My lightweight one-piece rear seal crank is from Eagle. It's several pounds lighter than the stock crank...48 vs 52 as I recall. It's forged and was ~$700.

The issue with Eagle is machining consistency. All the journals on my crank needed to be turned. Really ticked me off but it all worked out in the end.

I used SCAT lightweight H-beam rods. In my 383 thread there are some side-by-side pics of my old SCAT H-beam rods and the new ones. The difference in weight is significant and it's obvious in the pictures.

Pistons were the challenge for me. I used SRP which were fairly light. The battle was finding an inverted dome that would give me the CR I wanted. As a result I ended up having to compromise a little since custom pistons weren't in my budget.

 

I've got Forged pistons and a cast Scat crank...I wanted to run a healthy dose of gas but never got around to it. It's been pretty dependable, if a little thirsty on the oil. Had I known then what I know now, I'da stuck with Hyper pistons and saved a little money on oil.

 

I watched your thread and I remember seeing issues with the Eagle crank which is why I wanted to stay away. How much did it cost to have the cranks machined properly? The rotating assembly is going to be the biggest expense of my build, and I am trying to do it on a budget, although it might be worth it in the end.

 

My machinist really wants me to use forged pistons he recommended a Keith Black set.

I have a new hot cam and ported 113 heads, they only flow 235 at .500 though.

Going to the 383 would cost me losing a track event, since they cost about the same. I think I'd rather attend the event but I want to be happy with the engine for a long time.

Interesting about the dyno gain with the pistons. I had heard that before but not see a HP number.

Power band, I'd like the engine to live a good long life plus I have a SR and wasn't planning different rear gears.

 

We had to stop using Eagle stuff years ago and maybe to the average guy that don't have anything to measure with it would be fine just looking at a shiny crankshaft it looks good.

It would hard to find bearings to fit a tapered journal seeing bearings are not taper

We tent to stay with the Callies Compstar line and there pricing seems to be really good. and Scat would be my second choice.

And over the years building engines I have had to many calls about broken or worn cast cranks.

If you ever had to the chance to drill a cast crank or 4340 carnk when balancing, The cast crank is like drilling butter compared to a good forged crank.

We stay away from cast cranks and Hyper pistons and so far I don't see the problems my competition is having and we do a lot of balancing for other shops and local guys building engines os we see whats going on out there.

Don't get me wrong not every Eagle crank is junk but I don't have time to keep sending them back when they don't pass my inspection.

Here is a link to look over.

http://www.yellowbullet.com/forum/sh...d.php?t=114102

 

Does Callies make one piece rear seal lightweight cranks? How is their pricing compared to Scat and Eagle?

 

I think their pricing is pretty good and the Callies rods when you break them down and retorque them they don't change demension and they come with ARP 2000 series bolts.

One peice seal cranks are available. The light weight cranks are cheaper then some of the Scat light weight cranks.

Hell I can buy 4340 cranks for 325.00 but there not very good quality and H-beams for 175.00 by I will pass on the stuff.

 

I don't recall. The shop turned the journals 10 thou. I looked at Callies CompStar line and it was about the same cost as the Eagle lightweight crank but several pounds heavier.

That's the hardest part about building an engine...When are the parts that are selected "good enough" for what the user intends? You see some guys with tens of thousands in engines that do nothing but putter around the street and then you get some of the Mustang guys that go thru the proverbial $200 engines like candy.

 

I saw they have lightweight in 3.75" stroke if Andrew goes that route, but only standard weight in 3.48" stroke.

Ill see how your engine holds out this year before I build mine!

 

Well my stock crank just needs a little polishing to be ready. Rods are okay too. I just don't want to race it, have it fail, and be pulling it again.

 

Practice makes perfect! (In my case, it was the slushbox, not the motor, but the result is the same.)

 

For what the 383 costs I could also pick up a spare short block to have ready.

What I'd like to do is go down to the store, get some beer, drink that all up, then decide what CID I'd really like.

Anyone have a decent 383 cam they would trade for a hot cam?

 

Actually....I was about $200 for a seasoned block...it let me keep the numbers matchine block, and then just transfer stuff to the new motor as necessary when I did the install...it meant the car was down for a much shorter period of time. It ALSO meant I got a seasoned 4 bolt block instead of the two-bolt stocker.

 

Engine simulations might give you more insight on your choices. Obviously, your desire to race in a certain class and it's rules play a big factor too.

