stroker, yes or no?

[bubbaflaat]

Hey guys, i'm going to have my engine built here in a week or so, i'm just wondering if alot of people are doing the stroker crank or no? I haven't seen too many threads on them or anything so i was wondering if anyone has dynoed one or what have you. Its only going to be a extra hundred dollars or so but i still want the engine to rev nicely and be reliable. I'm still going to be running a ported eaton with the engine setup for now. But i figure you can't go wrong with more displacement. Thanks!

 

[forcefedcobra]

Hey guys, i'm going to have my engine built here in a week or so, i'm just wondering if alot of people are doing the stroker crank or no? I haven't seen too many threads on them or anything so i was wondering if anyone has dynoed one or what have you. Its only going to be a extra hundred dollars or so but i still want the engine to rev nicely and be reliable. I'm still going to be running a ported eaton with the engine setup for now. But i figure you can't go wrong with more displacement. Thanks!

from the few people that I have spoken to I would say no. bore 20 or 30 over yes.

 

[wy3134]

im relatively new to engine building, but why would you stroke a supercharged motor? i could understand going to the 5.4 but otherwise just boring to 20 or 30 over seems the most sense... im curious on this as well so please correct me on what im wrong (wanting to learn why or why not)... subscribing

 

[Posi]

Unless Boss 330 racing built an engine for me I'd just stay with stock stroke. You can get all the power you need out of 281 cubes.

 

[04MystiCobra]

I think it depends on what you want/ expect from your car. Some things cant be changed once you put it all together. If I can swing it I'll go at least to a 302 if not a 324. Combined with a big blower, ported heads and GT cams it should make for a deadly combo and make tons of power all over the rpm band.

 

[zeus201]

My motor has been stroked out (302) and with just a 8lb lower and stock upper, full exhaust the car was able to put down right around ~ 480 rwhp / ~ 520 rwtq. Eaton is nonported too which I think are decent #'s without having a port. The car rev's nicely and it's reliable, but seems to run out of steam around 6K RPM because of the 8lb...I think.

I'm not quite sure if #'s can be attributed to stroker kit, but I'd like to think so. :shrug:

 

[bubbaflaat]

thanks for the input... I guess not alot of people have them? I'd really like to see some dyno graphs for a before and after stroker. But the bad thing is when people get into the bottom end they almost always do other things too so its hard to say the actual hp and tq gain.

 

[TT04Cobra]

I've heard that the piston skirt comes too far out of the cylinder and puts alot of stress on the cylinder wall and damages over time.

 

[Stalker27]

I'm all for it. If it's going to cost you just a littl more I say go for it.

If you get the chance pick up the MM&FF magazine the August issue. In there they did a bunch of dyno's with headers, cam's, stroking,& Ported cylinder heads.

To answer your question when they stroked the 4.6 to a 5.0 it went from around 401 peak hp on the 4.6 to around 450 peak hp give or take & the torque jumped considerably. It went from around 355 of TQ with the 4.6 to very close to 400hp. I'm guessing at it since they didn't put any numbers in just a dyno graph. Now who wouldn't like all that extra TQ without increasing boost. If you can make more power without having to raise boost then that means your motor is much more effecient at what it's doing. Not to mention the motor will live much longer

It's as simple as this. Bigger motors make more power & they can accomplish this at a lower engine speed & don't have to rev as high which makes it perfect for the street.

For the sake of argument, let's say that the head flow limits NA power production to 450 hp at 7,000rpm on out hypothetical 4.6 motor. Assuming that 450 hp is the absolute power limit on the 4.6, we then decide to increase the displacement. Using basic math skills, we see that our 450 hp 4.6 achieved a specific output of roughly 98 hp per liter.

If we apply that number to a 5.0L combination we see that the new peak output should jump to 490 hp. The two fold benefit of having the larger displacement is that we achieve both a higher average power output (more power throughout the rev range) & a potentially higher peak number based on the combination of specific output & engine speed.

Where the 4.6 needed to rev to 7,000rpm to achieve peak power the larger displacement 5.0 stroker motor will make it's peak power at a lower engine speed. This drop in engine speed will reduce the airflow requirement to reach a given power output & make it more streetable. Thus a larger motor is able to make more power at a lower engine speed if limited by airflow.

