All SOHC Mods

[BonesDT]

What are all the performance mods you can make for the SOHC? These are all the ones i can think of:

1. K&N FIPK intake kit (or the next two)

2. KKM filter

3. Granatelli MAF sensor

4. Throttle body spacer

5. custom cat-back exhaust (headers, free-flow cats, or extra-large pipes allow too little back-pressure)

6. Superchip, Diablo chip, or JET chip (are these all of them? which is best?)

7. Jacobs Ignition System (does this work???), wires plugs (which sounds like a waste of money)

8. Upcoming Xplorer Xpress Supercharger

Can anybody else think of more mods, or different companies?

My plan is to pimp out the engine as much as I can and then finish it off with a chip (which needs to be programmed with all of the mods) and then have adding the supercharger in the future. Right now, i have the KKM filter and am working on a custom dual cat-back with flowmaster 40. Im deciding on also getting the granatelli MAF, K&N FIPK, or throttle body spacer. After all that, then i can get my chip. i think ill skip the ignition system unless you guys think its significant gains. maybe one day ill have $3600 for the supercharger.

 

[Alec]

It all depends on how soon you want to get the supercharger.

You already have the KKM. You don't need the MAS unless you get the supercharger. You don't need the TB spacer period. If you're not gonna get headers or a highflow cat when you get the supercharger you can go ahead and do exhaust work now. If you're planning on getting the s/c and doing exhaust work with that, you'd need to redo any catback you get now. As for the computer, it depends on what comes with the EE s/c kit. It may come with a chip or computer already. If it doesn't, you'll need to hit the dyno to custom tune a chip. A chip does not really need to be custom tuned for just intake, exhaust, and MAS.

If you're not getting the s/c soon, go ahead and just get the exhaust and chip. When you do the s/c you can do the chip and exhaust again and add other things.

If you're getting the s/c soon then wait to do everything at once.

 

[ToneDog]

SOHC S/C Question

Alec,

How does adding a s/c to an SOHC effect reliability? Is there alot of constant maintenance? How about motor life you think that adding a s/c to an SOHC with 48k on it already (babied 48k) in perfectly running condition will kill "her".
I am not looking to go "gunning" it all over town or racing, I really just want to know that if I need it and when I need it, the low end power (which is too low stock IMO) is there.

Thanks,
Ton

 

[Alec]

If you tune it right it would be ok for the motor, but with all that power the tranny will probably take a crap.

 

[aldive]

A Granatelli MAF does indeed work well with the SOHC as does the TB spacer' yes, I have both installed.

For a chip I would definatelu go with Apten.

Good luck....

 

[Magicfan25]

Really for all that cash, and like Alec said, the trans will likely die. Might a 5.0 swap be cheaper (if you have help and dont have to pay for all the work).

I'm sorry, but the EE SOHC s/c kit is a waste. I'd bet money you could go to your local race shop and do it cheaper. And chargin you an extra grand for a kit that WILL ping? Just sounds irresponsible to me.

The M62 is a big part of the problem. If you dont wanna deal with hood clearance issues, at least go with a whipple charger of equivalent size.Whipple Chargers appear to be shorter than Eatons, so a bigger one may fit. With the same pulley they make more boost and make more power via lower intake temps.

I will say the EE kit MAY redeem itself to some degree if they actually give torque numbers instead of just horsepower.

 

[TarHeel085]

add another DIY SOHC mod: mud

 

[Alec]

Well I have about 375 tq at the crank. The SOHC kit should make about that or more.

I will say that my kit is about the same as the SOHC kit will be, and the money was worth it. According to Eaton's website and all the reading I've found for the blowers, the 4th gen M62 is a good match for the SOHC.

 

[Doug904]

Everyone has posted great responces to this post but I so wanna add just a little by saying stay far away from Jacob's ignition products. Too many problems from too many people. If you just have to have a aftermarket ignition get the MSD DIS-4 but you must splice into the wiring harness, something I just don't care for. The installation kit they have is for the 4.6's not the 4.0's and no it wont work. You don't need an aftermarket ignition on a 4.0 until you reach above the 300hp range and I can tell you from personal experiences that by the time you reach that much with a 4.0 a aftermarket ignition will be one of the cheapest items you have on your entire vehicle.hahahah.

On a lighter side I have a dyno run scheduled for mon. January 20th with one of the kits I've helped design for the SOHC 4.0. It has the larger Eaton M90 supercharger and I can't wait to see some numbers. I'll keep you guys updated on the results.

Later Doug904.

 

[Doug]

Maybe this is a dumb question but if youre serious about power why dont you do some real motor work instead of bolting things on? on my ohv motor I plan on porting and polishing the heads, roller rockers, cam, milled crank and a few other little things.

