351w EFI performance upgrades? - Page 3 - Ford Truck Enthusiasts Forums

Notices
1987 - 1996 F150 & Larger F-Series Trucks 1987 - 1996 Ford F-150, F-250, F-350 and larger pickups - including the 1997 heavy-duty F250/F350+ trucks

351w EFI performance upgrades?

  #31  
Old 12-30-2011, 03:16 AM
UNTAMND's Avatar
UNTAMND
UNTAMND is offline
Postmaster
Join Date: Jul 2009
Location: Lansdale, PA
Posts: 3,598
UNTAMND has a great reputation on FTE.UNTAMND has a great reputation on FTE.UNTAMND has a great reputation on FTE.UNTAMND has a great reputation on FTE.UNTAMND has a great reputation on FTE.
Yeah I heard that the 351 lower intake is a pain to port, but I talked with mike from toohighpsi.com way back and it isn't too bad with the right tools.
I hate that the 351 intake is so flat but they wanted it to be similar height to the 5liter from engine mounts to top of intake.
If I wasn't going to build a blower intake then I'd get rid of the whole truck intake setup and use an aftermarket mustang type intake. But I think I have a great idea and want to try it.

I've used mls gaskets lots of times. The dsm cars I've built run around 40psi and another 34+ psi and need good gaskets. The oem evo gasket kicks butt and so do cometic. I have cometic in my turbo ranger and my tt mustang.
I ran 10psi in my stock musta g motor and that has about 9.2 compression. No worries.
 
  #32  
Old 12-31-2011, 12:22 PM
'89F2urd's Avatar
'89F2urd
'89F2urd is offline
Postmaster
Join Date: May 2011
Posts: 4,539
'89F2urd has a very good reputation on FTE.'89F2urd has a very good reputation on FTE.'89F2urd has a very good reputation on FTE.
Originally Posted by UNTAMND View Post
Yeah I heard that the 351 lower intake is a pain to port, but I talked with mike from toohighpsi.com way back and it isn't too bad with the right tools.
I hate that the 351 intake is so flat but they wanted it to be similar height to the 5liter from engine mounts to top of intake.
If I wasn't going to build a blower intake then I'd get rid of the whole truck intake setup and use an aftermarket mustang type intake. But I think I have a great idea and want to try it.
i have all the right tools, and believe me its still a ton of work. the ports/runners on that thing are so small all over that the sheer volume of material removed will be immense compared with other porting jobs. im not saying its hard, its all easy. just very, very, very time consuming. but, it all falls into the chief law of builds: if its cheap, its not easy. if its easy, its not cheap. gotta put your time in if ya want stuff to be cheap. . .

Originally Posted by UNTAMND View Post
I've used mls gaskets lots of times. The dsm cars I've built run around 40psi and another 34+ psi and need good gaskets. The oem evo gasket kicks butt and so do cometic. I have cometic in my turbo ranger and my tt mustang.
I ran 10psi in my stock musta g motor and that has about 9.2 compression. No worries.
yea it really is a blessing how much abuse MLS gaskets will take. ive actually had the opposite luck with cometic, but ive only used them on diesels. they could have also worked out their issues with them as of late, but regardless just cuz they have a bad name in the diesel crowd doesnt mean that all their products are junk. thats one of the biggest problems with running a business in the internet age. . .it takes way longer to recover from a bad reputation due to all the bashin blogs that fill the net. all factory MLS gaskets are pretty much safe to say theyre good. engineers typically have done enough homework and testing to make em good.
 
  #33  
Old 12-31-2011, 05:26 PM
UNTAMND's Avatar
UNTAMND
UNTAMND is offline
Postmaster
Join Date: Jul 2009
Location: Lansdale, PA
Posts: 3,598
UNTAMND has a great reputation on FTE.UNTAMND has a great reputation on FTE.UNTAMND has a great reputation on FTE.UNTAMND has a great reputation on FTE.UNTAMND has a great reputation on FTE.
Yeah, the first cometic "failed" me when the head lifted at around 34psi. Needless to say I was possed because it was the dumb owner who wouldnt spring for the arp bolts.

The big thing with mls gaskets is that it NEEDS a perfect surface (my opinion) and then it needs indian head gasket shellac or the permatex "super 300" on the water ports and oil drains. At a minimum copper gasket spray. Then after a heat cycle a retorque. This has allowed me to hold 40+ psi in a 2liter dsm.
 
  #34  
Old 01-01-2012, 11:23 AM
'89F2urd's Avatar
'89F2urd
'89F2urd is offline
Postmaster
Join Date: May 2011
Posts: 4,539
'89F2urd has a very good reputation on FTE.'89F2urd has a very good reputation on FTE.'89F2urd has a very good reputation on FTE.
yea the mls gaskets can really take a beating. but like you said, are much less forgiving to uneven mating surfaces and imperfections. studs and MLS gaskets love one another, the even clamping load of studs really allow the MLS to shine. MLS gaskets can hold power levels that would require the use of o-rings in conjunction with a conventional gasket.
 
