331 Stroker

[Holik95]

I'm already making 300 rwhp right now. So I'm only going to pick 5 rwhp with a 331.

 

[Swarzkopf]

I give up on this thread. If there is a moderator out there, please lock it down. We have gone from discussion to nit picking sentence structure, and its no longer beneficial.

I agree. The 94-95 section is usually so mellow too..hmmm.

 

[Grn92LX]

I'm already making 300 rwhp right now. So I'm only going to pick 5 rwhp with a 331.

If you put the induction parts from your 302 on a 331 or a 347 you aren't going to gain too much at the peak. I can see maybe 315rwhp based off what I seen on the net from other mild strokers with 302 parts. Your low and mid range will increase though. A cam swap would do you wonders! You shouldn't have a problem hitting 350rwhp with a cam swap and maybe a bigger exhaust. Let me know if you need help picking parts.

 

[Holik95]

What kind of cam do you recommend? What do you mean by bigger exhaust? Keep in mind this car is a daily driver and has to pass an emission test.

 

[Grn92LX]

I would recommend a custom grind cam from www.flowtechinduction.com (FTI) along with matching valve springs. By larger exhaust I mean an 1 3/4" longtube with a 3" mid pipe. The 2.5" cat back will be fine. If you're serious, email Ed @ FTI and talk over your goals. Ed will tell you the same thing to go 347 but regardless whether 331 or 347, you need a new cam at the very minimum.

 

[5spd GT]

A 331 and 347 are both "mild" strokers. Little difference...but it sounds cooler to say 347.

Black95GTS - You specifically said the only unique thing about a 331 is that it is uniquely slow...you said "the" and not "that". We all know what you were intending with the heat of the moment response.

I'm pretty sure no one said it would "significantly" reduce the power output on a 347 with the rod ratio. So who is nitpicking?

Daily Driver is key in "picking parts"...

It is harder to guess rwhp numbers when you don't know the tranny, accessories had or not had, custom cam specs, emissions setup,...so why do some say "you should be seeing higher numbers", etc...? It just doesn't make sense...

 

[Pokageek]

"KillerCanary - I'm quite sure that Pokageek didn't say a 331 was faster nor wanted to prove it..."

That's right. My comments were of a joking nature mainly.


As to the rest...NM...

 

[Green 94 5.0]

there are so many variables that you cant even compare. everything from the h/c/i setup, to the comp. ratio, to the tuning, to the weight of the internals can all effect power output. i highly doubt that the rod ratio effects power negatively in a noticeable way. everything being equal, the 347 will make more power than the 331. will it be a huge difference? i doubt it. if i was planning on going n/a with the new motor, it would have been a 347 without a doubt. i chose the 331 because being that im looking at 450-475whp, which is already painfully close to the stock blocks limits i wanted the rotating assembly that would put the least amount of undue stress on the block. i couldnt justify the added risk from the sidewall loading for the 16ci. regardless though both are tried and true strokers and both will net good gains over a 302. we are all here for the same reason, so lets not forget that.

 

[Blk91stang]

I can back up B&B's findings, I too have seen very little difference between a 331/347 with similar components, even the curves were very similar.

I determine what would be best for the customer by the ultimate use of the car, auto or 5spd, weight, the future and as always budget.


The 331 vs 347 thing has been argued about for years, you can build a 347 different to take advantage of the slightly lighter piston (when using a 5.4" rod) and small increase in stroke.

This is basically what I was trying to say, except I came out as an ignorant ***hole who only threw fuel in the fire.

Thanks Rick.

 

[Blk91stang]

there are so many variables that you cant even compare. everything from the h/c/i setup, to the comp. ratio, to the tuning, to the weight of the internals can all effect power output. i highly doubt that the rod ratio effects power negatively in a noticeable way. everything being equal, the 347 will make more power than the 331. will it be a huge difference? i doubt it. if i was planning on going n/a with the new motor, it would have been a 347 without a doubt. i chose the 331 because being that im looking at 450-475whp, which is already painfully close to the stock blocks limits i wanted the rotating assembly that would put the least amount of undue stress on the block. i couldnt justify the added risk from the sidewall loading for the 16ci. regardless though both are tried and true strokers and both will net good gains over a 302. we are all here for the same reason, so lets not forget that.

I am in the same boat as you. Even if there was no sideloading, the reduction in horsepower from the smaller cubes is worth it to keep the block in 1 piece.

 

[final5-0]

This is basically what I was trying to say, except I came out as an ignorant ***hole who only threw fuel in the fire.

Thanks Rick.

Matt

I can only speak for myself

I did not see you in that way at all

There's many variables to an engine other than displacement.

The above is a direct paste from one of your earilier posts and those words don't look ignorant to me

I think some in this thread are mixing applications here.

