• Register Today It's free! This box and some ads will disappear once registered!

building a high performance 4.0

raginred

Member
Joined
May 8, 2000
Messages
15
Reaction score
0
im looking to get a 93-94 4x4 4.0 in the next month(hopefully). i was talking to my friend whose dad works for a ford dealer and he has 2 brand new 4.0 crate motors sitting in his garage. what im going to do is buy that engine a put it in the high milage 93-94. while i have the engine out of the truck and on a stand i want to do some work with it.

1-which cam should i go with? this is going to be my daily driver so i want a good idle. it is also a 4x4 so i want it to give me good low end to mid range torque.
2-i was planing on doing some head work. what all should be done? i was talking to a guy that built a 200+ hp nissan 2.1 v6 and he said that by keeping the intake ports rough and the exhaust ports smooth, the gas was able to burn better and it gave him better milage. is there any truth to that?
3-larger valves. i havent thought about this one alot but is it neccessary? what kind of work would be invovled to do this?
4-i would also like to portmatch the intakes, get a larger throttle body, larger mas air filter, cone filter intake, headers and exhaust.

what injectors will i have to use for this setup? 19#? what kind of milage will this get? this truck will most likely have 33" tires and 4.56 gears.

thanks for any input.
 


Join the Elite Explorers for $20 per year. Gets rid of the ads! New $5 per month "try out" option.

Explorer Forum has probably saved you that much already, and will continue to save you money as you learn how to diagnose fix problems yourself and learn which modifications work without having to experiment on your own. Elite Explorer members see no advertisements, no banner ads, no double underlined links, can add their own profile photo, upload photo attachments in all forums, and Media Gallery, create and save more private Conversations, and more. Join Today. Your support is greatly appreciated.




bluescat

Well-Known Member
Joined
July 9, 2000
Messages
203
Reaction score
2
City, State
Baldwin, MD
Year, Model & Trim Level
2001 X Sport 4X4
OHV or SOHC?

I'm assuming the crated motors are the 4.0 Liter OHV, right? If it's possible you could try to get an SOHC engine instead. This would start you out at 205-210 HP instead of the 165 HP on the OHV. Vanir Technologies is currently working on a new SOHC powerplant. They're the ones that have excelled at build-ups for the 4.0L OHV.
 




raginred

Member
Joined
May 8, 2000
Messages
15
Reaction score
0
yes an it is an ohv engine. i dont want to deal with the wiring required to put that engine in. plus im going to get a very good deal on the ohv crate motor.
 




Maniak

Moderator-Stock 91-94
Elite Explorer
Moderator Emeritus
Joined
February 9, 1999
Messages
12,095
Reaction score
116
City, State
Vail, Arizona
Year, Model & Trim Level
1992 XLT 4x4
Raginred,

Can you get me the part number for the 4.0 crate motor? and the normal price for it (not for that specific motor sitting in the garage but what they would sell it for)


Thanks..
 




Clint

Well-Known Member
Joined
October 12, 2000
Messages
624
Reaction score
0
City, State
Mesa ,AZ
Year, Model & Trim Level
91 sport
when i put my new motor in i had the intake and exhaust ports smoothed and they did a good job too but i did not notice a big hp increase or mpg decrease they told me it would not affect it that much unless i got the larger t.b and m.a.f. maybe this helps




p.s. i got a 100hp increase off
of painting the motor ford blue
seriously
 




SteveVB

Elite Explorer
Joined
July 8, 1999
Messages
2,525
Reaction score
2
City, State
Gaithersburg, Maryland
Year, Model & Trim Level
04 Rubicon w/stuff
Ragin

I just rebuilt my 4.0 and installed a comp cam so I ll have a go at your ?s

1. CAM- Com Cams has 2 grinds, and Cam Craft may have theirs by now. A search of this site should bring up some info.

I used the small Comp Cams cam a HR256 grind it has a bit more lift an dur over stock, I was told the power band shifts up about 300-400rpm. I only have 400miles on the engine but so far the idle is fine, power seems better above 2000, but no loss off idle. I need to change gears and until then really dont think I am using the engine in its power range.

