Accufab 4.6L - 5.4L Racing Engines

Accufab 4.6L - 5.4L Racing Engines


Accufab 4.6L Engine

One man has dedicated 20-plus years of his life to expanding on what Ford started after introducing this overhead cam V8, and that’s John Mihovetz; owner and operator of Accufab Racing. His 2008 Pro Mod Mustang holds the world record for being the quickest and fastest Modular motor ever, with an outstanding 5.88 E.T. at over 250 mph.


During the last 20 years, Mihovetz has been the man behind a majority of every single modular record in the 1/4-mile. Being the first in the 8-,7-,6, and 5-second zones with a modular engine. His portfolio of achievements with this engine platform is quite a lengthy one, which alone makes him the ‘mod motor authority.’ Mihovetz is the ideal candidate to rifle through the common misconceptions that surround this highly potent engine platform.


When it comes to modular engines, it’s not the iron block that reigns supreme in regards to making significant power. The aluminum factory ‘Teksid’ 4.6 and ‘Cobra Jet’ 5.4 blocks are the pinnacles of horsepower potential. This potential is completely head-to-head in terms of performance, with both factory blocks providing exponential promise in the 1/8-mile to standing-mile competition. Instead of following the thought process that one engine is better than the other, we asked about the misconceptions of comparing the two powerplants.


“That’s a general misconception,” Mihovetz said in regards to iron blocks being stronger than aluminum ones. “Ideally, it depends on strength, and what you’re doing. Certainly, the iron block is a pretty decent piece up to a point, and if you’re below that point it works fine. If strength is required beyond, by far the Teksid block is the best piece — specifically the 4.6 4-valve engines.”


Accufab 4.6L Engine

Mihovetz continued his thoughts on the comparison. “It’s the same issue with the 5.4 block. The biggest negative thing about the iron block is that the cylinders are too thin on an untouched block. If you sonic-check the thickness, you would find that it’s between .120- to .125-inch, so it’s just too thin,” He said. “And, of course, everyone thinks bigger is better, so they bore it .030 over and thin the cylinder wall out even more.”


“With that being said, as soon as you make decent power the block ends up splitting. Where the aluminum block has an advantage, specifically, is in the case of the cylinder liner,” Mihovetz explained. “A typical sleeve is 90-thousandths thick in its stock form, and then you have anywhere from a 1/4- to 3/8-inch added wall thickness of aluminum to back it up. This added material helps keep the cylinders round.”


According to Mihovetz, as cylinder pressure builds in both the 5.4 and 4.6 iron blocks, the issue of cylinder sleeves only being supported top and bottom becomes a consideration. This shortfall reduces the potential of the block and does not allow for a reliable base to make a massive amount of power.


We don't just build it, we race it.
Over 20 years of race proven Ford Mod Motor development.

Our 4.6L and 5.4L Ford mod motors are the fastest mod motors in the world.


What we do:

Build serious 4.6L and 5.4L Ford Mod Motor engines.
Strip or Street.
Specialize in Turbo and Supercharged applications.
Motec Engine Tuning.
Turn Key Cars.


We don't make excuses or false promises!


For additional technical information click here.


Please contact John Mihovetz directly by calling 909-930-1751.




4.6L - 5.4L Engine Component - Parts


Did you know Accufab offers custom ordering for many well known racing brands?

We have the BEST connections in the industry to meet all of your engine building needs.


ARP Fasteners & Bolts

Autolite Spark Plugs

Bryant Racing Crankshafts… starting from $4500 balanced

Clark Head Gaskets

Clevite Rod Bearings

Comp Cams Camshafts… starting from $1500 custom order

Dailey Engineering Dry Sump Oil Pumps… starting from $3500

Federal Mogul Speed Pro Main Bearings

Ford Racing Blocks

Hogans Racing Manifolds… starting from $3600

JE Pistons… starting from $1400 custom order

Lenco Transmissions… starting from $8000

Lucas Oil Engine Assembly Products

Manley Connecting Rods, Valves & Springs

PAC Valve Springs

Total Seal Rings

Trend Performance Wrist Pins


Within three business days, expert specs will be given to you personally by John Mihovetz, NHRA Record Holder & NHRA Engineering Award recipient.


Please contact us at this link, or call Accufab (909 930-1751), and we’ll get you the quote you need.
Please include: as many specifications, and as much information as possible.


Please follow this link for additional Ford Mod Motor Parts manufactured by Accufab.




Accufab's Mod Motor Records:


World's Fastest Mod Motor - First Mod Motor Into 8's, 7's, 6's, 5's - First + 200, 210, 220, 230, 240; 250 Mph - World's Fastest Ford Lightning - Fastest Screw Supercharged Lightning - Fastest Screw Shelby - Fastest Turbo Mustang - Fastest Ford GT 1/2 and 1 Mile - Two Standing Mile World Records - PSCA Pro Street Champion - Eight PSCA Pro Street Wins - Seven Time NHRA Record Holder