Now, all of these dyno's including the one i mentioned was done on a NA 4.6 two valve. Now given what it made on the two valve immagine putting a KB blower on it

 

[forcefedcobra]

I'm all for it. If it's going to cost you just a littl more I say go for it.

If you get the chance pick up the MM&FF magazine the August issue. In there they did a bunch of dyno's with headers, cam's, stroking,& Ported cylinder heads.

To answer your question when they stroked the 4.6 to a 5.0 it went from around 401 peak hp on the 4.6 to around 450 peak hp give or take & the torque jumped considerably. It went from around 355 of TQ with the 4.6 to very close to 400hp. I'm guessing at it since they didn't put any numbers in just a dyno graph. Now who wouldn't like all that extra TQ without increasing boost. If you can make more power without having to raise boost then that means your motor is much more effecient at what it's doing. Not to mention the motor will live much longer

It's as simple as this. Bigger motors make more power & they can accomplish this at a lower engine speed & don't have to rev as high which makes it perfect for the street.

For the sake of argument, let's say that the head flow limits NA power production to 450 hp at 7,000rpm on out hypothetical 4.6 motor. Assuming that 450 hp is the absolute power limit on the 4.6, we then decide to increase the displacement. Using basic math skills, we see that our 450 hp 4.6 achieved a specific output of roughly 98 hp per liter.

If we apply that number to a 5.0L combination we see that the new peak output should jump to 490 hp. The two fold benefit of having the larger displacement is that we achieve both a higher average power output (more power throughout the rev range) & a potentially higher peak number based on the combination of specific output & engine speed.

Where the 4.6 needed to rev to 7,000rpm to achieve peak power the larger displacement 5.0 stroker motor will make it's peak power at a lower engine speed. This drop in engine speed will reduce the airflow requirement to reach a given power output & make it more streetable. Thus a larger motor is able to make more power at a lower engine speed if limited by airflow.

Now, all of these dyno's including the one i mentioned was done on a NA 4.6 two valve. Now given what it made on the two valve immagine putting a KB blower on it

I agree with that but displacement can be achieved without stroking a 4.6 and like someone said before the main concern that some express is the increased amount of piston skirt being exposed at the bottom of the cylinder due to the use of a stroker crank.

 

[Stalker27]

^^^ Yeah i read that & agree BUT you have to look at the MANY 347's and 408's. They all do that but you very rarley here about anything catastrophic happening.

 

[Finaltheorem47]

stroke it, you will be okay. All this piston skirt stuff is just speculation. It probably happens as much as someone snaps a rod. Theres no replacement for displacement.

 

[TwinTurbo4vGT]

dont stroke it, i have heard from too many people of their engines failing because of stroker kits. They are nowhere near as reliable as a standard stroke car. Leave it, 100$ saved now can cost you thousands down the road..

 

[blackvenom77]

Also doesn't it take the engine longer to rev if it's stroked out?

 

[Stalker27]

^^^ Not to criticize but did you not read my post?? It clearly states that stroker motors DO NOT have to rev as high as the 4.6.

Also it makes peak hp & tq at lower rpm's

 

[EvilTwins]

There have been documented failures with regards to stroking these engines. I read through a thread a little while ago that had great pics of horrible cylinder wall wear due to the use of a stroker kit. The bottoms of the bores had very significant scoring and the engine was toast.

I don't like the fact that piston wear will increase with a stroker because piston speed is drastically increased. Although peak torque will most definitely move lower in the rpm range, with a good breathing engine you still want to at least rev it to 6000.

 

[GodStang]

Been Stroked for three years and no problems. Is it worth the extra money??? No but hey its just money. When I was running the 2.2L I was making over 500rwtq at 1800rpms @ 17psi with a max being 640rwtq @ 17psi. So there was TQ down low.

 

[Mike K]

Been Stroked for three years and no problems. Is it worth the extra money??? No but hey its just money. When I was running the 2.2L I was making over 500rwtq at 1800rpms @ 17psi with a max being 640rwtq @ 17psi. So there was TQ down low.

What kind of numbers are you making now with the 2.8?

 

[Jroc]

I vote yes for stroker motor. One of those 324's would be badass.

 

[blackvenom77]

^^^ Not to criticize but did you not read my post?? It clearly states that stroker motors DO NOT have to rev as high as the 4.6.

Also it makes peak hp & tq at lower rpm's

Sorry must of missed that. SlowSVT said otherwise and he seems to know alot about these cars so I don't know what to believe now. :shrug: