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As long as Jmac wipes the squished sealer down haha
Our guys can lay a bead of 3bond like no other
I'm glad you know I'm just bustin Pheakish's chops n not yours.
I wouldn't mind seeing this motor in person Mike when you get it.
If you guys have not already watched some of the videos out there showing a tour of the BluePrint Engines assembly facility I would highly recommend checking them out. Very clean facility. Very organized. Plus, who wouldn’t want to see a bunch of cool machines and awesome engine parts? They have a machine that pops the piston rings into place on the piston in the correct orientation for some applications. First time I seen that on a video.
The combo looks pretty good. Also produces good numbers and is backed up by good reputation based on the comments. If I had to redo my engine stroker I'll seriously consider a crate engine for sure. The price is very reasonable and a proven combination.
Everyone seems to agree that the cast crank in this package is fine. What are the limits of this piece?
It's a good crank. I'd say it's plenty for anything street/strip oriented. If BPE trusts it and will warranty it at their rated power, I wouldn't worry about it.
I appreciate the opinion but I already see that nobody is worried about it. I'll also say that I have no doubts that this engine will perform as advertised and I am not at all considering cancelling my order. Having said this, I'm still perfectly within my rights to be interested in the thinking behind this decision and what it means about longevity and durability of the motor. I can't be the only one who just has a question as to why they used forged pistons, forged rods...and a cast crank? I don't know what brand is being used in this motor but IIRC, the difference in price for an Eagle forged crank over their cast crank is $300ish. Sure, that's a lot of money for a company pumping out hundreds of crate engines but for a person who's already dropping $8k-$9k on an engine, it seems like a worthwhile question Maybe it's because the unspecified cast crank that they chose is just incredibly durable. Maybe it's because there's something unique about the Magnum engine that makes the crank less of a worry (even though Mopar saw fit to used forged cranks in their performance variants of the LA small block through most of 1972 at least). Maybe the limitation on the flow through heads means that the engine is no good past 5xxx RPM and the cast crank is good enough for that speed? I am assuming that one of these things explains it. And yes. I called their tech department with a bunch of questions before putting down my deposit and they were all more or less answered to satisfaction but most of my confidence in the engine came from this thread. The tech didn't know a lot of specifics. Maybe he was more of an expert on the Chevy stuff? In any case, @Johnny Mac seems to have this level of detailed knowledge. I'm hoping he or someone else will know. Basically, I'd just like to know if this is the weakest link in the engine, what it means about max RPM or vulnerability to knock, etc. Does it mean that the bottom end motor is absolutely maxed out? Will it ventilate the block if you go over 5900 RPM? Would the engine even be better with a forged crank? If so, how much better?
It’s an engine designed for street performance, and some strip, not serious racing. Of all the three reciprocating component (pistons, rods, crank) it would be the pistons that were the weakest link, if that’s the term you want to use. They used Hypereutectic originally now they use forged. Everything has its limitations with intended use. But I’m pretty sure they offer a version with a forged crank as well. If there was a concern or doubt about durability I’d think one would just go all forged and focus on something else.
I think my comment came off wrong. My point is that I don't believe you will see any issues with the cast crank. The limits of this crank aren't just related to engine speed though. I'd say several people have pushed them past the rated rpm with no issue. It all comes down to how it's assembled and how accurate the machining is. I've seen in videos how nice BPE's facility is, and I would expect they have very strict tolerances on these engines. I understand having concern spending this amount of money on an engine though, I really do. Contact Johnny Mac, I'm sure he will set your mind at ease.
Being a tier 1 manufacturer, we manufacture, machine, or produce, many of our own parts. Cranks are an example of that. We use the same foundry as the other big name guys that everyone flaunts over, and bring the crank to our facility to balance and machine. In a cast steel crank, vs fully forged, it comes down to the process and material is just worlds beyond what was avail in the 70's. Same goes with pistons. There are alot of wives tails that follow around engines, that are rooted to the quality of parts avail in the 70's. Heck, there are still some people that will tell you strokers in general are problematic because of the rod angle. Our R&D department, and nearly 400000 BluePrint Engines in circulation would say differently So anyways, to the crank specifically. The only thing adding a forged unit to this engine would do is increase the cost. We have cars using this engine running into the 11's out there, and it's one of those things if we didn't think they were adequate, we wouldn't use them. Having never broke one to my knowledge, it's doing its job. These engines make power into the low 6000's as they should for street/strip use. They are built to live, not ring out every last HP. Mopars are hard enough to keep the cost down on, so if I don't have to charge someone another 300 or 400, and the engines make it through all our testing, that's a good day.
doesn't help that mopar magazines were spreading that bullshit well into the 90"s and pounded it into peoples heads as they were coming up learning..
the important thing with the crank is it's cast 'steel' not cast 'iron' so much stronger.
