OK, I think I've gotten past the hoopla concerning what quality of parts to use....I don't think the shortblock is an area to cut corners if you want to do it right. I've narrowed it down to Eagle 4340 rotating assembly or the same with a Callies crank. Now it is time to decide on 383 vs 355. I thinkI have decided on a 383. I know many of you will scoff at the idea of using a Powerdyne with a 383, but I plan to do it right and build for growth. I will use the new larger TFS heads since they are a pretty good deal complete at $1,200 and sell my old heads for some cost recovery....I'm hoping they will flow what I need right out of the box. The cam will be a custom grind based on the bore/stroke/boost/CR/and approx flow numbers of the heads, it will likely be somewhat similar to the 224/236/114 cam. The overall extra cost of a 383 will be what, $300 ? Combined with bigger heads and cam in comparison to a 355 it should make significantly more power, even at the top end probably another 10 HP or more. I would think the mid range torque will be quite a bit better with the 383+bigger heads/bigger cam and allow me to use a lopier cam without sacrificing a lot of bottom end (maybe 40+TQ at the midrange).

As for the Powerdyne, yes ...it is a limitation. However, as long is it makes 0 or more boost ....it should be providing enough extra airflow for an additional 100 hp. This means it's still doing it's job which is fine with me. At least I have the BD-11 model with some mods (you'll see). If I build the engine right it will tolerate an S-Trim with intercooler or a 50-75 shot easily later on....and that's all I'd ever want. The downside is the cam and CR are at first going to be optimized for the Powerdyne.....limiting a perfect matchup later on with more boost or a tiny squeeze of gas. To compensate for that I'm thinking I should go 9.7 or so on the static CR to allow for a little more boost or a tiny shot of spray later on....and maybe taylor the cam to make an effective CR of 7.9 or so. This should allow for growth if necessary and still provide decent throttle response should I never switch from the PD.

My machine shop says the crank and rods, and even the mains look just a little more worn than they'd like to see to be used again. I've decided to go all forged anyway......so especially if I need to replace or recondition the mains I may as well go with the 4-bolt configuration, as staying with the 2-bolt setup would then be a weak link.

I also think it would be smart to use a crank that is already keyed in case I'd want to use a keyed hub later ......or should I do that now? My 42# injectors may be at 100% duty cycle without an FMU though, I will bring my old PD FMU to the dyno for backup.

I think if this is tuned right the 355 or especially the 383 will make ~500 RWHP even with the Powerdyne (6 PSI kit w/solid intake conversion, large K&N, overpullied by 7.5%, Paxton bypass valve, ....makes about 8 PSI on stock motor).

470 - 500 RWHP is all I'm looking for now. In the unlikely event that it's not enough I'm thinking a small dose of gas or extra boost to put it closer to 600 is all I'd ever want. I want to build it strong enough to handle that to err on the safe side in case I never do it anyway.....make sense? That also helps protect me from bad tuning, fuel system failures, etc, as well.

Sorry this is so long. Does anyone have any advice to the contrary or otherwise?

 

I would suggest that no more power than you are wanting to make go with the eagle crank over the callies and put that money toward an S-trim.

Maybe look into getting a set of stock heads ported rather than out of the box Trick Flows, or look around on here for a set of ported heads. A friend of mine has a set forsale thats being freshened up at Total Engine Airflow.

Something else to think about is the limit of the powerdyne. What is the max cfm of the powerdyne? It doesn't really matter what cubic inch, heads, cam, intake, etc... you have if the blower won't flow enough to take advantage it. If you are already maxing the blower out with a stock motor you won't gain much HP by building a better breathing engine. All it will do is lower the boost and drop the air temp a little which is worth a little but not near enough to justify the cost.

My 2 cents.