I spent the last 6 months talking to lots of people looking for the "right" answer so some of the questions you posed here, like: hypers vs forged, 5.7" v 6" rods, longevity, Scat vs Eagle, forged cranks vs cast, engine life at higher rpms, etc.... I talked to multiple forum members and multiple (local) builders. The conclusions I found are these....

Inverted dome pistons are better for various reasons. Flame travel/consolidation create the best burn and efficiency. You can get the highest compression and/or best efficiency (esp w 58cc heads) using that design. More info on that here: http://www.kb-silvolite.com/article....n=read&A_id=36

Everyone (except the builder I chose) agreed that forged pistons are a better choice than hypers. Kinda ironic LOL! Had I not found a great deal on eBay, I probably would have used the KB9926 inverted dome pistons for 5.7" rods @ $275. Because I noted inverted domes can increase heat (mentioned in link above) while 5.7" rods help to reverse that (because they're slightly faster pulling away from TDC), this sounded like a good combo IMO. Also, these have the higher Silicon 4032 Alloy and run at slightly tighter tolerance than standard 2618 forged. SRPs Pro series were may favorite choice but higher priced. Lighter than heck though.

Scat cranks are harder than Eagle as testified by builders who'd drilled into both. Also, no builder was skeptical that a cast crank wasn't strong enough for the level of build you (we) are building. And, they are 1lb lighter in the 9000 Series at 51lbs.

A 383 will run as long/well as a 350 if built/balanced right. No need to worry about going to a 383.

Without looking at your gears (ratio), converting to a 383 will add torque EVERYWHERE. Off-idle all the way to redline. It will go alone way to satisfying your need for higher torque. (Obviously, a 383 and higher gears would be fun too!)

The hotcam could be improved upon -- going to a 383,,,but you also have the issue of 235cfm stock heads to consider. More headflow or more duration could feed it more air. Depending on your desire and/or long-term plans (if any) to upgrade your cam and/or heads could play a part in deciding the best CID for you.

 

Thanks for the thoughts. I was reading a post on TGO with a hot cam 383 that made just over 400 crank HP. I suppose I would upgrade in the future, it's fun to work on.

 

What intake was on there? I no expert but I dont think the hotcam and the SR work in the same RPM band.

 

I quick note that must be kept in mind when you build the engine. An inverted dome piston only works better then a flat top piston when it is designed to match the combustion chamber in the head. A flat top piston is the safe route to go when you decide to build an engine because it promotes high turblance in the combustion chamber and will work well as long as the squish is kept around .040. A inverted dome piston can perform better then a flat top piston if the inverted part of the piston matches the combustion chamber. If you have an inverted dome piston that does not match well with the combustion chamber it will have a tendancy to detonate, create heat, and not perform well. Most off the shelf inverted dome pistons will not match the combustion chamber since neither the piston or the head was designed to work with all possible combinations. To make an inverted dome work properly you must research the piston design to get one that was designed for the combustion chamber you are running. That is why in my opinion most people should run flat top pistons, it is easy to make them work properly. Inverted domes have their advantages but they are easy to make mistakes with and can easly result in an engine that will perform poorly.

 

Do any match up well with the 113 head?

 

Flat tops are hard to get within a reasonable CR and have a .040 quench. I have been looking at parts and a flat top piston generally has -5cc in the valve reliefs. To get a reasonable compression ratio (for instance I cannot be higher than 10.75:1 for my race class) is to have the block decked to 9.015 and use a .042 gasket. This makes around 10.7:1 but the quench is .057. Granted its better than the factory setup but in order to have a .040 quench I would end up with over 11:1 CR which myself (and Andrew) cannot do without taking extra points for our race class.

 

To lower compression, a machinist can remove material from a head. Since Brian is emphasizing matching shapes, I wonder/suggest if removing material from heads and/or pistons to get an inverted dome more closely matched in shape meets that criteria. The bonus would be if compression can be lowered to get under the limits imposed by their class.

That's using a flat-top. Otherwise, if Kubs calculations are correct, then an dish is going to lower compression enough anyway.

BTW: I'm going to double-check the calculations later today. It's kinda hard for me to believe a flat-top can get 10.7:1 with a 58cc head. Figuring out the approx dish size will help to figure out what inverted dome pistons are even in the running. With a 383 and 56cc head, I was looking at 10.7:1 with a 16cc dish. (.040 quench).

Knowing the desired CID would help too!