The biggest drawback to a cast crank is its lack of mass. Any time you have to externally balance a crank you compromise the crank.
This background is very much appreciated. Can you share which OEM your company supports? In any case, hearing that you machine the cranks to your own specs goes a long way. Clearly BPE is taking ownership over the performance and functionality of this part of the engine. That says a lot. No doubt, cast cranks are vastly better than they were in the 1970s...but this makes me curious. I have a modern Ford in my garage with a V8 engine (that makes less power than a 408 stroker) and Ford, not known for being particularly "generous" saw fit to include a forged crank shaft in the Coyote. This particular engine has a higher rev limit than the 408 but also a shorter stroke length (presumably similar piston speeds...too lazy to do the math ). It also has sophisticated fuel management which undoubtedly reduces the punishment taken by the rotating assembly. So if it's just old wives tales that say modern cast cranks aren't up to the task for a street performance engine, why did Ford go this route? And yes, Chevrolet uses a forged crank in the current gen LT1, Dodge uses a forged crank in the 6.4L/392 motor as well. The question isn't specifically directed at Johnny Mac...
As an aftermarket performance engine manufacturer we are an OEM. Our industrial division is a tier one to various private label contracts. The material comparisons fall apart for me a bit since the 5.0 coyote, most LS, most LT, and 5.7/6.4 hemi all use hyper pistons. It's my opinion you can't compare apples to oranges on one level (cranks), then turn around and ignore apples to apples (pistons) on another. Just my high level opinion for what it's worth. More than one way to skin a cat. More than one way to assemble a reliable rotating assembly.
Honestly, this engine could make 800hp and get 40 mpg and you would still have something irrelivent to ask of it. Seems to be a classic no win situation. There is a difference in being an informed consumer, and just being impossible to please.
When reading up on these crate engines, I have seen your other posts from you where you’ve galloped in on your white horse to save BPE from criticism. It’s a nice gesture. I hope they gave you a discount on your engine or something. By the way, which motor did you buy from them? How did your make your purchase without asking questions?
Again, I do appreciate these responses even if the questions seem critical. Just for the record, rescinding my down payment is not on the table just because I’m asking these questions. Despite my confidence that there were good reasons for the choices made on how/why these engines are built the way they are, I wouldn’t sleep well at night not knowing what these reasons were. I am also anticipating a risk to my pride when my friends start asking questions about my new engine and I have to shrug my shoulders. I just like to know these things and I know I’m not alone in that. As for the answer, it doesn’t completely help me understand but it’s also not fair to expect that you would have any insight in engineering decisions made by auto manufacturers. I got ahead of myself with the “Tier 1” thing which doesn’t mean exactly what I thought it did in this context. Anyway, I guess I was hoping for some explanation about the forces applied to crank shafts and why one application would require x and another gets by just fine with y. In any case, I believe your conclusion and you obviously don’t owe me any answer at all…so thanks.
No worries here. You are correct I'm not an engineer, but I am an engine builder, and I do trust my teams decisions. Some more insight, we have a machine in the back called a crank breaker. I'm going to over simplify this, but it's basically a sound resonance machine that shoots sound waves at a crank, and you can physically see the crank vibrate. They have calculation relative to piston speed, stress on a journal, etc. You can physically see it vibrate. We over stress the cranks, see where they fail, and make decisions from there. It's quite a process.
The title of this thread should be corrected to read: Only interested in validation of my own Thoughts/opinions on Blueprint Engines 408 stroker crate engine.
One question Are these cast cranks internally balanced or externally? I would think if you are balancing the crank in house they would be internally balanced. Everyone seems to be very happy with this motors.
Well said Johnny Mac, I would not want your job for love nor money.
I’m sure that some here are going to think I’m committing libel against BPE for asking another question. What oil pan is included with this engine? Is it the LA style/car specific shape? Does it have a windage tray? IIRC, the Ram/Dakota pans won’t fit in car applications and the LA pans don’t fit perfectly on the Magnum engine but folks make them work.