Stroker motor talk!-Threads merged

[Andy Jones]

I'm gonna be doing a stroker motor in my Bronco. What are some pro's and Cons of a 347 vs a 408? Aluminum heads vs iron heads? Etc.. I'm going through blueprint for my motor package.
http://blueprintengines.com/

[robertcrav]

Well...

In my opinion, our big heavy bricks need torque, so I'm going to vote 393/408...Also the 351w block is beefier than the 302 based block unless you are going to run an SVO/FRPP 4 bolt block

[ChaseTruck754]

My vote is also 393. It's what I was going to do. Not big enough to "stretch" how far I'd go with boring a stock block, but still plenty of power to be had.

I'd start with a 351w if you are having something built - assuming that this thing won't need to be smogged so a "motor swap" is ok if your bronco had the 351w stock.

[Agui-E7TE]

I also vote 393/408 stroker but I also wouldn't rule out a nice 331 stroker. My '89 Mustang Notchback has plenty of punch with a built 306. My seat of the pants Dyno tells me over 400 HP and I wouldn't hesitate to run it in my Bronco at all even though it weighs 3200 pounds more than the Mustang.

[robertcrav]

I also vote 393/408 stroker but I also wouldn't rule out a nice 331 stroker. My '89 Mustang Notchback has plenty of punch with a built 306. My seat of the pants Dyno tells me over 400 HP and I wouldn't hesitate to run it in my Bronco at all even though it weighs 3200 pounds more than the Mustang.

Yeah, but torque early on in the RPM band is going to get the truck moving...not high RPM Hp

[Andy Jones]

Blueprint doesn't offer a 393 package.. And either motor I go with will have a little Danzio magic waved over it.

[shockseals.com]

I'm gonna be doing a stroker motor in my Bronco. What are some pro's and Cons of a 347 vs a 408? Aluminum heads vs iron heads? Etc.. I'm going through blueprint for my motor package.
http://blueprintengines.com/

Aluminum heads solely to take some weight off the front of the pig.

[gunit]

I have 331 roller with GT40 heads, a Comp Cams 270h cam, 9.8:1 compression, BBK shorty headers, Holley 600 carb on an Edelbrock Air Gap manifold. It is good motor for a Prerunner;
it loves to rev and pulls really hard between 3000-4500 rpm. It is not the best at the bottom end of the powerband but if you are driving hard it is impressive. Most people riding with me don't believe it when I tell them that it a 302 based engine.

Another consideration is that a 302 complete engine with iron heads weighs 440# and a 351 weighs 535# with aluminum heads you save another 40#. A 100# off the front suspension can't be a bad thing.

Sometimes I think that I should have gone with a 351 block and built a bigger displacement engine with more low end torque but then again after over 11,000 miles of hard high speed prerunnig I have not broken anything in the drivetrain(knock on wood).

[Seabass]

I'd like to bring up the cost of supporting modifications for the strokers. At what point does everything else need to be upgraded to support the extra displacement I'd love a 408 but I'm thinking a higher compression357 may get me good numbers and save me the cost of injectors, fuel pump mass airflow meter ect thoughts?

[Agui-E7TE]

I have 331 roller with GT40 heads, a Comp Cams 270h cam, 9.8:1 compression, BBK shorty headers, Holley 600 carb on an Edelbrock Air Gap manifold. It is good motor for a Prerunner;
it loves to rev and pulls really hard between 3000-4500 rpm. It is not the best at the bottom end of the powerband but if you are driving hard it is impressive. Most people riding with me don't believe it when I tell them that it a 302 based engine.

Another consideration is that a 302 complete engine with iron heads weighs 440# and a 351 weighs 535# with aluminum heads you save another 40#. A 100# off the front suspension can't be a bad thing.

Sometimes I think that I should have gone with a 351 block and built a bigger displacement engine with more low end torque but then again after over 11,000 miles of hard high speed prerunnig I have not broken anything in the drivetrain(knock on wood).

You're Bronco is exactly the reason I suggested possibly going with a 331 stroker. From what I saw, you're Bronco is no slouch at all. That thing sounds mean and runs like it too. I heard something about blowing past a cattle crossing at 93 mph. Philo runs a 302 with a 5-speed and it has plenty of power as well.

