I was told to post this here as this is where alot of the guys hang out that know there motor stuff!

I am building a 383 for my 88 C4. Here is the link I just posted in the C4 Tech.http://forums.corvetteforum.com/show....php?t=1618979


Hope you guys can help out. Some ppl say Eagle sucks. Some people say it's great. All I know is that it's priced somewhat affordable.

Hope you guys can take a look!

I would like to find an assembly that with my 65CC AFR that are on order I can reach a CR of around 10.3/1. However I do want a forged assembly. I am kinda confused on what kit to buy. My budget for the kit is around $1300-$1500.

 

I have personally never had a problem with an Eagle crank or Rods. We have abused them pretty hard and have not had a failure. With that said one crank that I was really impressed with the finish was the Callies crank that we used a while back. It was priced down around the Eagle stuff so we thought we would give it a try and had a really positive experience. The finish was very good (better than eagle) and everything was on the up and up. What I would do if I were you is this; being your first engine you want to learn as much as you can so why buy a kit? If you know the deck height of the block you can calculate all the dimensions you need. So say you have a 9' deck height and want to run a 3.48' stroke. What length of rod would you like to use? Lets say 6' H Beams for this engine. so take half the stroke and add the rod length, your desired clearance, and then subtract all of that from the deck height and you will find your needed pin height. Once that is done you pick your piston out, compare what cr you can get with your current head combustion chamber and increase that as desired. This is the best way of going about putting together an engine as it gives you the freedom to choose what parts you need in what places. Can I ask what type of power and environment this engine will see? It may be totally possible to run some "weaker" parts depending upon what the plan and purpose is. Sorry for the long post, if you have any questions you can post them here or pm me. Hope this helps.

 

Don't worry about the long post. Longer the better. I am just starting to learn about this stuff from Pete K and Mos90, and others. The engine will mostly see street application, and I will visit the track maybe twice a year. If you could suggest some options to me that would be excellent. I am going to be building a 383. It is a 2 bolt 87-99 1 piece rear main seal block that the mains will prob be splayed. The combo I am aiming for "should" rev up into the 6100-6300 rpm range. What else do you want to know? I want the CR to be around 10.3-10.5.

The heads I have on order are the 195 CC AFR's. They have the 65 Combustion chambers, and they flow like the mississippi. You mentioned the callies cranks! Are they the top of the line?

Justin in saying that. Is there anyting wrong with that Eagle Forged kit in the above link?

 

Well no, generally Callies crankshafts are considered good to very good and hold up well in race applications for the $1500-$1900 you spend on them. A top of the line crank will be a Briant, but in the area of $4000 they are a stretch for most of us and the wait is terrible sometimes. With that said, for your application, the Eagle components in that kit will be just fine. I have personally run their forged cranks and H beams with standard bolts out to well over 600 hp and 7500RPM. Some 360 sprint guys that I know use their rods, but they tend to weaken up and need cycled quickly. If this engine will not see any nitrous I would recommend upgrading to the total seal max seal ring set. This will help with longevity and has given us some "free" horse power in the past. I am not really a big rod bolt guy; from the guy with the $500 bolt upgrade in his Carrillo's lol, but you could upgrade those as well. Is this engine going to be EFI? If it is, with the aluminum heads I would simply massage the pistons a bit, do the same with the heads and unshroud the valves a bit and run it. One thing to consider to is the camshaft profile that will be used. To pull very hard to 6300 in a 383 you will need more than a little duration @50 (and you will run out of cylinder head) and that tends to pull the dynamic compression ratio down, allowing what looks to be too high to be optimal. What cam are you planning on running, is this an auto or manual tans car, are you talking road race or drag? Also, what type of fuel do you want to run through this engine? For what you want to spend, the kit in the link is about as good as you are going to get and for what you will be doing it will be entirely adequate. Just asking, what is the hp/rpm goal for this engine?

 

We have been using the rotators from Scat and so they have been very good in quality as we do a lot of balancing and machining for other engine builder and smaller shops and so far EVERY SET OF EAGLE SIR RODS that we have seen that when taken apart and retorqued they seem to go out of round up to .003 and this seems to cause a lot of problems with the people who own them.

Remembe when buying one of these kits that are not ready to assemble as advertised as the rods have to be correctly sized both ends and pin bores pitons have to opened up and the rings have to be fit.