 

Thanks for your input. The main reason I'm thinking Trick Flow is the size of the heads and valves would be better for a 383, mainly the 195cc intakes and 2.02/1.60 setup. This is what you really need with a bigger CID motor from what I have learned. I lack the sheer technical ability, but some guru's who have experience tell me the overdriven Powerdyne will still make 100 HP .....whether the boost gauge shows 0 or 8, it is really the extra airflow that makes the power....as long as it's not below 0, thus creating vacuum and restriction. Boost is nothing more than a measure of intake restriction .....the lower you can make it the better really. I would only use the PD until it breaks, then I would step up to an S-Trim with an ATI air to air unit. The faster the air can move (less restriction and cooler temps .....also less load/parasitic drag on the crank) the more power the motor can make efficiently.

 

I'd budget a better supercharger into the buildup. If that powerdyne is allready maxed out, you won't see that much of a gain over what you had before.... it won't be flowing any more air than it did before, so most of your gains will come from being more efficient. It'd suck to drop $4-$5k and only come up with an extra 30-40hp.

I'd sell the powerdyne before it breaks, might get a little more for it that way.

All aftermarket cranks that I know of come keyed. $70 for a keyed hub is cheap insurance from destroying your crank from a spinning hub.

 

Depending on what you mean by "maxed out" ....from what I know the PD is nowhere near it as far as becoming a restriction.....if impellor rpm is what you're speaking of then you are correct. If it's making 8 PSI on a stock motor with long tubes, 1.6RR's ....I'd say there's some room to grow powerwise with heads and cam, and even displacement. I know of others who have made 450 RWHP with carelessly matched cam/heads with the Powerdyne and 355, that is 66 more RWHP than I have now. I'd say I can easily pick up 100 RWHP from the following even while keeping the PD: 383 + TFS heads, matched cam, 52MM TB, Meziere waterpump, good tune. Do you not agree? Thanks for the advice on the keyed hub. Honestly 100 RWHP is all I'm looking to pick up, even with the Powerdyne I think that is very doable via heads/cam/stroke/52MM/Meziere/tuned ......vs stock ......no?

 

Sounds like a good plan. I like the Callies "Dragonslayer" crank better than the Eagle, it's not much more expensvie, and it's made in the USA to boot. Clearly, since you buying a new rotating assy anyway it makes sense to go for a stroker. No extra cost to speak of and more hp potential. I don't know of anyone using the heads you are considering, so I can't comment one way or another. You sometimes see used AFR's F/S, so you might consider that route.

Good luck.

Rich Krause

 

Thanks for your input Rich, it always helps when someone as knowledgeable as you chimes in and agrees. I am beginning to scoff at the total cost of a well built motor though To go with fully forged shortblock w/4-bolt mains, a good timing set, heads/cam/dynotune, bigger throttle body (should probably do the 58MM really) .....it looks like I will be out of roughly 6K ! Then add the cost of an LT4/SLP lightweight combo or Mcleod, a Meziere waterpump, new opti, my mechanic's labor .....damn, we're at about 8 - 8.5K ....and I haven't even bought a 12 bolt or driveshaft loop yet

I am rethinking the idea of just doing the shortblock since it's the only thing that has failed and putting it back together since the stock heads/cam are good @ 44K miles and I have new 1.6 RR's and 103-08 springs along w/new lifters. It just sucks to not go ahead and do new heads/cam/other upgrades while at it because the labor won't be any extra at this time. If money wasn't so tight right now I'd go all the way without thinking about it too much .....but this is going to be a sacrifice for me and I've already sacrificed so much for this car

This is why one must think carefully about doing anything beyond bolt ons .....spinning bearings and/or cracking pistons is something so many of us can't avoid. Whether we do cam/heads, FI, or N2O ....there is always a good % of us who rebuild as a result. Us FI guys seem to have it the worst, even us measly Powerdyne guys usually rebuild (I took every precaution I know of to prevent this exc running the 4.5 or stock 6.0 kit ....which wouldn't be worth it anyway) My bearings were the failure ....so having an intercooler probably wouldn't have saved me.

