351m conversion to 400 question for Bubba

Reply Subscribe

Thread Tools

Search this Thread

Sep 28, 2003 | 12:23 PM

79_custom

Thread Starter

Senior User

Joined: Jun 2003

Posts: 295

Likes: 0

From: Pikeville, KY

351m conversion to 400 question for Bubba

I think I want to go that way..Right now I have a good street engine but I want more torque, I dont want to replace my engine with a 429 or a 460. Ive alrady got alot of money in my 351m right now...

So really how much more power can I get out of this setup when I convert my 351m to a 408, I think thats what it would be..my engine now is punched .030 over, .510/ .536 lift cam, my heads have been shaved .030", 3-angle v-job, new stainless valves, new brass guids, high performance double valve springs, Roller rockers, and the ports cleaned up..The intake is a performer 400, with a 750 carb, I know the carb is too big but it was gave to me.. I got a edelbrock calibration kit I used to jet it down some, runs better now dont flood half as bad, but its still hard on plugs.. Long tube hedman headers.. Accel coil and pulg wires..I think that all I have done to the engine right now

I would like for someone to help me out some on my question, cause I dont want to do this and it not help out much on my power.?confused?

-Custom

Sep 29, 2003 | 02:05 AM

willd

Elder User

Joined: Oct 2002

Posts: 743

Likes: 1

About 25-30 h/p more and 50-75 ft/lbs is a good guesstimate.

Sep 29, 2003 | 11:53 AM

bubbaf250

Posting Guru

Joined: Aug 2000

Posts: 1,127

Likes: 3

From: (near) Denver USA

Without knowing how much power your engine puts out now, it's pretty hard to say how much more it would put out if you changed something.

If you could give more detailed cam specs (such as valve timing events at specified lift), maybe one of the guys on here with Desktop Dyno software can run some theoretical numbers for you.

IMO, if you've got a recently built engine, and you're not dissatisfied with the performance you have now, your money is better spent on tuning the engine you have to optimize it.

Sep 29, 2003 | 10:43 PM

79_custom

Thread Starter

Senior User

Joined: Jun 2003

Posts: 295

Likes: 0

From: Pikeville, KY

[QUOTE]Originally posted by bubbaf250

If you could give more detailed cam specs (such as valve timing events at specified lift), maybe one of the guys on here with Desktop Dyno software can run some theoretical numbers for you.

CAM SPECS:

Cam lob lift/ int .295 exh. .310
valve gross lift.. int. .510/ exh.536
Duration @.050" int. 214/ exh.224
advertised duration @ .006" inta.280/ exh.290

Cam timing:

INTAKE EXHAUST
opens @ 0 BTDC @ 49 BBDC
closes@ 34 ABDC @ 5 BTDC

Lobe seperation 110

intake lobe centerline 107
Exhaust lobe center line 117

thats all the cam specs that I have.. I hope it helps anyone out

Thanks

Custom

Last edited by 79_custom; Sep 29, 2003 at 10:46 PM.

Sep 30, 2003 | 08:21 AM

84mustang

Freshman User

Joined: May 2002

Posts: 37

Likes: 0

From: Minnesota

Using Desktop Dyno, I estimated 8.5:1 compression for the 351.
It came up with 381 Ft/lbs of torque @ 3500 RPM
and 325 HP @ 5000 RPM

using 9.5:1 with the 400 crank, everything else the same it says
443 ft/lbs @ 3000 RPM and 338HP @ 4500 RPM

That was done using head flow data that someone else had posted, and long tube headers with Mufflers.

Hope that helps,
Jerry

Oct 1, 2003 | 10:04 PM

79_custom

Thread Starter

Senior User

Joined: Jun 2003

Posts: 295

Likes: 0

From: Pikeville, KY

Quote:

Originally posted by 84mustang
Using Desktop Dyno, I estimated 8.5:1 compression for the 351.
It came up with 381 Ft/lbs of torque @ 3500 RPM
and 325 HP @ 5000 RPM

using 9.5:1 with the 400 crank, everything else the same it says
443 ft/lbs @ 3000 RPM and 338HP @ 4500 RPM

That was done using head flow data that someone else had posted, and long tube headers with Mufflers.

Hope that helps,
Jerry

Its bound to have more than 325 horse I think... because it ran a 13.64 @97 mph about two weeks ago at the track, and that was on street rubber. I would love to get it down into the 12's, I was just thinking of Ideas to try and get it in the 12's if that was possible with a 351m..lol

Custom

Oct 1, 2003 | 10:38 PM

stangman67

Senior User

Joined: Jul 2003

Posts: 137

Likes: 0

Youve got torque and that =speed

10 Ugly Ford Trucks That We Still Kinda Love

Joe Kucinski

10 Things Every Truck Owner NEEDS (2026 Edition)

Michael S. Palmer

Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath

Verdad Gallardo

Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer

Joe Kucinski

2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)

Brett Foote

Top 10 Ford Truck Tragedies

Joe Kucinski

AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make

Brett Foote

Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!

Michael S. Palmer

Ford's 2001 Explorer Sportsman Concept Looks For a New Home

Verdad Gallardo

10 Best Ford Truck Engines We Miss the Most!

Joe Kucinski

Oct 2, 2003 | 12:12 AM

79_custom

Thread Starter

Senior User

Joined: Jun 2003

Posts: 295

Likes: 0

From: Pikeville, KY

a C6 trany takes about 20% of that power away, so that would be less than your talking about, but I guess it does sound right,

Thanks for your help..

Oct 2, 2003 | 03:39 AM

#10

willd

Elder User

Joined: Oct 2002

Posts: 743

Likes: 1

I was reminded tonight why I love the 400 for torque. I went and bought a 25' travel trailer. On the way home the fuel pump started to go south. Anything more than 1/4 throttle or 2000 rpm it would start to nose over. ( Yeah I checked the filter, no such luck this time.) It pulled the trailer 20 miles uphill to my house with me never having to get out of 4th gear most of the way. Just chugging along at 1500 and pulling like mad.