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4.15 stroke vs 4.25 stroke what are the pros and cons

Posted By: torqueaddict

4.15 stroke vs 4.25 stroke what are the pros and cons - 07/10/12 06:21 AM

When doing a 440 stroker what are the pros and cons of each, i.e. clearance issues what gives the most hp and torque what is a better street motor. Im just looking for personal experience and preferences.
Posted By: DirectSubjection

Re: 4.15 stroke vs 4.25 stroke what are the pros and cons - 07/10/12 06:44 AM

Depends on the components used, set-up etc. A broad statement overall would be something like:


A shorter stroke may feel more "snappy" and allow for faster and higher revving.

A longer stroke may provide more torque and thump feel.
Posted By: DPelletier

Re: 4.15 stroke vs 4.25 stroke what are the pros and cons - 07/10/12 04:03 PM

The larger engine will make more power.

as far as the bore vs. stroke thing if everything else is equal, it makes no appreciable difference.


Dave
Posted By: Pyper70

Re: 4.15 stroke vs 4.25 stroke what are the pros and cons - 07/10/12 07:04 PM

4.15 you can use mostly all general components....when you hit a 4.25 stroke you get into issues like external oiling, counterbalances smacking into things stuff like that
Posted By: JohnRR

Re: 4.15 stroke vs 4.25 stroke what are the pros and cons - 07/10/12 07:06 PM

Quote:

4.15 you can use mostly all general components....when you hit a 4.25 stroke you get into issues like external oiling, counterbalances smacking into things stuff like that



4.25 stroke cranks are 99.99% 2.2 big end, not chrysler big end, so this isn't an issue, even in a low deck.
Posted By: dynamite

Re: 4.15 stroke vs 4.25 stroke what are the pros and cons - 07/10/12 07:07 PM

Kinda what I said last week

Attached picture 7286077-STP60357.JPG
Posted By: torqueaddict

Re: 4.15 stroke vs 4.25 stroke what are the pros and cons - 07/10/12 07:22 PM

I am really debating on what I am gonna do. I already have most of the components for the 4.15 stroke. I had to send the pistons back and now if I dont pay the more money I cant get the pistons needed. Not to mention when they get here I have to pay for balancing. If I get the refund then I can buy the 440 source 512 kit(what I should done fro the start.I really dont know what to do.
Posted By: Dean_Kuzluzski

Re: 4.15 stroke vs 4.25 stroke what are the pros and cons - 07/10/12 07:32 PM

Quote:

I am really debating on what I am gonna do. I already have most of the components for the 4.15 stroke. .................... If I get the refund ..................I really dont know what to do.



If they WILL give you a refund and NOT a credit you may have a choice.

A few more cubes isn't worth the stress. Build what you have and learn from it for the next shortblock.
Posted By: 383man

Re: 4.15 stroke vs 4.25 stroke what are the pros and cons - 07/10/12 09:20 PM

All I can tell you is I am very pleased with my 4.15 crank 440 stroker (493) as it has run very good for me and I have not done any real tuning yet. Everything fits without any issue's. Sure bigger is always better but the 4.15 stroker does run good. Ron
Posted By: torqueaddict

Re: 4.15 stroke vs 4.25 stroke what are the pros and cons - 07/10/12 10:10 PM

Quote:

Quote:

I am really debating on what I am gonna do. I already have most of the components for the 4.15 stroke. .................... If I get the refund ..................I really dont know what to do.



If they WILL give you a refund and NOT a credit you may have a choice.

A few more cubes isn't worth the stress. Build what you have and learn from it for the next shortblock.




I think your right but I am just really upset about how hughes has treated me and acted as if it were my fault. They will refund me at a 400 dollar restocking fee, that means I am only gonna get around 1600 back. If I keep the it I have to pay them 200 dollars for them to send me the correct pistons and 250 to balance it from my local machine shop. Or I can take my money and go to 440source. If I go to 440source at least I can get a custom kit that works put of the box.
Posted By: DARTH V8Я

Re: 4.15 stroke vs 4.25 stroke what are the pros and cons - 07/10/12 10:28 PM

4 1/4" stroke and more I really don't like.. it puts the oil rings WAY to close to the pin, or OVER the wrist pin. No way I'd be convinced it would last in a REAL street engine. JMHO.
Posted By: Dean_Kuzluzski

Re: 4.15 stroke vs 4.25 stroke what are the pros and cons - 07/10/12 11:52 PM

Quote:

If I go to 440source at least I can get a custom kit that works put of the box.