Rich, just to be realistic .....what will a fully forged assembled 4-bolt shortblock cost .....about $3,500 to $4,500 depending on parts? I'm thinking the Eagle assembly with SRP pistons is the way I should go since money does matter to me some.....sound like a good choice? Will this handle the 75 shot or S-Trim later on?

 

I think the Eagle rotating assy is good. If you really are planning on N2O plus boost though I think you should strongly consider a JE, Ross, or BME piston. The pistons are the potential weak link. If you have a $1,500-2,000 rotating assy. the whole thing should be in the lower end of your price range.

Rich Krause

 

Rich, not sure what your last sentence really means. However, I guess you are saying the SRP pistons aren't so great hugh? I've heard of people running a lot of boost or N2O on them with no problems. All I would ever use beyond the PD and heads/cam is either a small shot with my small boost ....or ......a little more boost (S-Trim), that's it.....and it's really unlikely I will do it. So you're saying the Eagle assembly is good for it but the SRP's may not be .....am I understanding correctly? Someone told me they ran SRP pistons with a D1-SC at 15 PSI with no issues .....were they just lucky or something?

 

I am not saying the SRP pistons are no good. They are excellent. It's just that the pistons are exactly where most blower cars run into problems. So, if there's one place to splurge it's the pistons. The SRP's are good though, no doubt about it. We are not talking absolutes here, just incremental improvements.

I just meant (in the last part of my post) that your $3,500-4,500 price range was very reasonable.

Rich Krause

 

Well, after doing a search I've gotten some shady reviews on TFS heads and they are too new to be a guinnee pig for. My budget for heads is 1K .....that is it. So here's the new question: It seems that Lloyd Elliot heads are the number one bang for the buck head and work very well on a 355. Will they work well on a 383 too or are the stock 170cc intake ports just not enough regardless of valve size and quality of port/polish? SC + 383 = lots of air ....maybe the LE heads just wouldn't cut it?

I'm starting to realize going 383 could cost me quite a bit more if the heads are a big issue. Machining $200, 58mm TB $300 (can get a 52MM from ASP for $150....they bore your stock 48, I would guess 52mm is plenty for a 355 but maybe you'd be better with a 58mm with a 383), big heads that flow well enough to support a 383 may be quite a bit more.....from the search I did it sounds like you really need to spend about 2K for heads sufficient for a 383. I can get the Lloyd Elliot heads for about 1K for my needs and know they will work great on a 355 ......it also seems there are more budget forged 355 cranks .......oh boy, here I go again.....

decisions, decisions ......I need any input/advice you guys can offer as always

 

on a FI motor, the intake runner volume isn't near as important as it is for an NA motor. The flow numbers are going to be important though. I would go with a well-done stock casting.

 

Agree.

Rich Krause

 

So you all are saying the Lloyd Elliot heads would probably work better on a 383 than out of the box Edelbrocks or even the larger TFS heads (also out of the box)? If so that is really good news. The truth is I want to do the 383. I can use a nastier cam, and have more midrange torque ...along with a tiny dose of top end compared to a 355 (I probably already said that).

 

a lot of what you're paying for in aftermarket heads is a different casting with more runner volume (which is really important in NA cars).

On a NA car, if you get 2 sets of heads, both flowing the same, one with 210cc runners and one with 190cc runners, the 210cc is gonna put down more power because there is more air available for the vacuum of the cylinder to pull in (there's a lot more to it than that... but generally speaking, this will give you an idea).

In the case of FI, the runners (and everything else in the intake for that matter) is pressurized. There's not a lack of air, so the runner volume isn't as important. Flow is still important because you have to get the air into the cylinders, pressurized or not.

A good set of ported stock castings will generally flow as good as or better than unported aftermarket castings (just that they have less runner volume). So, the answer to your question in regard to forced induction is probably yes. You'll probably see a little more power out of the ported stock castings.