Hi guys...I am looking at several complete 351HO's for a swap with a 302EFI...I understand it has a 17" air cleaner, and a low-restriction exhuast, but what else?

Thanks for the help





Evan A.K.A. PastMaster
1993 F-150 302/E40d XLT
1989 F-150 302/Aod 4x4 XLT Lariat

 

i personally have a 351ho in my 85 f150, and i love it, your right about the air cleaner and exhaust, but it also has a holley/motorcraft 600 cfm 4barrel, it sounds sweet, and of course it has a 4-v manifold, im not sure if there is anyhting else....??

 

I'm not sure about the 351s, but the 302HO has a different firing order, which means a differnt cam and also a different crankshaft I think.

 

The HO also will have larger ports in the head to accomodate the 4 bbl carb and I think the valves are also a tad larger; anyway it has a lot better flow on the intake side than the standard 2V.

'82 F150 w/351W (orig 300 I6)
Slik

 

The HO engines come with a roller timing chain as well, rather then the normal plate/link/riveted chain that you see on production engines from the past.Can't remember if it was single or double row though.
Phillip

 

i was pretty sure about it having slightly better intake flow in the heads, and larger valves, but i did not wanna say anyhting unless i was positive

 

>I'm not sure about the 351s, but
>the 302HO has a different firing
>order, which means a differnt cam
>and also a different crankshaft I
>think.

The 302 Ho has a different firing order from other 302s, but not 351s, the 351 H.O. has the normal 351 firing order. Changing the firing order only requires different cam timing, but probably should use a different cam. I have a 300 I-6 that has a reverse firing order, the cam is 180 degrees off, but, other than being nearly impossible to time, it runs no different than any other 300.
Evan MacDonald

 

It has a 4180 4-barrel Holley...I am thinking about getting one, for a rebuild in a 89 F-150 4x4.





Evan A.K.A. PastMaster
1993 F-150 302/E40d XLT
1989 F-150 302/Aod 4x4 XLT Lariat

 

What exactly was this "lower restriction"? My dad had a 86 with a 351Ho and a c-6...He said it was a Gasoholic, but it ran liked a scalded monkey





Evan A.K.A. PastMaster
1993 F-150 302/E40d XLT
1989 F-150 302/Aod 4x4 XLT Lariat

 

>I have a 300 I-6 that has a reverse firing order, the cam is 180 degrees off, but, other than being nearly impossible to time, it runs no different than any other 300.
Evan MacDonal<

Is that because of a HP cam you installed or something else ? I once had a Courier that had a 2.3 Ford engine with a bad cam. It was hard times then so I got a cam out of a wrecked Ranger and when I raised the hood to pull the part myself, I found a 2.0 LPG gas engine under there.Being the experimental type, I said what the heck and pulled the cam & lifters anyway.
Stuck it in my Courier, the lifters were too big for the bore(i checked the parts books and couldn't not find a different # for lifters on 2.0 or 2.3 ?)so I reused the orginal ones after I compressed them in a vise. Started up fine, went test drive and noticed a tremendous amount of torque! Had to have been the timing & lobe speration built into the LPG cam! That puppy pulled like a son of a gun ! I wonder what a LPG cam would do in a 300 on gas ?
Phillip

 

I am not sure whey the firing order is backwards, but, I know the timing gears were replaced, so it opens up the possibly the crank was rotated 180 degrees with the timing gears off. I also wonder what the LPG cam will do, now I'm gonna have to find out My son rebuilt the 300 that is in his truck, I'm not sure what he did, he put $2-3000 into the truck, but, it is pushing 310 hp and 400 ft-lbs at the rear wheels, all I know is it has a large single 4 barrel, dual exit clifford header, a new cam, and some other goodies, none of which he will tell me the specs of, I do know he had the head ported and polished, and set up for larger valves, amd he probably had much more done, none of which he will disclose to me, guess he doesn't want me to find out how much he put into it.
Evan MacDonald

 

>I am not sure whey the firing order is backwards, but, I know the timing gears were replaced, so it opens up the possibly the crank was rotated 180 degrees with the timing gears off. <
I can shed some light on that one. You see, and a lot of people don't know about this,when you install cam gears(or chain & sprocket)and the marks are dot to dot, #1 piston is at TDC,but it is on theintake stroke, not the fire stroke !In fact, with the cam in that position,it is the 4th cylinder in the fire order(for a 6, the 5th for an 8)that is at TDC ready to fire.So what happens is a lot of people will stab the distributor rotor to #1 on the cap ,and then find out she won't even pop when trying to start,and then go swapping wires here & there around the cap until they get something to happen,or, pull the #1 plug and spin to find compression,then re-stab the dist. The later choice is the way to go if you don't want the next mechanic to find out what you did wrong. The easier way would be to just munipulate the wires around the cap, so dont be surprised when you find a different wire then #1 on the cap in the #1 position as marked on the cap.I think the only engines that doesn't apply to is the Pontiac V-8 and the International v-8, but I'm open for debate !This is something I learned the hard way myself and I still grin whenever I here that someone else has made such an error. What's bad is the books really don't warn you of this in most cases.
Phillip

 

Hey did you ever do the swap? I am getting ready to do the same swap and wanted to see how yours went. According to Ford Hot Line the 351HO has a marine cam for lots of low end torque as in towing applicatons. Send me some email quick if you can because i have a line on some engines that won't last and I need to move pretty quick if you know what i mean. Thanks
reuel@wirespeed.com

 

Phillip ,
I learned the hard way about the 345 in the International Scout ...first time I had ever seen one like that .
Paul

 

The 351 high output has the same firing order as the H.O. 302. The reason is because they share the same camshaft. What make it a H.O is the 9:1 compresion ratio due to the forged flat top piston, which help the engine from busting a piston, and breaking a scert. The 86 up had a roller cam and lifters and a double roller timing chain which helped reduce friction and inprove proformance. The head do have a little larger intake runners but the exhuast is about the same. The only problem you would run into is with the fuel injection, the intake on the 302 will not fit, you could change it to a carb, but a good fuel injection works much better and more ecnomical. Finding a intake for it would not be hard, look in a junkyard.

faseddie