OK, but personally, I wouldn't install ANY kit w/o checking the machined tolerances myself or by a trusted local machinist.
Posted By: OhioMopar

Re: 4.15 stroke vs 4.25 stroke what are the pros and cons - 07/10/12 11:58 PM

Quote:

Quote:

Quote:

I am really debating on what I am gonna do. I already have most of the components for the 4.15 stroke. .................... If I get the refund ..................I really dont know what to do.



If they WILL give you a refund and NOT a credit you may have a choice.

A few more cubes isn't worth the stress. Build what you have and learn from it for the next shortblock.




I think your right but I am just really upset about how hughes has treated me and acted as if it were my fault. They will refund me at a 400 dollar restocking fee, that means I am only gonna get around 1600 back. If I keep the it I have to pay them 200 dollars for them to send me the correct pistons and 250 to balance it from my local machine shop. Or I can take my money and go to 440source. If I go to 440source at least I can get a custom kit that works put of the box.


I thought that was Hughes m.o.? Treating people like they were idiots when they screwed something up? I could be wrong. Thought they were on the same list as Jim's and the guy from New York that got banned. Fuelinjectedfish?
Nothing to add to the topic, I have wondered the same thing myself when trying to decide what I wanted to put in my R/T.
Posted By: BSB67

Re: 4.15 stroke vs 4.25 stroke what are the pros and cons - 07/11/12 12:17 AM

Quote:

4 1/4" stroke and more I really don't like.. it puts the oil rings WAY to close to the pin, .... JMHO.



Curious, exactly what dimension between the oil ring and pin is too small?

I prefer the 4.25 arm w/ 2.2 big end, 7.1 rod and .990 pin for the following reasons: 1)Bigger, 2)lighter piston, 3)better rod/throw ratio, 4)lighter rotating. And there is no down side.

But, in the end, it likely makes no measurable difference to us street guys.
Posted By: CHAPPER

Re: 4.15 stroke vs 4.25 stroke what are the pros and cons - 07/11/12 12:25 AM

4.15 in a factory block with billet caps.....4.25 in after market block with all the improvements.
Posted By: gregsdart

Re: 4.15 stroke vs 4.25 stroke what are the pros and cons - 07/11/12 01:49 AM


Consider the size difference by percentage. Not much between 4.15 and 4.25. If there is no problem switching go with the longer stroke. Or longer, if it will clear and still allow an internal oil pickup, which I assume you want to keep.
After having built a 535 cube stock block and heads motor, IMHO bigger is better. That motor would run low tens in a 3400 lb car shifting at 5700 rpm.
You should easily be able to fit a 4.25 stroke deal in a stock block with a 2.2 rod bearing. The other consideration is which size bearing to run. The BBC 2.2 with .990 piston pins is the best choice because it reduces rotating weight. All the parts get lighter, crank, rods, pistons!
Posted By: quickd100

Re: 4.15 stroke vs 4.25 stroke what are the pros and cons - 07/11/12 02:10 AM

If you have a choice always go with displacement. If nothing else it should make more torque and do everything better at a lower rpm. Engines like low rpm, things last longer, rods have a lower chance of making a break for it and exiting the block. My 605 make 818 ftlbs of torque at 4800rpm and runs on 89.5 octane fuel. Take the displacement. Dave
Posted By: JohnRR

Re: 4.15 stroke vs 4.25 stroke what are the pros and cons - 07/11/12 05:36 AM

Quote:

Quote:

Quote:

I am really debating on what I am gonna do. I already have most of the components for the 4.15 stroke. .................... If I get the refund ..................I really dont know what to do.



If they WILL give you a refund and NOT a credit you may have a choice.

A few more cubes isn't worth the stress. Build what you have and learn from it for the next shortblock.




I think your right but I am just really upset about how hughes has treated me and acted as if it were my fault. They will refund me at a 400 dollar restocking fee, that means I am only gonna get around 1600 back. If I keep the it I have to pay them 200 dollars for them to send me the correct pistons and 250 to balance it from my local machine shop. Or I can take my money and go to 440source. If I go to 440source at least I can get a custom kit that works put of the box.



Did you tell Hughes exactly what you were looking for? Did they offer you, or tell you, that there was a dish piston option?