The 306 (302 based with .030 over) in my Mustang is pushing well over 400 foot pounds of torque and will outright leave my stock 351 in the dust if it was in another Bronco. My Mustang is built as a drag car that's "street-able".. the torque band is what gets it off the line fast and it's got plenty of torque and it's not even geared low (3.23 gears) but does have a high stall torque convertor.

I wouldn't hesitate to build a 331/347 stroker for a Bronco since those motors like to rev which makes it a lot more fun to drive off-road.

[AussieRod]

A 302 based 347 stroker will work within the factory intake, electronics, drivetrain, etc whereas a 408 would start to need some serious beef in the drivetrain, as well as electronics work to make EFI trouble free. PM Seattle FSB, he has already been and done the 408 conversion, and can fill you in on whats needed to make it all work. I'm going 347/302 package when its time to upgrade my powerplant, light weight, compact and with alloy heads, lighter than the original alloy head six it replaced

[BDKW1]

I'm not a fan of the 347's. Rod ratio sucks, wrist pin hieght sucks. 3.25 stroke is all the more I would go in a 302 block. Spending the coin for a real block and going with a 4.125 bore would get you the 347 and be way more reliable. Also the bigger bore lets you open up the chambers a little more unshrouding the intake.

[gunit]

My engine builder warned me away from the 347. In his opinion because of the rod angles the life expectancy of the 347 was a lot less than the 331. He said in his experience the 331 would last as long as the 302 but with the 347 life was limited with sustained relatively high rpm operation.

[AussieRod]

My engine builder warned me away from the 347. In his opinion because of the rod angles the life expectancy of the 347 was a lot less than the 331. He said in his experience the 331 would last as long as the 302 but with the 347 life was limited with sustained relatively high rpm operation.

A lot of rod ratio talk is BS. Rod ratios become important over 6000 rpm, under that, a short rod is better for speed off TDC, it helps cylinder filling thru the mid range. I'm interested in torque and a compact engine package. If the right length rod is used (to keep the oil ring out of the pin hole) and respecting the limits of the package, life expectancy is no different. If money was no concern, rather than buy a FRPP block I will go 5.0 Coyote and forget the traditional small block..... all alloy, 414 HP, 7000 safe RPM. EFI and great fuel economy

[hobbyturnedobsession]

Thats what id do is the coyote

[economig]

Just get whatever works...

ImageUploadedByTapatalk1354203002.392540.jpg (174.49 KiB) Viewed 4205 times

[cs_drums]

I started research awhile back on the stroker subject and everything was based on high dollar build with mas conversions. I am now to broke and tired spending time and money. My questions are-

Could you stoke out a stock motor with stock speed density and yeild some gains in tq and hp?

I know speed density limits cam. heads and fuel system upgrades but could it handle more displacement?

How differnt is the SD set up in similar year 460s? Could you work with parts from that system to make a smog legal stroker set up?

I am sick of worrying about the smog man and I don't have the $$ to buy my desert property yet ; )

[robertcrav]

If you were set on 347, you could probably find something similar to the DSS Racing Engines SX Piston

However, I'm still gonna say the 408 will make the same power at lower RPM than the 331/347 at high RPM...

That being said, what's more detrimental - wringing out a 331/347 at the high end or using the meat of a 408 at lower RPM?

damn image link not working....

[Andy Jones]

Just get whatever works...

ImageUploadedByTapatalk1354203002.392540.jpg

Best post yet!! I'm gonna do the 347 F.I motor with a Danzio tune.

[Agui-E7TE]

If you were set on 347, you could probably find something similar to the DSS Racing Engines SX Piston

However, I'm still gonna say the 408 will make the same power at lower RPM than the 331/347 at high RPM...

That being said, what's more detrimental - wringing out a 331/347 at the high end or using the meat of a 408 at lower RPM?

damn image link not working....

That's the problem that sometimes the lower end grunt only goes so far when you're driving like Gun-It does which I think is safe to say that we'd all like to go that fast. I'd certainly like to have much more power when I'm up to speed and the 351 isn't really that great at doing that. The funny thing is most of us have the 351 so we judge the 302 based on the 351's performance without trying out a 302. I've always found the 302 to have way more power available through the RPM range than 351 when hauling the mail. A lot of folks on here have said when stroking a 351, it's best to stick to a 393 stroker as opposed to the 408. Like Rod said, with a 331/347 stroker, you can still use most of your efi components to get it to run right whereas a 408 would require some serious tuning with bigger injectors, fuel pump, fuel rails, fuel lines, regulator, and possibly even a lightning mass air meter.