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Discussion Starter · #1 ·
So the last time I changed my oil I found a few metal shavings; which is where this post starts, lol

I'm currently running a V3 FMIC Vortech pushing around 6 psi at 6000k on 93 pump gas.

I started calling around to see how much to stage 2 port the PI heads, and install a 300 ci stroker.

The shop is really big on not wanting to stroke the block because they said that invariably on a modular motor the piston travels too far down and the bottom of the piston smacks, making a racket and scoring the piston.

With that said,I know kits can be had that stroke out the block to 5.3L; so this doesn't sound right to me.

They suggested instead a 20-over with a stock stroke; which insanely is more expensive than the stroker assembly.

Hoping to get the extra compression down via the port work

Any thoughts are appreciated
 

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In order to get 5.3L you have to buy the new Boss 5.0 block with a 3.7" bore and stroke it out with the 5.0 stroker kit which still pulls the bottom of the piston out of the bore.

A 4.6L (281 ci) only has a 3.55" bore. The maximum that can be increased is .020" which doesn't really do a lot. It increases the 281 to around 283. The Boss 5.0 block is strictly aftermarket. It was never put into any car by the manufacturer. MMR sells them as an upgrade to their short block and long block product lines for $999.
Longblocks : Modular Motorsports, Home of the Worlds Fastest Modular Engines

You engine builder is correct in that the 5.0 stroker pulls the bottom of the piston out of the cylinder. That causes a small wobble increasing wear and tear. I don't remember reading about the increased noise before. A lot of people have run a 5.0 stroker. It was a popular mod back where there were few other choices. I have no idea how many miles they got out of them. A lot of the former forum members only ran their built cars a few thousand miles per year.

With the release of the Coyote motor a different stroker kit started being sold. It created a 4.75L motor and it did not have the drawbacks of the 5.0 stroker.

The 5.0 stroker has the same big disadvantage of the 4.6. The 3.55" cylinder is so small that the valves are partially shrouded. I have recently read that Ford decided on that size for front wheel drive cars where the motor sits in the engine bay sideways. The Boss block with its 5.7" bore (same as the Coyote) is the same size but made differently. But the Boss block is heavy. It adds weight to the front of the car. Trickflow heads also solve the valve problem without the additional weight.

MMR still sells 5.0L stroker short blocks and long blocks. A lot of people have a love affair with the 5.0 and it is one way to have one. But that love affair was to the old push rod motor and there is nothing magical about that size motor. To me that motor is nothing but little 302 ci motor. Back in the 60s and 70s I drove 426s and 440s. A stroked out 289 (the 302) was still a small motor. I had a couple of F-150 pickups with a 300 ci (4.9L) inline six cylinder motor. That was a strong little motor.

I now drive a 281 ci (4.6L) Mustang. The only smaller V8 I remember was the Chevy 265. But it had a 3.75" bore with a short stroke and it later became a 283 and a 302. The only way to get power out of little motors is with power adders (nitrous, superchargers, or turbochargers). With the supercharger my little 281 turns in about the same times as that old 1966 Dodge with its massive 440 motor.

I guess what I'm trying to say is the 5.0 stroker does have some problems but I don't believe they are show stoppers if that is what you really want. It just that there is nothing special about having a 5.0L motor. There are lots of ways to make horsepower.
 

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An aluminum block can most defiantly be bored over .020.
The 4.75 stroker has been know to sometimes turn to ****!
The aluminum blocks can be sleeved with larger bore cylinders.
Some guys have went .070 over in race cars.
 

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An aluminum block can most defiantly be bored over .020.
The 4.75 stroker has been know to sometimes turn to ****!
The aluminum blocks can be sleeved with larger bore cylinders.
Some guys have went .070 over in race cars.
All it takes is money and the OP was complaining about boring .020" over as being "insanely more expensive." That is why I posted the cost of the Boss 5.0 block. I'm sure he would think the extra $999 as also insanely more expensive.
 

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OP needs to buy a stock cobra crankshaft they are cheaper than the coyote "4.75" crankshaft. The shop is correct.
 

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The 4.75 stroker is a good motor Its critical to get the thrust bearing clearances correct and run that spacer between the flexplate and engine. I know myself and Nitmare have both been running the stroker for many years. Part of the game when your running alot of boost or a hot rod setup is major melt downs it happens to all of us, NASCAR, NHRA ETC. I have had my share of issues as all of us who go after the GOLD do its part of the game..

I got a set of stroker pistons setting on the shelf in the garage with a couple years on them and the skirts do not look bad as some claim. It must boil down to the assembly.

My suggestion is either school up your shop or find another one.
 

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hey, I am building my 4.75 right now. I have a question about the thrust bearing. are you willing to take a phone call? thanks man
 

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hey, I am building my 4.75 right now. I have a question about the thrust bearing. are you willing to take a phone call? thanks man
PM me...
 

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Discussion Starter · #9 ·
Thank You

Thank you so much for the advice everyone! I think I'm going to either just forge out the lower to a stock stroke and up the boost. I could grab a FRP 5.3 stroker SB from work at a discount; so if I am deadset on a stroker I'll go in that direction; but I honestly have the power-adder already; so maybe I should just take advantage of it (might be my biggest bang for the buck).

Thanks again everyone!
 

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My setup is making over 600hp with 10psi. I have stock stroke and almost stock bore.
 
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