I've had my share of issues with Dave , but from reading your posts on this whole build subject I really don't think Hughes is totally at fault here.

Do you really think that a cheap charlies chinese junk stroker kit, from anyone, is going to be good to go out of the box ? ...
Posted By: 451Mopar

Re: 4.15 stroke vs 4.25 stroke what are the pros and cons - 07/11/12 09:52 AM

I built a stroked 400 with the 4.15" stroke crank , 6.76" rods, and flat tops (499cid @ 4.375" bore.) With the 75cc Edel-broke Victors, Compression is 12.4:1.
Everything fit, only needed to clearance the oil pump pickup boss. The machine shop I used "re-balanced" the 440 source balanced assembly, and I think they messed up the balance. I'm going to have it re-checked now that the engine is out because of the broken cylinder head.

I also just built a stroked 440 (only 0.030 over or 4.350") with the 4.25" stroke, 7.1" rods, and 17cc dished pistons with 84cc stealth heads for about 10.3:1 compression, and 505 cid (I think 512 is with a 4.375" bore size.) No clearance issues, just the oil pump pickup boss. FWIW, both engines are using 1/2" internal oil pickup tubes.
I bought a scale and rod balancing fixture and verified the balance weights were the same as what 440 source had on their balance sheet. My average Reciprocaring weight (piston, pin, locks, rings, and pin end of rod measured within 1.39 gram. The Rotating end weight was within 0.71 gram. So, I did not re-balance the crank, and this engine runs smooth. A few rods had tight pin bosses, and one had the rod bearing "notch" slightly out of place where it positioned the bearing too close to the crank fillet so there was almost no rod side clearance. This was found during mockup and corrected by chamfering the bearing slightly.
All the main and rod oil clearances were good, around 0.002".

No issues with ring packs or anything like that.
Windage tray selection for clearance of the crank and oil pan may be a consideration? The 440 source stroker windage trays are too deep for a stock or reproduction "Hemi" oil pan, but do fit most race oil pans.
Posted By: Dragula

Re: 4.15 stroke vs 4.25 stroke what are the pros and cons - 07/11/12 12:57 PM

I have run the 4.15" stroked RB's and Hemi's, and currently I am running a 4.25 stroked RB, and that thing is an animal. We only shift it at 6300, and it has alread gone 10.10 at 134mph on 93 octane!

Go with the stroke if you can. Having all that torque is awesome.
Posted By: torqueaddict

Re: 4.15 stroke vs 4.25 stroke what are the pros and cons - 07/11/12 03:17 PM

Quote:

Quote:

Quote:

Quote:

I am really debating on what I am gonna do. I already have most of the components for the 4.15 stroke. .................... If I get the refund ..................I really dont know what to do.



If they WILL give you a refund and NOT a credit you may have a choice.

A few more cubes isn't worth the stress. Build what you have and learn from it for the next shortblock.




I think your right but I am just really upset about how hughes has treated me and acted as if it were my fault. They will refund me at a 400 dollar restocking fee, that means I am only gonna get around 1600 back. If I keep the it I have to pay them 200 dollars for them to send me the correct pistons and 250 to balance it from my local machine shop. Or I can take my money and go to 440source. If I go to 440source at least I can get a custom kit that works put of the box.



Did you tell Hughes exactly what you were looking for? Did they offer you, or tell you, that there was a dish piston option?

I've had my share of issues with Dave , but from reading your posts on this whole build subject I really don't think Hughes is totally at fault here.

Do you really think that a cheap charlies chinese junk stroker kit, from anyone, is going to be good to go out of the box ? ...



Yes I was clear as day in terms of what I wanted from hughes. The pistons needed to give me the right compression were not a regular item for them. They had to order them, 440source a more diverse piston selection. Rather than tell me hey we dont have the parts you need sir. They sold me a kit that was not good for a pumped gas street car. Thats what happened.
Posted By: JohnRR

Re: 4.15 stroke vs 4.25 stroke what are the pros and cons - 07/11/12 04:38 PM

Quote:


Yes I was clear as day in terms of what I wanted from hughes. The pistons needed to give me the right compression were not a regular item for them. They had to order them, 440source a more diverse piston selection. Rather than tell me hey we dont have the parts you need sir. They sold me a kit that was not good for a pumped gas street car. Thats what happened.



