302 build questions
Thread Starter
|
Junior User
Joined: Oct 2019
Posts: 96
Likes: 0
302 build questions
I just got a 1990 ford f150 with a 302 and its knock knock knocking on heavens door its time for a rebuild but I would like to build it for power is it possible to use a 408 crank in a 302 block or would a 347 be the best way to go also was thinking of carb swapping it whats the best way to make power with these? thanks in advance for any info
Matt
Matt
Lead Driver
Joined: Apr 2008
Posts: 6,938
Likes: 13
Yes, only difference is its about 1.5" taller and wider. You will need a different flywheel or flexplate due to the different external balance.
Thread Starter
|
Junior User
Joined: Oct 2019
Posts: 96
Likes: 0
what kind of horse can I make with a 347 or would it just be a no brainier to use a stroked 351?
Super Moderator
Joined: Apr 2004
Posts: 34,491
Likes: 2,805
Some comparison can be had here. A 450HP 347 is going to be a high rpm, rough idle, race car like motor. A 450 HP 408 will be a little tamer, with a lot more torque in the low and mid range. Still a "race car" like engine.
https://www.prestigemoto.com/custom-...k-engines.html
Is this thing going to be a truck? Or are you going to drag race it?
The most basic general rules of engine building: "The more you do to improve the performance of an engine, the higher you move the RPM where peak power is reached." "As you increase the size of an engine, all else remaining the same, the lower the RPM where peak power is reached".
This is for naturally aspriated engines.
What is your budget for this project? You can see the prices in that link.
IMO a stock late model 351W with the stock roller cam, plus a decent dual plane manifold and 650CFM carb will give you plenty of torque and about as much horsepower as your rear suspension will put on the ground if driven easily, and more speed than your brakes and suspension will handle.
https://www.prestigemoto.com/custom-...k-engines.html
Is this thing going to be a truck? Or are you going to drag race it?
The most basic general rules of engine building: "The more you do to improve the performance of an engine, the higher you move the RPM where peak power is reached." "As you increase the size of an engine, all else remaining the same, the lower the RPM where peak power is reached".
This is for naturally aspriated engines.
What is your budget for this project? You can see the prices in that link.
IMO a stock late model 351W with the stock roller cam, plus a decent dual plane manifold and 650CFM carb will give you plenty of torque and about as much horsepower as your rear suspension will put on the ground if driven easily, and more speed than your brakes and suspension will handle.
Hotshot
Joined: May 2003
Posts: 11,141
Likes: 25
From: south louisiana
Some comparison can be had here. A 450HP 347 is going to be a high rpm, rough idle, race car like motor. A 450 HP 408 will be a little tamer, with a lot more torque in the low and mid range. Still a "race car" like engine.
https://www.prestigemoto.com/custom-...k-engines.html
Is this thing going to be a truck? Or are you going to drag race it?
The most basic general rules of engine building: "The more you do to improve the performance of an engine, the higher you move the RPM where peak power is reached." "As you increase the size of an engine, all else remaining the same, the lower the RPM where peak power is reached".
This is for naturally aspriated engines.
What is your budget for this project? You can see the prices in that link.
IMO a stock late model 351W with the stock roller cam, plus a decent dual plane manifold and 650CFM carb will give you plenty of torque and about as much horsepower as your rear suspension will put on the ground if driven easily, and more speed than your brakes and suspension will handle.
https://www.prestigemoto.com/custom-...k-engines.html
Is this thing going to be a truck? Or are you going to drag race it?
The most basic general rules of engine building: "The more you do to improve the performance of an engine, the higher you move the RPM where peak power is reached." "As you increase the size of an engine, all else remaining the same, the lower the RPM where peak power is reached".
This is for naturally aspriated engines.
What is your budget for this project? You can see the prices in that link.
IMO a stock late model 351W with the stock roller cam, plus a decent dual plane manifold and 650CFM carb will give you plenty of torque and about as much horsepower as your rear suspension will put on the ground if driven easily, and more speed than your brakes and suspension will handle.
