How do you like your 331 or 347 Stroker?

[Broncotj0]

Just want to get some feedback on your experience with a stroker.

Any cooling issues?

Any problems?

Did you build it yourself?

I know there are alot of guys out there that say not to waste your time with one and just go with a 351 but thats not what I want to do. I don't plan on making 500hp to drag race. So in my mind a small stroker will be more than what I need. Thanks guys,

 

[bowhunter]

I've had 302's in mult broncos...had a 351w in a bronco and have a 347 stroker motor in my current rig.

First, hard to beat a standard 302 for reliability and fuel economy. However, if you are fonna wheel or want a little pep in your step, your gonna have to do something.

Personally, I can't tell a whole lot of difference between the 351 I had and the 347 stroker. Albeit, I have never crawled my 347 and never will. Both motors were built by previous owners in both my trucks. Both motors had lots of extras and are both bad asses.

The 351 I had was geared low and had a np435. My 347 has 4:11's and an nv3550. Not really comparable.

I guess the real question is what are you wanting the motor to do?

 

[Broncotj0]

I'm looking for reliability and more power. I do a fair bit of wheeling but I also drive it down the road. I have a 302 out of a '76 that was rotten like no other. I parted the truck out and kept the drivetrain. My thoughts are that I will build that motor and swap the two out in a day. I'm not real sure of what needs to be changed going from 302 to 351 but I don't want to mess with it. I just put all new exhaust on this and I'm not going to pay to get it redone. With a 302 block I know I won't have any issues with accessories or anything else. Guys have discussed the strength of the 302 and 351 blocks and I understand that the 351 has a little better block. As I stated before I'm not building a drag motor and don't plan on getting 500hp out of it. I would like to see close to a 350/400 range. I just would like a little feedback on other peoples experience with these engines. Thanks,

 

[Kyle.malone]

I have a 331. I will know more about it next weekend. When I had the air gap intake and Demon carb on it, it was a beast!! Only put 200 miles on it before changing things. Origionally had 4.11 gears, C4, Dana20. I (bronco) just went under major surgery and I ended up putting EFI on it with 30 lbs injectors. Everything is ported. Producing about 400hp. It now has a 4r70w, 5.13 gears, and an atlas 4 speed. I'll come back to this thread in 1 week and let ya know what I think.

 

[kb6677]

My buggy was built around a 5.0 block for mockup so we went with a 331. Spent more on it than my 392 but we did "more" to it. It has been "tuned" on the chassis dyno and we are very pleased with it. The entire rotating assemble is balanced and blueprinted. I went with 185 AFR heads, custom ground Erson cam- idle to 4800 (flat on tq and hp on the print out from 5k-5500) so we got what we wanted. Response from off idle to 5k. It is very peppy, but did not put down the tq #'s my 392 did-as expected. I have a false sense of extra pwr with it as the buggy is 1200lbs lighter than the full metal stretched eb with the 392 in it. I run a Ron Davis double pass Al. rad with a matched fan/shroud deal. NO cooling issues. The fan is on a "temp switch". We added a manual toggle in the glove box just in case! I have not had it on an "all day trail run" but the half day deals along with a drive and try this obstacle deal-it has given no trouble-it does like fuel. 30lb squirters, 70MA/TB.
HTH

 

[Broncofan76]

Subscribed Kyle! I wanna know the full report. Sounds awesome.

 

[Broncobowsher]

There is a stroker thread I stared not too long ago. Get feedback on stuff like this. http://classicbroncos.com/forums/showthread.php?t=196925

Having been inside these engines, even building a 330" myself. Do a 351 as a base engine. If you look at the innards of both engines it is easy to see that the 351 is better engineered for work. For myself I had plenty of issues witht he 330" stroker. Some of the highlights (lowlights?), sent the wrong crank with the pre-balanced kit. Torque convertor bottomed in the crank, at the thrust bearing in under 2,000 miles. Never did break in and stop eatting oil. clearance issues with the windage tray/oil pickup tube/oil pan. Plus a few more things that were not necessarly due to the stroker kit. The 351 long rod build, no issues, great motor. Loved the 351 way more then the 330" stroker. The 351 was way cheaper to build as well.

 

[Broncotj0]

Bowsher I understand that you may have had a bad experience with a small stroker and like your 351 build but that is exactly what I didn't want to hear. I'm not going to mess with doing a 351 swap! There are hundreds of guys out there running 331/347's in mustangs and beat the shit out of them on a daily basis without problems. I go wheeling 5 times a year and I drive like I have a brain. Crawling through the woods I'm not going to have a problem with a motor coming apart on me because the block is weaker than another. The argument of this block vs that block or 302 vs 351 can go on all day. I have a 302, that's what I would like to build and I just wanted to know if the poeple that run them like what they have.