Did they tell you that about the pistons up front or did this info come out AFTER you found out yourr compression was going to be too high ??

Oh , by the by , We built a 12.2 compression 470" engine that ran on 91 octane fuel ... but that's over and above a cheap charlies discount chinese junk build budget ...
Posted By: torqueaddict

Re: 4.15 stroke vs 4.25 stroke what are the pros and cons - 07/11/12 05:13 PM

It came after, that never came up until I had the kit I could not use. I am still toiling over with sending this kit back or just paying the extra money. If I send it back and get 440source kit I think I will get the 512 kit. If there is really no benefit of getting the bigger kit I think I will just keep the one I have. Its just a little more simple this way me thinks.
Posted By: JohnRR

Re: 4.15 stroke vs 4.25 stroke what are the pros and cons - 07/11/12 05:47 PM

I would just get the pistons and use what you have, it will be cheaper and seriously you won't notice the difference all that much with the power level you are shooting for.

Have you figured out the compression yet ? You could get a custom cam that will bleed off cylinder pressure and make your compression ratio pump gas friendly , that would be cheaper than getting the new pistons .
Posted By: torqueaddict

Re: 4.15 stroke vs 4.25 stroke what are the pros and cons - 07/11/12 06:49 PM

If I were to use the original pistons it would be 11.5, if I get the new pistons it would be 10.5 If I get the big cam I will end up spending alot of money on making my stealth heads useable. New springs retainers and locks the whole sort. I dont really want that radical a cam anyway. I kinda want a sleeper for my car. I really want to surprise people.
Posted By: JohnRR

Re: 4.15 stroke vs 4.25 stroke what are the pros and cons - 07/11/12 07:20 PM

Quote:

If I were to use the original pistons it would be 11.5, if I get the new pistons it would be 10.5 If I get the big cam I will end up spending alot of money on making my stealth heads useable. New springs retainers and locks the whole sort. I dont really want that radical a cam anyway. I kinda want a sleeper for my car. I really want to surprise people.



Oh, so you are HOPING the heads are going to be ready to run out of the box ???
Posted By: Hughes

Re: 4.15 stroke vs 4.25 stroke what are the pros and cons - 07/11/12 07:21 PM

Anthony, You are not telling these guys the entire story. The stroker kit I sold you would have ended up being approximatley 11.3:1 compression ratio. A 496 cubic inch stroker, along with a set of 85cc Stealth heads and our HEH5055Bl cam would net out at approximately 185 pounds of cranking cylinder pressure. This will easily run on pump gas without any detonation. Now, because of peer pressure from people who have nothing invested in your car (money like you or reputation like me)you are afraid to build anything over 10 or 10.5:1. I have explained to you multiple times in a calm and respectful manner, that cranking cylinder pressure is what you really care about, not just the compression ratio. 2 weeks ago you told me that you wanted pistons that would give you closer to 10.5:1 no matter what. I gave in and agreed to take back the pistons you have and get you a set of new pistons with the dish in them you want. I DID tell you that they would cost more and that this would require balancing the new pistons and then making up a new bobweight and balaning the crank. You agreed to all of this. Now, the pistons are here and you are getting cold feet again about the compression and you don't want to pay for the pistons or the freight etc... I understand how frustrating this is for you which is why I have spent, literally, hours on the phone with you teaching and explaining how I helped you choose the parts. This is the difference between us and someplace like Summit or Jegs where you just order parts online and hope it all works. There are a lot of good reputable engine builders out there who can confirm that 185psi cranking cylinder pressure will work fine for you. JohnRR is giving you good advice. Put it together and enjoy it. Now, if your whole problem is that you have changed your mind and now want a 4.250" stroke instead of a 4.150 stroke...that is another story. We also spent a lot of time discussing that issue. Like JohnRR said, there really is no difference on a build like yours. With the heads flowing no more than they are and the pump gas compression you won't be able to feel any difference.
I just wanted to clear this up and explain my side of this issue. You being happy when this done is our best advertising. I would not suggest parts that wouldn't give you what you need. You can beleive me or not believe me. That is your choice. I am not going to beg you to build it right. I guess I should have just sold you a 10:1 kit like you first asked for and not worried about how it ran. But that is not how I like to do things. I would rather exceed your goals than see you disappointed.