  #35  
Old 07-13-2016, 12:32 AM
351miller
351miller is offline
Junior User
Join Date: Jul 2016
Posts: 53
351miller is starting off with a positive reputation.
Need more power

I'm new to this site but need some help. I recently bought a camper and need more power. My truck is a 1997 f250 has 351 Windsor 5spd manual and 355 gears. Not interested in changing gears. I have about 2k to spend on engine. Was wondering where to put my money to get most bang for my buck.
 
  #36  
Old 07-13-2016, 01:48 AM
Shadow944795's Avatar
Shadow944795
Shadow944795 is offline
Posting Guru
Join Date: Sep 2013
Posts: 1,022
Shadow944795 is starting off with a positive reputation.
Originally Posted by 351miller View Post
I'm new to this site but need some help. I recently bought a camper and need more power. My truck is a 1997 f250 has 351 Windsor 5spd manual and 355 gears. Not interested in changing gears. I have about 2k to spend on engine. Was wondering where to put my money to get most bang for my buck.
Gears bro.........Gears. 4.10's will get it moving and keep it that way. 3.55's and a camper just aren't gonna mix with even a mildly built small block. You do you but I really recommend it.
 
  #37  
Old 07-13-2016, 02:36 AM
Jordanangel's Avatar
Jordanangel
Jordanangel is offline
Senior User
Thread Starter
Join Date: Dec 2011
Posts: 152
Jordanangel is starting off with a positive reputation.
Originally Posted by 351miller View Post
I'm new to this site but need some help. I recently bought a camper and need more power. My truck is a 1997 f250 has 351 Windsor 5spd manual and 355 gears. Not interested in changing gears. I have about 2k to spend on engine. Was wondering where to put my money to get most bang for my buck.
Honestly like Shadow944795 said gears are the best bang for your buck.

If your only use for the truck is towing the camper and doing truck stuff like my 94 f350 is then I would save the money and just do gears to a 4.10 or lower. Also its really hard to say what you need to do to the engine without knowing the weight of the trailer being pulled.

If you use the truck as a commuter then I understand the reason for keeping 3.55s but that will hurt the towing capability of the truck, I know because I have those gears in my 94 and have 4.10s in my 86 and even tho the 94 is a powerstroke its harder to get moving with the taller gears pulling a trailer, the 86 has a 351w carb but with those 4.10s its a stomp puller and will get things moving easier and without as much stress on the engine and help save the clutch a little.

I plan on switching the gears in the 94 to a 3.73 or 4.10 depending on what gears come in the 05 axles I plan to swap in later since I only use it for towing and truck related things, I have a car for everything else so fuel mileage isn't as much of a concern for me as I'd rather have pulling power for the future toy hauler.
 
  #38  
Old 07-13-2016, 09:33 AM
rla2005's Avatar
rla2005
rla2005 is offline
Post Fiend
Join Date: Oct 2005
Location: Illinois
Posts: 14,719
rla2005 has much to be proud ofrla2005 has much to be proud ofrla2005 has much to be proud ofrla2005 has much to be proud ofrla2005 has much to be proud ofrla2005 has much to be proud ofrla2005 has much to be proud ofrla2005 has much to be proud ofrla2005 has much to be proud of
I am a firm believer in gears but on a limited budget long tube headers, high flow converter and single 2.5" to 3" single exhaust are money well spent. The 1997 5.8L engines should have the better roller cam so a set of 1.7 ratio roller rockers are also highly suggested. Another free boost is bumping the base timing up a few degrees.

All of the above can be done on a $2k budget. It's a good start to see if that is enough to satisfy the power thirst. Ultimately gears are the next step, but there are some horses ready to be let loose before spending that $2k+ on a gear swap. Simply running in 4th gear is an effective gear change.....or shorter tires.
 
  #39  
Old 07-13-2016, 10:49 AM
UNTAMND's Avatar
UNTAMND
UNTAMND is offline
Postmaster
Join Date: Jul 2009
Location: Lansdale, PA
Posts: 3,598
UNTAMND has a great reputation on FTE.UNTAMND has a great reputation on FTE.UNTAMND has a great reputation on FTE.UNTAMND has a great reputation on FTE.UNTAMND has a great reputation on FTE.
Gears are cheap. Go to junkyard and buy the front chuck all setup for $75 probably. Find a complete rear axle for under $150.
It's cheap to swap that stuff out.

The issue with the 5.8 is the crappy heads and intake. 1.7 Roller rockers help a little, because the cam itself is pretty decent, but the heads suck.
Find a set of gt40 heads off a 96 and older explorer, or gt40p heads from 97+ explorer. Gt40p heads will require careful selection of headers to give better clearance of sparkplug wires.
While you're at the junkyard, grab an upper intake from a 5liter... It's actually better.
When you have lower intake off to swap the heads, port your lower intake to the 5liter upper. Focus on the short radius to try and make the passage bigger. The large radius is pretty sharp already and can't be helped a whole lot. Then open up the runners to the intake gasket size. Pay attention, there are a few areas that get thin.
Or just buy a mustang style intake, and use an explorer 65mm tb.
Pacesetter headers I believe are the better headers. Get longtubes because the factory y pipe isn't the best, and I'm sure the cats are used up and partially plugged. Get two 2.5" cats if you live where emissions is needed, and get a nice y pipe to go to 4" exhaust, then buy a diesel exhaust system for it to your the back in factory location. The headers and cats will give you all the back pressure needed. After the cats, bigger is better.