 

[Doug904]

Originally posted by Namitey
Maybe this is a dumb question but if youre serious about power why dont you do some real motor work instead of bolting things on? on my ohv motor I plan on porting and polishing the heads, roller rockers, cam, milled crank and a few other little things.

I can see that you've never done any " real motor work" to a SOHC 4.0. First off it doesn't have rocker arms but cam followers which are roller. Noone makes any kinda aftermarket cams for them yet and even so it would require 10 times more work on a SOHC then on a OHV to change BOTH camshafts. Its not a 4.6 and one cam chain is up front and the other is in the rear. I could go on but its not worth it, do all the bolt ons and then if thats not enough use some sort of forced induction. You will never get a natraully aspirated 4.0 in the extremely high HP numbers, maybe around 225-240 with a SOHC.

Later Doug904.

 

[Alec]

Nam,
My next motor mods are gonna be:

Early model "worked" heads, lowering my compression.
New lifters, pushrods, etc
Injectors
MAS
new pulley for more boost

I'm not gonna do the cam or work on the bottom end unless those parts are damaged. I don't want to pull the motor to do this work. Plus, I don't want to go too aggressive because I don't want my tranny to explode. I figure with those mods I'll approach 350 hp.

 

[Doug]

Originally posted by Doug904
I can see that you've never done any " real motor work" to a SOHC 4.0. First off it doesn't have rocker arms but cam followers which are roller. Noone makes any kinda aftermarket cams for them yet and even so it would require 10 times more work on a SOHC then on a OHV to change BOTH camshafts. Its not a 4.6 and one cam chain is up front and the other is in the rear. I could go on but its not worth it, do all the bolt ons and then if thats not enough use some sort of forced induction. You will never get a natraully aspirated 4.0 in the extremely high HP numbers, maybe around 225-240 with a SOHC.

Later Doug904.

Well if you paid attention instead of being a smartass you'd notice those where things i was doing to my OHV motor NOT a SOHC.

 

[Muskrat]

while we're here, since when do SINGLE OVER HEAD CAM engines have 2 camshafts?

 

[Robb]

Originally posted by Muskrat
while we're here, since when do SINGLE OVER HEAD CAM engines have 2 camshafts?

How many heads are there?

Robb

 

[99exEB1]

Namitey - I think that doug ment that there wasnt many non-bolt on things for the SOHC, so all the things you are planning on doing to your OHV you cannot do to a SOHC.

 

[Doug]

Oh i know you cant do all the things i plan on doing but you can do some of them. you can still port and polish the heads and get the crank milled. Hell you could get new pistons, and lighter connecting rods. there is alot you can do it all depends on how much you want to spend.

 

[99exEB1]

Originally posted by Namitey
there is alot you can do it all depends on how much you want to spend.

It always comes down to that.

 

[Doug]

Alec, I was talking to a friend of mine and he recommended strengthing up the bottom end. and while i dont really want to put a lot of money into the bottom end i think a milled crank would be a good compromise. Fortunantly for me i have a 2nd 4.0 ohv motor so i can do all the stuff at the speed i want.
And since i dont have a S/C I definantly want to do the cam and rods and such. Id run higher lbs injectors but my gas mileage sucks as it is. I wonder if its possible to run sohc pistons in an ohv motor for higher compression..

 

[Doug904]

I didn't mean to come across as an azz but sometimes I do sorry for that. I do ALOT of 4.0 performance rebuilding, everything from OHV's to SOHC's. I can give you some great recommendations as to which companies to use and whats available for you.

Yes, the SOHC and OHV have the same bore's so you can use the pistons from either one in either block. The major thing with the flat topped SOHC piston is with the small combustion chamber, 68cc in the early styles and 58cc in the later, the compression ratio will climb to a almost unusable 12 or even as high as 13:1. Since a 4.0 doesn't have a distributer not a cheap way to control ignition timing this would create one heck of a monster to get to run right without severe detontation. Since I see that you don't wanna increase injectors sizes due to fuel milage concerns I doubt this would be a worth while mod either. If you want to see some SOHC pistons just ask, I have a few pictures of some I've removed from the block.

On the other hand I use OHV pistons in the SOHC's to reduce the compression ratio from the stock 9.7:1 to a boost friendly 8:1, of course this is + or - a tenth or two of a point. This seems to work well with the supercharged SOHC's up to around 10-12psi of boost after which you just have to use some form of detonation supression.

If you have any questions dealing with the 4.0 feel free to ask, I should have my site up soon with some great 4.0 info.

Oh and one little thing though, your terminalogy isn't exactly right, you mean having the crankshaft turned, ground, or polished not milled . This won't give you any additional power, just clean up the surface to ensure proper bearing wear. Now you can have your crankshaft offset ground to increase the stroke but you'll never do enough to justify the addtional cost, this can be money well spent on other parts of the engine.


Later Doug904.