Attached picture 7287730-HughesEnginesLogowith3small.jpg
Posted By: JohnRR

Re: 4.15 stroke vs 4.25 stroke what are the pros and cons - 07/11/12 07:28 PM

Quote:

Anthony, You are not telling these guys the entire story. The stroker kit I sold you would have ended up bing approximatley 11.3:1 compression ratio. A 496 cubic inch stroker, along with a set of 85cc Stealth heads and our HEH5055Bl cam would net out at approxiamtely 185 pounds of cranking cylinder pressure. This will easily run on pump gas without any detonation. Now, because of peer pressure from people who have nothing invested in your car (money like you or reputation like me)you are afraid to build anything over 10 or 10.5:1. I have explained to you multiple times in a calm and respectful manner, that cranking cylinder pressure is what you really care about, not just the compression ratio. 2 weeks ago you told me that you wanted pistons that would give you closer to 10.5:1 no matter what. I gave in and agreed to take back the pistons you have and get you a set of new pistons with the dish in them you want. I DID tell you that they would cost more and that this would require balancing the new pistons and then making up a new bobweight and balaning the crank. You agreed to all of this. Now, the pistons are here and you are getting cold feet again about the compression and you don;t want to pay for the pistons or the freight etc... I understand how frustrating this is for you which is why I have spent, literally, hours on the phone with you teaching and explaining how I helped you choose the parts. This is the difference between us and someplace like Summit or Jegs where you just order parts online and hope it all works. There are a lot of good reputable engine builders out there who can cnofirm that 185psi cranking cylinder pressure will work fine for you. JohnRR is giving you good advice. Put it together and enjoy it. Now, if your whole problem is that you have changed your mind and now want a 4.250" stroke instead of a 4.150 stroke...that is another story. We also spent a lot of time discussing that issue. Like JohnRR said, there really is no difference on a build like yours. With the heads flowing no more than they are and the pump gas compression you won't be able to feel any difference.
I just wanted to clear this up and explain my side of this issue. You being happy when this done is our best advertising. I would not suggest parts that wouldn't give you what you need. You can beleive me or not believe me. That is your choice. I am notgoing to beg you to build it right. I guess I should have just sold you a 10:1 kit like you first asked for and not worried about how it ran. But that is not how I like to do things. I would rather exceed your goals than see you disappointed.



Good to hear the other side of the story. Very sound reasoning, I don't see the issue other than the up sell of the compression ratio but the cam fixes that ... well I do but that is a subject for a thread in the general section ...

His only problem is he ASSuMEd that the current stealths were 84cc advertised, more like 86 actual ... and they are now advertised as 80cc advertised ... I think 82 is actual ...

Good luck ...
Posted By: AndyF

Re: 4.15 stroke vs 4.25 stroke what are the pros and cons - 07/11/12 08:24 PM

The head gasket can be used to add some volume to reduce the compression. It might kill the quench, but that might not matter on this engine.

The chambers in the heads can also be opened up a bit or the pistons can be shaved a bit.

There are always options. Some of them aren't as pretty as others, but options exist.
Posted By: torqueaddict

Re: 4.15 stroke vs 4.25 stroke what are the pros and cons - 07/11/12 08:48 PM

Quote:

Anthony, You are not telling these guys the entire story. The stroker kit I sold you would have ended up being approximatley 11.3:1 compression ratio. A 496 cubic inch stroker, along with a set of 85cc Stealth heads and our HEH5055Bl cam would net out at approximately 185 pounds of cranking cylinder pressure. This will easily run on pump gas without any detonation. Now, because of peer pressure from people who have nothing invested in your car (money like you or reputation like me)you are afraid to build anything over 10 or 10.5:1. I have explained to you multiple times in a calm and respectful manner, that cranking cylinder pressure is what you really care about, not just the compression ratio. 2 weeks ago you told me that you wanted pistons that would give you closer to 10.5:1 no matter what. I gave in and agreed to take back the pistons you have and get you a set of new pistons with the dish in them you want. I DID tell you that they would cost more and that this would require balancing the new pistons and then making up a new bobweight and balaning the crank. You agreed to all of this. Now, the pistons are here and you are getting cold feet again about the compression and you don't want to pay for the pistons or the freight etc... I understand how frustrating this is for you which is why I have spent, literally, hours on the phone with you teaching and explaining how I helped you choose the parts. This is the difference between us and someplace like Summit or Jegs where you just order parts online and hope it all works. There are a lot of good reputable engine builders out there who can confirm that 185psi cranking cylinder pressure will work fine for you. JohnRR is giving you good advice. Put it together and enjoy it. Now, if your whole problem is that you have changed your mind and now want a 4.250" stroke instead of a 4.150 stroke...that is another story. We also spent a lot of time discussing that issue. Like JohnRR said, there really is no difference on a build like yours. With the heads flowing no more than they are and the pump gas compression you won't be able to feel any difference.
I just wanted to clear this up and explain my side of this issue. You being happy when this done is our best advertising. I would not suggest parts that wouldn't give you what you need. You can beleive me or not believe me. That is your choice. I am not going to beg you to build it right. I guess I should have just sold you a 10:1 kit like you first asked for and not worried about how it ran. But that is not how I like to do things. I would rather exceed your goals than see you disappointed.