331/347 combos for totally strip or where the focus is more on the strip than the street can be as you and Rick have pointed out. All kinds of things could be happening where it would be difficult to have an apples to apples comparison when talking about peak dyno results ... again ... as you have pointed out Matt

However ... when talking about just a general all around or non specific built combo ... for a street oriented application. I don't think it is unreasonable to say you should see some extra performance (although it would not be a huge amount) from the cubes of the larger motor.

331's are not wrong or bad or ineffective IMHO

I've tried to keep my participation in this thread neither offsensive or defensive but then again ... how others perceive your comments is beyond your control.

Rick was kind to come in here and give his findings and since he is a Pro ...

I feel for me ... I have to keep an open mind about what he said

All my life ... I've seen cubes give more of the kind of performane I want for a STREET car and thats how I will sum up my thoughts.

Sorry if you thought I had my six guns pointing at you Matt
It was not my intent to even draw em

Grady

 

[Blk91stang]

Matt

I can only speak for myself

I did not see you in that way at all

There's many variables to an engine other than displacement.

The above is a direct paste from one of your earilier posts and those words don't look ignorant to me

I think some in this thread are mixing applications here.

331/347 combos for totally strip or where the focus is more on the strip than the street can be as you and Rick have pointed out. All kinds of things could be happening where it would be difficult to have an apples to apples comparison when talking about peak dyno results ... again ... as you have pointed out Matt

However ... when talking about just a general all around or non specific built combo ... for a street oriented application. I don't think it is unreasonable to say you should see some extra performance (although it would not be a huge amount) from the cubes of the larger motor.

331's are not wrong or bad or ineffective IMHO

I've tried to keep my participation in this thread neither offsensive or defensive but then again ... how others perceive your comments is beyond your control.

Rick was kind to come in here and give his findings and since he is a Pro ...

I feel for me ... I have to keep an open mind about what he said

All my life ... I've seen cubes give more of the kind of performane I want for a STREET car and thats how I will sum up my thoughts.

Sorry if you thought I had my six guns pointing at you Matt
It was not my intent to even draw em

Grady

No worries. I just got a little caught up OT:, I'm turning 21 at midnight tonight so I thought the cheers was appropriate ) . I can tell you that if I could afford a Dart Block right now, a 347 would end up inside of it despite my arguments .

 

[Rick 91GT]

No worries. I just got a little caught up OT:, I'm turning 21 at midnight tonight so I thought the cheers was appropriate ) . I can tell you that if I could afford a Dart Block right now, a 347 would end up inside of it despite my arguments .

 

[Killercanary]

No worries. I just got a little caught up OT:, I'm turning 21 at midnight tonight so I thought the cheers was appropriate ) . I can tell you that if I could afford a Dart Block right now, a 347 would end up inside of it despite my arguments .

If you had a dart block, why not go for a 363ci? Its just a 4.125 bore instead of the standard .030" overbore.

 

[Rick 91GT]

If you had a dart block, why not go for a 363ci? Its just a 4.125 bore instead of the standard .030" overbore.

My thoughts exactly, I am building more and more BIG bore 3.25" stroke 347ci or 3.4" stroke 363ci motors. The largest issues there are the off the shelf pistons availabel when you are talking about boosted motors. Probe is working on some, I have a set here that I was looking at but they are a .912" pin. My last set were semi customs from Diamond, 21+cc dish, 3.4" stroke.

If you use the correct head you can take advantage of the large bore and make great power

 

[Pokageek]

If you had a dart block, why not go for a 363ci? Its just a 4.125 bore instead of the standard .030" overbore.

Because then the rods will REALLY hit the block and slow it down even more. I'M JOKING!

 

[divit250r]

Piston question...

I've seen several pics of 347 builds and all versions had compression heights on the pistons that put the pin right through the oil control ring. Is this not as much of a problem as it used to be for street engines? I'm not trying to start a war, just honestly curious about this.

Scott

 

[Pokageek]

Bad build or manufacturer error?

 

[Black95GTS]

I've seen several pics of 347 builds and all versions had compression heights on the pistons that put the pin right through the oil control ring. Is this not as much of a problem as it used to be for street engines? I'm not trying to start a war, just honestly curious about this.

Scott

Yes, that is indeed an old problem, and as such created the rumor that 347 were oil burners.

What has evolved since then are two solutions to that problem (which is the the 5.400 inch rod)

1 - Builders will use oil rail spacers as work-arounds.

2 - A shorter 5.315 rod is used. The taller compression height avoids the issue.

Adam

 

[Yobi1Kanobi]

Another fix for the oil burning problem is standard rings. In the earlier years they were building 347 with low tension ring to free up some HP as you could on a 302 but with the interjecting oil pin that cause early oil burning.