Whats so hard about building a mod motor?
Whats so hard about building a mod motor?
Just wondering, whats so hard about building a mod motor. Aside from the OHC and chain/cam drive, whats really different than building a standard pushrod V8? I can understand a quicker block expansion rate with the alumn cobra block, but thats not an issue for us.
Everyone says to find a builder experienced with mod motors, why? Why couldn't someone experienced with pushrod motors build a modular? Please respond tuners, beacuse i've heard this myth for a while and think its just that....a myth. Exactly what is different with the build (besides the obvious OHC). I've got the 'parts on the bench' so to speak, so I'll be starting the buildup very soon.
Thanks for the info.
Everyone says to find a builder experienced with mod motors, why? Why couldn't someone experienced with pushrod motors build a modular? Please respond tuners, beacuse i've heard this myth for a while and think its just that....a myth. Exactly what is different with the build (besides the obvious OHC). I've got the 'parts on the bench' so to speak, so I'll be starting the buildup very soon.
Thanks for the info.
Originally posted by Rob_02Lightning
Great Question rscoleman
Lets wait to hear the answer, but I've also ALWAYS heard the builder MUST BE familiar with Mod motors to get it right ???
Great Question rscoleman
Lets wait to hear the answer, but I've also ALWAYS heard the builder MUST BE familiar with Mod motors to get it right ???
The major reason being that their is a torque sequence on the crank that MUST be followed and the thrust is a 3 piece design instead of a one piece insert.Really if you follow the book it is not any harder than any other motor.BUT you MUST follow the book.Otherwise you can crack the block or atleast warp the main brg. centerline.Stan
Stan is correct. I lost a mod motor early in 97 because the engine builder thought a mod motor could be built the same way. Mod motors have a lot of tight tolerances and at the time, a lot of the engine builders werent familiar with the procedures per Ford for assembly.
The AERA has extensive publications available to it's members. Most reputable shops belong. Ask you builder or parts supplier.
I spoke to them (my ex biz, BHJ Products, was a member). They faxed me 76 pages of detailed disassembly and assembly procedures. Great stuff, It's all there.
I spoke to them (my ex biz, BHJ Products, was a member). They faxed me 76 pages of detailed disassembly and assembly procedures. Great stuff, It's all there.
modular motor tolerances are much tighter than say your average 302 ford or 350 chevy (either of which you can pretty much slap together with a cresent wrench and a butter knife and make run for a decent amount of time).
mod motor specs are in metric, which is FAR more accurate. many shops don't even have any metric measuring equipment. conversion can be very confusing and also reduces accuracy.
mod motors use LOTS of thin torque to yield bolts (stretch, one use only). torque to yeild bolts have torque steps and you have to do multiple steps in degrees, not just one simple ft/lb torquing.
you can't prime an oil pump on a mod motor (very easily).
at least twice as many timing chains and thus more chance for valves to bend/break if you get the timing slightly off.
bolting a mod motor together isn't hard, it IS however more complicated than your average pushrod v8, and there is a difference between just "bolting a motor together" versus actually measuring and checking and setting all of the tolerances correctly and doing it right.
later,
chris
mod motor specs are in metric, which is FAR more accurate. many shops don't even have any metric measuring equipment. conversion can be very confusing and also reduces accuracy.
mod motors use LOTS of thin torque to yield bolts (stretch, one use only). torque to yeild bolts have torque steps and you have to do multiple steps in degrees, not just one simple ft/lb torquing.
you can't prime an oil pump on a mod motor (very easily).
at least twice as many timing chains and thus more chance for valves to bend/break if you get the timing slightly off.
bolting a mod motor together isn't hard, it IS however more complicated than your average pushrod v8, and there is a difference between just "bolting a motor together" versus actually measuring and checking and setting all of the tolerances correctly and doing it right.
later,
chris
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The first motor I have ever built was this one.
Buy the CD online (I got mine from ebay)
the tricky part, besides the timing, is the boring. This must be done with a torque plate.
If your using the stock bore, no problems.
I found the cd invaluable for torque specs and sequencing.
I have had no problems with my engine.
good luck!
PS-be sure to switch all critical fasteners to ARP!
-Andy
Buy the CD online (I got mine from ebay)
the tricky part, besides the timing, is the boring. This must be done with a torque plate.
If your using the stock bore, no problems.
I found the cd invaluable for torque specs and sequencing.
I have had no problems with my engine.
good luck!
PS-be sure to switch all critical fasteners to ARP!
-Andy
Last edited by teamSLS; Jul 21, 2003 at 01:13 PM.
Building a mod motor is a walk in the park compared to building, say, a Testarossa 48 valve flat 12, or even a basic 3 liter (250) V-12.
I've built five of these puppies and assembly is like a "one time" jigsaw puzzle, put one piece on in the wrong sequence and five pieces later, ya gotta go back and start over, plus there ain't no Ferrari CD.
Hence my moniker.
BTW, metric tolerances aren't tighter, it's just that the normally used, smallest increment is .01mm which is approx. .0004". It just seems that way. The truth of the matter is, yes these engines certainly are built to tighter tolerances but nothing closer than I've seen in forty years of drag racing and then restoring Ferraris.
I've built five of these puppies and assembly is like a "one time" jigsaw puzzle, put one piece on in the wrong sequence and five pieces later, ya gotta go back and start over, plus there ain't no Ferrari CD.
Hence my moniker.
BTW, metric tolerances aren't tighter, it's just that the normally used, smallest increment is .01mm which is approx. .0004". It just seems that way. The truth of the matter is, yes these engines certainly are built to tighter tolerances but nothing closer than I've seen in forty years of drag racing and then restoring Ferraris.
Last edited by madferraristi; Jul 21, 2003 at 11:32 PM.
Let me say this...
My engine builder builds circle car, dragsters, funny cars, and street rods. However, he set my left bank off 3 links. He felt there is a diffrence.
He came highly recomeded and has built some of the fastes motors around my area.
suavy
My engine builder builds circle car, dragsters, funny cars, and street rods. However, he set my left bank off 3 links. He felt there is a diffrence.
He came highly recomeded and has built some of the fastes motors around my area.
suavy
Let's not forget that mod motors have two of those things, and a wide... other thing and maybe some things that George Jetson had to make and that it doesn't use one of those other things.