Trending Topics
Lead Driver
Joined: Apr 2008
Posts: 6,938
Likes: 13
I mean, a 347 is practically a 351. If you want to get over technical, it IS the same minus .1" of stroke, and plus .030" bore. Beyond that, the 347 doesnt have as favorable rod ratio, has shorter rods, less stable ring pack, higher piston speed / inertia, higher cost of parts (compared to a 351 using factory rotating assembly). I personally have never understood the merits of a 331/342/347. Just a put a 351 in. Now, there are some abstract reasons, class rules, and exceptionally tight engine bays. Size and weight difference between a 351w and a 302 are pretty marginal, not so much between a 351 and a 429/460, not to mention now you have to change engine mounts, bellhousing, and often times, front suspension. For this reason, im going 351 based in my 69 Fairlane. Will build either a 393 clevland or a 408w. I have both, both need rebuilt, the w is in much worse shape than the c but is a 69 block out of a fairlane so i kinda want to go this route if the block is salvageable. If somehow a F4TE 351 falls into my lap (like i was originally looking for) i will ring bearing and hone it, AFR 165s, and a 290 something duration cam with .580 lift and make ~400hp. If its a 408 afr 185s very similar cam (the strokers dont like to spin all that hard) and make 425-450hp with more torque and lower rpm.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
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
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Thread Starter
|
Junior User
Joined: Oct 2019
Posts: 96
Likes: 0
Some comparison can be had here. A 450HP 347 is going to be a high rpm, rough idle, race car like motor. A 450 HP 408 will be a little tamer, with a lot more torque in the low and mid range. Still a "race car" like engine.
https://www.prestigemoto.com/custom-...k-engines.html
Is this thing going to be a truck? Or are you going to drag race it?
The most basic general rules of engine building: "The more you do to improve the performance of an engine, the higher you move the RPM where peak power is reached." "As you increase the size of an engine, all else remaining the same, the lower the RPM where peak power is reached".
This is for naturally aspriated engines.
What is your budget for this project? You can see the prices in that link.
IMO a stock late model 351W with the stock roller cam, plus a decent dual plane manifold and 650CFM carb will give you plenty of torque and about as much horsepower as your rear suspension will put on the ground if driven easily, and more speed than your brakes and suspension will handle.
https://www.prestigemoto.com/custom-...k-engines.html
Is this thing going to be a truck? Or are you going to drag race it?
The most basic general rules of engine building: "The more you do to improve the performance of an engine, the higher you move the RPM where peak power is reached." "As you increase the size of an engine, all else remaining the same, the lower the RPM where peak power is reached".
This is for naturally aspriated engines.
What is your budget for this project? You can see the prices in that link.
IMO a stock late model 351W with the stock roller cam, plus a decent dual plane manifold and 650CFM carb will give you plenty of torque and about as much horsepower as your rear suspension will put on the ground if driven easily, and more speed than your brakes and suspension will handle.
Lead Driver
Joined: Sep 2003
Posts: 7,014
Likes: 207
From: SoCal
I did that with my 302; long duration, high lift cam with 110 lobe separation in the hopes of getting more power. It ended up with lopey idle, but it also stinks to high heaven because it's dumping a lot of raw gas out the exhaust. At those low idle speeds, it does not develop enough vacuum to operate the brakes, especially when cold. I have to keep the idle up in order to operate the brakes, which takes some of the lope out. I'm now regretting going with such an aggressive cam.
Thread Starter
|
Junior User
Joined: Oct 2019
Posts: 96
Likes: 0
I did that with my 302; long duration, high lift cam with 110 lobe separation in the hopes of getting more power. It ended up with lopey idle, but it also stinks to high heaven because it's dumping a lot of raw gas out the exhaust. At those low idle speeds, it does not develop enough vacuum to operate the brakes, especially when cold. I have to keep the idle up in order to operate the brakes, which takes some of the lope out. I'm now regretting going with such an aggressive cam.
Hotshot
Joined: May 2003
Posts: 11,141
Likes: 25
From: south louisiana
I did that with my 302; long duration, high lift cam with 110 lobe separation in the hopes of getting more power. It ended up with lopey idle, but it also stinks to high heaven because it's dumping a lot of raw gas out the exhaust. At those low idle speeds, it does not develop enough vacuum to operate the brakes, especially when cold. I have to keep the idle up in order to operate the brakes, which takes some of the lope out. I'm now regretting going with such an aggressive cam.
Lead Driver
Joined: Sep 2003
Posts: 7,014
Likes: 207
From: SoCal
It is a Holley 600 cfm carb with vacuum secondaries.
My choice of cam was limited as I was using a retrofit roller in a 1968 block. I had read some bad reviews of link-bar lifters, so I avoided those. I ended up using the dog-bones and spider setup of the 80's-90's SBF:
https://photos.google.com/share/AF1Q...ZEOUVmWjRfSFl3
Maybe I didn't search long enough, but I could not find wider LSA cams at the time.
Sorry, I feel like I'm hijacking the thread again.
My choice of cam was limited as I was using a retrofit roller in a 1968 block. I had read some bad reviews of link-bar lifters, so I avoided those. I ended up using the dog-bones and spider setup of the 80's-90's SBF:
https://photos.google.com/share/AF1Q...ZEOUVmWjRfSFl3
Maybe I didn't search long enough, but I could not find wider LSA cams at the time.
Sorry, I feel like I'm hijacking the thread again.