Changing the cam will most likely mean getting new pushrods to keep the lifter preload in spec. due to the non adjustable rockers. Smith Bros can make up some nice 5/16, or 3/8 chrome Moly rodes for less than stock replacements.
Also the valve springs may need to be changed to something with more seat pressure. I didnt, was told that the small Comp Cam doesnt need them(although I used new stock springs), the larger one with more lift and a more aggressive ramp may need them.

2. HEAD WORK

for street engines getting the exhaust ports smooth and leaving the intakes with a stock type finish seems to be the recommendations. On my engine I took off any large casting marks and blended them to the existing port, opened the bowls a little, and removed the egr bumps in the exhaust port. I also smoothed the combustion chamber around the plug boss ( lots of small sharp spots). If I had more time I should have polished the CC more and the exhaust ports, but I didnt and this isnt an all out race engine so... next time.

3. LARGER VALVES

You can install up to 1.8 int. and 1.4 exh with out going out of the hardened seat area( per Sven at Vanir), dont know if it would help much on a low rpm motor though, larger valves would let in mmore FA mixture per lift but I dont know wheter that would affect mix velocity to negate the gains. Recent article in OffRaod about an engine test where they went to samller valves and increased the torque - had to do with mix velocity. Something for a flow bench to figure out- and someone with more money than I can afford to spend at this point!

4. PORT MATCH , HEADERS, INTAKE

Definately port match the intake and the exhaust, I did, these mods may not make big HP gains but probably are worth the effort to make the entry/exit to/from the combustion chamber as restriction free as possible. Idea is not to make them larger but to have a smooth path from the intake to chamber. My lower intake to head area i did a bit of work cleaning up the head to the size of the intake.

All of the above engine work will benefit from headers for the exhaust and a less restrictive intake- search the site for more but I think I am going to run a 63mm TB, with a 70MM MAF.

I have the 19lb injectors and in theory they should be good for 240 hp and with my combo I doubt I will get much above 225hp.

Gas milage I cant help you with, during my breakin with 31" tires, 3.55s and auto I went 260mile on +3/4 tank- just an observation.
 




raginred

Member
Joined
May 8, 2000
Messages
15
Reaction score
0
steve,
thanks for the info. it sounds like youve done what i want to do. plus it looks like your getting pretty good gas milage. hopefully ill have this all done by next month.
 




flyguy

Explorer Addict
Joined
October 17, 1999
Messages
1,858
Reaction score
0
City, State
Gilbert, AZ
Year, Model & Trim Level
'07 XLT V8
Hey guys... Im a little late on this conversation... but maybe I can get some info. Did you do your own head work? Or pay someone? I was looking at the standard abrasives kit... it looks hard... and I would rather have a professional do it. But if its around 600 bucks.. I cant afford that... So.. how much does it cost to have a machine shop do it? And how hard is it to do it yourself? Also... whats involved in the cam install? Is all you need are custom pushrods? Can the cam people tell you the exact length you need? Also... is swapping out the cam pretty easy? I would like to do the heads and cam at the same time if possible...

nick
 




SteveVB

Elite Explorer
Joined
July 8, 1999
Messages
2,525
Reaction score
2
City, State
Gaithersburg, Maryland
Year, Model & Trim Level
04 Rubicon w/stuff
Nick I did the grinding on my heads myself- this is probably the fourth or fifth time I have done a backyard porting job. Its been ten years or more since the last one though. I didnt do anything fancy just some matching and some smoothing. With-out the use of a flowbench you wouldnt want to do a lot of reshaping of bowls/ports, but to match the ports, and smooth and polish the combustion chambers I believe its ok to do in the garage. You could do it yourself if you have the time and the patience. Also be aware that if you screw up you need a new set of heads. Check out some books on engine blueprinting and building see whats involved.

Cam - you had the heads off before so you were almost there- you go that far and also have to remove the front cover to get the timing chain and cam out.

Pushrods, I have the finished length provided by Sven at Vanir for the Comp Cams cam for stock deck and cylinder heads so you could go from that for push rod length. But I would double check the length after the cam is installed and before you buy the pushrods to make sure you are ordering the correct length. Go to Crane Cams site they have a good set of instructions for checking the length, its the third or fourth paragraph down. http://http://www.cranecams.com/hydlfaq.htm
 




Top