 

[Broncobowsher]

Without going into block strength issues (I never had any with either engine)...
I listed a small list of issues that were specific to doing the stroker. I intentionally skipped the non-stroker issues like getting the valvetrain right. So I think my argument still stands.

Swapping a 351 in is simpler and less headache then the stroker. I have swapped from a 302 to a 351, it isn't hard. I have also put the stroker together. When I was done I spent probably 3X on the stroker for no better results then what the 351 got me.

What's the next argument? the little stroker kits are lighter so they rev faster? That may matter in a mustang but in a 2 ton Bronco...

 

[blubuckaroo]

I've driven both and could tell the difference between a stroked 302 and an un-stroked 351W. The 347 was peppier. The difference is in the crank weight. That's why using a lighter Cleveland crank in a 351W has become so popular with the Mustang groups. Don't get me wrong. The heavy rotating mass of the 351W comes in handy in a pick-up or where you want to maintain torque from that mass. And I won't go so far as saying the huge mains of the 351W are unnecessary, but I'll never need that much crank. It all depends on your application and what you like. Zippy or grunt.

 

[NYLES]

One day Im going 347! because like you I just want too and I dont like the 351 conversion issues.

 

[Broncotj0]

Bowsher my situation is that I have a 302 not a 351. I would have to go find a 351 and buy it. Then I would have to go buy a rebuild kit for it and the way I do things I would never do a factory build on it so that would mean the 351 would need to be bored and more than likely stroked as well. Then I would have to do something about heads, rockers, intake, ect. I have an air gap intake, aftermarket dist. and a few other things for my current 302. I believe the 351 is wider than the 302 which would require new $300 exhaust. What fuel injection can I run with a 351? I know how things work with Murphy's law, and there is always something that does not work right. I know a 302 will go right back in where the old one came from but with alot more power. Speaking of power with a 351 base I know it will make more. In my mind that means more broken parts. I don't have 1ton drive, an atlas, and a bomb proof trany. I don't need to make 500hp, a 331/347 in my mind will be more than enough. I personally can't see the need to make over 350hp.

 

[rjrobin2002]

My 347 stroker is a fast revving beast. With my nv3550, 35" tires and 4.56 will haul ass, I can spin both tires all the way through 1st, half way through 2nd, and bark 3rd.

 

[Broncotj0]

Thanks guys for the feedback. Kyle I can't wait to hear what you think about your new mill. I'm going to start getting a parts list put together.

 

[apachetech]

Hey Broncotj0,

Have you heard of Tim Meyer in Fairmont, MN? He is a wizard at building Ford engines!

Like you, I have a 302 that I want to build into a 331 or 347 stroker. Not that I don't like the 351s but I don't want to do a swap here and a swap there. I want to keep my EB in as much a stock fashion as possible with a few mods.

I am glad you brought up this debate again and will keep watch on it.

 

[Broncotj0]

apache, I didn't really want this to go into a 351 vs 331/347 thread. I wanted general feedback from guys that run them currently and to see if they ran into any problems. I would say the feedback was all good other than one poster that had issues. I feel confident that this will be the right decision for me.

Does he have a shop? Contact info? I haven't started to do any research on builders around here. My down fall is I just moved to the area about a year ago and don't really know anyone other than the guys at the parts stores. Thanks,

 

[Broncotj0]

Kyle, Did you get everything up and going? Let us know how it went.

 

[dave67fd]

A stroker is an engine with increased OR decreased stroke. You will gain displacement but short stroke engines like high RPM and is were they make most of their power/torque.

It does have it's advantages but has disadvantages as well. When stroking a 302/351 etc.. to it's limits you loose piston skirt which hurts stability. It also tends to push the piston into the piston ring land area and puts the pin close to the piston dome. This increases heat on the pin which can shorten engine life.

Don't get me wrong you can build a reliable stroker. Has alot to do with the parts purchased and the builder. I'm far from an expert on them but learned this from friends in the buisness as well as what i have read about them in the past. Increased design may have improved these issues over the years i'm not sure.

In my honest opinion if this is to be a street cruiser (with some wheelin). Enhanced reliability may come easier with doing a stock or mild rebuild on the 302, aluminum heads, cam and all the other bolt on's.