Kevin that's nice but when we first started the thing the thi gs I said in my original talk was I wanted a 4.25 stroke kit with dished pistons. In fact my order was put in online and that's what I ordered at first. You told me that what I needed was the flat top pistons and a very radical cam. I told you from the start I wanted a non radical cam. I don't like super lopey idles. If you had told me the things I wanted for
The start were not available or costed extra I would have went elsewhere. You may have meant well but you talked me into something I didnt want from the beginning. The stealth heads I have are supposedly 80cc by the way. The machinist I work with and the guy building my motor tell me that it's not worth the risk. If my motor were to detonate from having to much compression all you will be able to is say your sorry. And I will be up crap creek. Why would I even want to risk it? It's not like you guaranteed it would. It detonate. Why should I take such a big risk just. Because you say so? I k ow you meant well but now no matter what I lose.
Posted By: Triple Threat

Re: 4.15 stroke vs 4.25 stroke what are the pros and cons - 07/11/12 09:05 PM

My stroked small block has 11.3:1 compression and runs on 92 octane pump gas all day long.
Posted By: 3hundred

Re: 4.15 stroke vs 4.25 stroke what are the pros and cons - 07/11/12 09:13 PM

Too many cooks. Pick the one you trust and go with it.

Robert
Posted By: torqueaddict

Re: 4.15 stroke vs 4.25 stroke what are the pros and cons - 07/11/12 09:17 PM

Quote:

My stroked small block has 11.3:1 compression and runs on 92 octane pump gas all day long.




That's another thing I have been tryin to explain to everyone is that here in comifornia they only have 91. That's it. If we do have 92 or 93 somewhere it's nowhere near me.
Posted By: GreenGlow

Re: 4.15 stroke vs 4.25 stroke what are the pros and cons - 07/11/12 10:23 PM

My 512 with stealth heads 11.3:1 compression Xe295 ( I think ) cam runs on 91 octane 34* total timing I add 1 gallon of 110 octane per 4 gallons of gas when I plan to beat on it or maybe I just want to smell the race fuel exhaust.
Posted By: JohnRR

Re: 4.15 stroke vs 4.25 stroke what are the pros and cons - 07/11/12 10:29 PM

Quote:

Too many cooks. Pick the one you trust and go with it.

Robert




WINNER .....
Posted By: 64Post

Re: 4.15 stroke vs 4.25 stroke what are the pros and cons - 07/12/12 12:26 AM

Quote:

Too many crooks. Pick the one you trust and go with it.

Robert



More like it...
Posted By: RUNCHARGER

Re: 4.15 stroke vs 4.25 stroke what are the pros and cons - 07/12/12 12:58 AM

Wow: Listen to Hughes. And if you were really stuck on a certain compression ratio, that could have been fixed by opening up the chambers a bit and selection of head gaskets.

Sheldon
Posted By: DARTH V8Я

Re: 4.15 stroke vs 4.25 stroke what are the pros and cons - 07/12/12 03:45 AM

Well not so fast my good sir. While I do agree with Hughes Engines theory, I do not think it would be the best set up for the street. IMO a dished "D shaped" piston promoted a better flame front, with less chance of detonation and one can get away with a higher CR on 91 octane. Again, just my humble opinion.
Posted By: 451Mopar

Re: 4.15 stroke vs 4.25 stroke what are the pros and cons - 07/12/12 06:53 AM

I guess there was more to this thread than just which crank to use

Really the Stealth heads are pretty small for either stroke length, so as mentioned earlier the small difference in stroke is not a big deal. On my 505" stroker, I only used the Stealth head because I wanted the stock look and the engine will not be turning high RPM levels. I have the earlier stealth castings and they cc at 84cc as advertised. For comparison, my smaller 500" stroker has Max wedge port sized Edelbrock Victor heads, but this engine can see 7,000+ RPM.