The last thing you need to do, to optimize all your work, and possibly a big chunk of money, is getting the truck Dyno tuned. This will optimize all of your parts, and make it the best possible. Do not buy an online tune, or chip. Go to a Dyno and get it done right.
 
  #40  
Old 07-13-2016, 03:29 PM
351miller
351miller is offline
Junior User
Join Date: Jul 2016
Posts: 53
351miller is starting off with a positive reputation.
Thanks for the input. Was wondering about edelbrocks 3881intake ,gt40 heads, and headers.dont want to lower gears because truck is daily driver. The camper weighs 6800lbs.I have no problems taking off ,have more trouble at higher speeds do to wind block.when I get behind a semi I can roll 70mph in 5th gear. With no wind block 60mph on 4th gear is about it. Any idea how much hp the set up I mentioned would gain .
 
  #41  
Old 07-13-2016, 04:08 PM
UNTAMND's Avatar
UNTAMND
UNTAMND is offline
Postmaster
Join Date: Jul 2009
Location: Lansdale, PA
Posts: 3,598
UNTAMND has a great reputation on FTE.UNTAMND has a great reputation on FTE.UNTAMND has a great reputation on FTE.UNTAMND has a great reputation on FTE.UNTAMND has a great reputation on FTE.
The 3881 truck intake isn't worth the money. You will have more gain for cheaper by just getting a mustang style intake.
That truck intake setup is marginally better than what I said to do with the 5 liter upper and porting stock 5.8 lower.
300-325 hp should be attainable.

There's even a guy running a 460 computer on his truck because it allows more air and bigger injectors.
 
  #42  
Old 07-13-2016, 06:36 PM
westcoasting
westcoasting is offline
Senior User
Join Date: May 2013
Posts: 361
westcoasting is starting off with a positive reputation.
Originally Posted by 351miller View Post
Thanks for the input. Was wondering about edelbrocks 3881intake ,gt40 heads, and headers.dont want to lower gears because truck is daily driver. The camper weighs 6800lbs.I have no problems taking off ,have more trouble at higher speeds do to wind block.when I get behind a semi I can roll 70mph in 5th gear. With no wind block 60mph on 4th gear is about it. Any idea how much hp the set up I mentioned would gain .
There is no reason not to start with gears... a daily driven truck will have not much difference in mpg but the low down power difference is huge.
 
  #43  
Old 07-13-2016, 07:07 PM
Lead Head
Lead Head is offline
Post Fiend
Join Date: Jul 2007
Location: Rhode Island
Posts: 7,855
Lead Head is a name known to allLead Head is a name known to allLead Head is a name known to allLead Head is a name known to allLead Head is a name known to allLead Head is a name known to all
Originally Posted by westcoasting View Post
There is no reason not to start with gears... a daily driven truck will have not much difference in mpg but the low down power difference is huge.
His problem is on the highway, no from a stop. With his camper, 5th gear isn't even usable and he needs 4th. 4.10s will help the situation a little bit, but if he can barely maintain speed in 4th, he needs a bit more power.

Free up the exhaust: High flow cats, better muffler and long-tube headers coupled with a "Six-Liter Tune-Up" will go a long way in helping your towing performance.

The six-liter tuneup consists of new plugs, wires, cap, rotor, etc.. and bumping the base ignition timing to 12* BTDC.
 
  #44  
Old 07-14-2016, 03:24 AM
Jordanangel's Avatar
Jordanangel
Jordanangel is offline
Senior User
Thread Starter
Join Date: Dec 2011
Posts: 152
Jordanangel is starting off with a positive reputation.
Gears will help but only in the fact that it will put the engine in a different RPM at cruise but if your just having trouble maintaining speed then yes making that engine breathe like it should is the best route like these guys have said.

the intake and heads are gonna be the most involved and expense but are probably the biggest gains with the full header, free flow cats and full exhaust, those and a good tune will really let this engine shine. Now it wont be a 460 but will do the job you ask with that size trailer
 
  #45  
Old 07-14-2016, 07:34 AM
'89F2urd's Avatar
'89F2urd
'89F2urd is offline
Postmaster
Join Date: May 2011
Posts: 4,539
'89F2urd has a very good reputation on FTE.'89F2urd has a very good reputation on FTE.'89F2urd has a very good reputation on FTE.
Gt40s, cam, long tubes is literally an increase upwards of 100 hp to the flywheel and can be done for 2k with junkyard heads.

If you're running stockish size tires, I'd take the power...my 37s with 4.10s basically make my final drive 3.55, if it was stock I'd hate it, but I'm happy with how it is especially considering I have a junkyard engine build.
 

Thread Tools
Search this Thread
Quick Reply: 351w EFI performance upgrades?


Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service

© 2018 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.