, more than once it was a surprise, and if you didn't know it was done you probably would never know. Replacement OEM pistons are all the same weight and the difference in displacement is too minimal to "feel" a difference.  There were set-ups to bore engines as well as turn crankshafts while the block was in the car. I have also seen odd sized rod journals, rods of significantly different length, and many other examples of pragmatism. I have seen plenty of heavy diesels with odd pistons, different compression ratios even. The owner or driver never had a clue...

[bsprowl]

I've done it a couple of times when a cylinder would not clean up at 0.030.  It cleaned up at 0.040 or 0.060 (that let me use an off the shelf piston and ring set).  I removed a enough metal in the combustion chamber to even out the compression ratio (the first time) and even made it a bit less (the second with the 0.060 piston) to compensate for the power produced by the slightly larger cylinder displacement.

The engines ran fine.  No noticeable vibration.  Both times the owners were aware of what I was doing and the cost of fixing right and fixing this away was the reason for the "poor boy" fix.  I'd do it again.

[NIsaacs]

Starting to look like an FE again. I think those rockers are Speedmaster. Are they any good? Crane solid roller can, no clue on the lifters.

[NIsaacs]

I could only post one attachment for some reason, here is the cam card.

Humm, for some reason I can't post it. Here is a link instead: https://www.summitracing.com/parts/crn-348521/overview/make/ford
 Here is the truck, maybe, lol

[NIsaacs]

About 1985 I think...

[turbohunter]

Starting to look like an FE again. I think those rockers are Speedmaster. Are they any good? Crane solid roller can, no clue on the lifters.

Think those rockers are PRW. They’re stainless. I’ve been running a set in my truck for years on a hydraulic roller with no problems.

[thatdarncat]

Starting to look like an FE again. I think those rockers are Speedmaster. Are they any good? Crane solid roller can, no clue on the lifters.

The subject of that style rocker arm came up recently on the FE Fanatics Facebook page, there were warnings of failures. I don’t know all the details, but you may want to investigate further before using. I don’t know if the rockers in these pictures are exactly the same, but the owner of at least one said it was a PRW.

[blykins]

I would also check the rocker arm pattern as well.   Rocker stands need a big cut off the bottoms to work with Trick Flow heads.