The parts Hughes suggested can work, but with 80cc heads and zero deck pistons, the static compression ratio is fairly high (about 11.79:1)
With a cam intake closing point of 70-degrees (a cam that has advertised duration around 290ish), ABDC, cranking cylinder pressure should be about 180 PSI.

The biggest difference I see between using a 4.15" kit and the 4.25" kit is that the stack-up of the stroke, rod length, and piston compression height of the 4.15" kit puts the piston slightly lower below the deck height than the 4.25" kit, so you would have to cut the block a bit more (about 0.010" more than the 4.25" kit) to get the pistons at zero deck?

It is also easier to lower your compression ratio than increase it. Without changing the quench distance, you can work the chambers of the heads to unshroud the valves and polish the combustion chambers. The piston valve notches can be enlarged. As mentioned earlier, "D" cup dish pistons can be used. You could also not zero deck the block. Having the piston 0.006" below deck with a 4.375" bore is 1.478cc added to the chamber volume. Using a 4.50" bore gasket adds 0.413cc compared to a 4.410 " bore head gasket of the same thickness.
Just having 84cc chamber heads vs 80cc will lower the compression ratio to 11.35:1 and with the same 70 ABDC intake closing point, cranking pressure drops to 171 PSI.

I would guess the Hughes HEH5055 cam would have peak power around 5500 RPM? in a 500" stroker?

If you do want to use a milider cam, then you would want to drop the compression.
Posted By: 67coronetman

Re: 4.15 stroke vs 4.25 stroke what are the pros and cons - 07/12/12 11:06 AM

I say use what you have or go with what makes you happy not what everyone else says you should do you will get all kinds of reasons why this or that is better.!
Posted By: DJVCuda

Re: 4.15 stroke vs 4.25 stroke what are the pros and cons - 07/12/12 01:05 PM

Does the OP realize that a higher compression engine, well designed with a proper cam and quench will not detonate as much as a similar one with less Compression and less quench?
Posted By: ZIPPY

Re: 4.15 stroke vs 4.25 stroke what are the pros and cons - 07/12/12 01:40 PM

Further, does the OP realize it takes a considerably bigger camshaft (with quite a bit more duration than Hughes specified) to make a 500ci engine idle "super lopey"?

Posted By: Dean_Kuzluzski

Re: 4.15 stroke vs 4.25 stroke what are the pros and cons - 07/12/12 01:45 PM

Quote:

Further, does the OP realize it takes a considerably bigger camshaft (with quite a bit more duration than Hughes specified) to make a 500ci engine idle "super lopey"?





Maybe he wants it so mild that everyone thinks it still has a slanty 6'er in there!!
Posted By: tboomer

Re: 4.15 stroke vs 4.25 stroke what are the pros and cons - 07/12/12 01:46 PM

I am thinking that the op should just build what he has... I don't think Kevin is steering him in the wrong direction. He treated me well and I only bought some trinkets from them. I am gonna call him later today about some parts. Good luck with what you decide to do!
Posted By: 383man

Re: 4.15 stroke vs 4.25 stroke what are the pros and cons - 07/12/12 07:10 PM

To many peas in the pot. We see it all the time on here. The OP needs to decide who is building the eng that he trust and go with that info. There are many ways to get what he wants and it seems he is getting about 20 different opinions here to confuse it even more. Decide on the one you will trust and go with that. That said I have bought some parts from Hughes for my 493 I built and they treated me great. Good service and fast delivery. Good luck to you. Ron
Posted By: BIGSTROKER

Re: 4.15 stroke vs 4.25 stroke what are the pros and cons - 07/13/12 01:24 PM

go with the 4.15 stroke i have done 3 of them now
and they are very reliable and rev all day long
one with 915 heads 2.14 8.18 valves comp hyd cam rpm 440 850 demon made 450hp @ 5000 and 550 tq @3000 small cam
one with rpm heads 6pk solid roller made 600 hp @6000 600tq @ 4000
one with victor heads solid roller indy dp 1000 cfm hp carb that i have not fired yet
the 4.15 is a true street strip combo that works good
if it aint broke don't fix it
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