We have also checked a few balanced rotators for balance and have not found them to be very close as when the customers bring in there parts to be checed out nothing has been taken out of the packages and the piston box is sealed so how did they weigh everything.

And going to 3 center splayed caps is a good idea as we see a few 2 bolt blocks that have been used in 383 that seem to push the caps around.

To bad you didn't live so far a way.

 

The issue of these cheap rods being out of round has been discussed before and not just the SIR rods either. I'm not familiar with the Scat rods, but for me it's always worth the extra dollars to buy Crower rods. After the time and money you spend to rework a new set of cheap rods you might as well start off with some quality pieces. For a mild street 383, a well prepped set of GM rods are adequate too.

 

I believe the kit contained the ESP rods; which we have never had any issues with either on the big or little ends. I am not a fan of the SIR rods since they really are cheap but the ESP's are fine, and their finish is nearly as good as rods like the Carrillo Pro H; and for the money I would hope that there was some difference at least. For a street engine or a race engine where RPM are kept below 7800RPM the Eagle ESP's seem to work well. The rings will need to be fitted up for the cylinder that they are going to run in, the assembly will need balanced (have a shop that builds serious competition engines do this!), and the connecting rod side clearance will also need to be set. Just start off by mocking it up and taking measurements to see where everything is at and go from there.

 

Is this engine going to be EFI? Yes. I will be using the TPIS Miniram intake with probably 30's or 32 pound injectors.

What cam are you planning on running, is this an auto or manual tans car, are you talking road race or drag? I am planning a cam with the following specs. 226/226 .565/.565(these are the 1.6 roller rocker specs). This cam is not set in stone. It is a 88 4+3 car. I will be doing a little of everything, but mainly street use.


Also, what type of fuel do you want to run through this engine? Well we have all the way to to 94 octane. If I could get away with 91-92 even better.

Just asking, what is the hp/rpm goal for this engine? With the heads that I bought. The new AFR 195cc that flow unreal for a 195cc head. I would like to see somewhere in the 380rwhp-400rwhp, and 380 rwtq-400rwtq.

 

Everyone will have their preferences and eventually youll hear of breakage on jut about any brand. Rick, the Eagle assy will probably be fine but avoid the SIR rods, the above info on them is all too common .

 

Ok, with 226@50 for duration the engine will not be able to produce really good power up top. That is something that will have to be sacrificed to pass emissions. Myself, I would try to get a cam that is into the low to mid 230's@50 in the 383. The longer stoke will tame down the cam and should still allow you to pass emissions (I do not know for sure since race cars don't have to pass smog!) and give you a little more up top but if you want to be safe the cam you listed will work ok. Now with the goal being in the 400 range on both hp and tq I would look away from the forged eagle kit. At those levels I would look for lightweight components for all the parts, crank, rods, pistons. The bottom end you are looking at would work in a low end spec'd 360 sprint car bottom end. The components are heavy and really do not need that amount of strength in your application. It will cost you some more money (a scat forged 4340 pro comp supper lightweight crank will cost $1100+) but in the end you will have a much better combination since you are limited by the emissions testing. If you were not we would put a much larger cam in it, a little more cylinder head on it and call it a day with the eagle stuff and let it spin to 7300RPM to make all kinds of hp. But since you don't have that option you can do one of two things, 1 run the eagle stuff and NEVER break anything while giving up some power; or 2 you can invest more money in lightweight components and gain a little. For a hot rod we would go with the eagle kit and know that we had nothing to worry about.
Also, since the engine will be EFI I would massage the pistons and chambers (unshroud the valves a little while you are in there) and run the 92 octane fuel in it. The cam is tight on duration so it will not bleed off enough to make a difference (well, one that we are worried about anyway), so with the massaging and unshrouding you will be down to about 10.75:1 and should not have any problems with it as long as the computer is set up handle it. I love the Fast XFI stuff but it is pricey, but I would recommend getting something aftermarket that you can work on and learn to set up with a nice user interface. That way you can always monitor what is going on if you think that something is off, and if there is a problem you can deal with it right away before things get out of hand. With this combo you should be able to easily make your goals and have an engine that can take whatever you throw at it no matter what road you choose! If you have any other questions let me know. Good luck, hope this helped out!

 

Thanks for all the answers guys. Much appreciated!

 

My first 383 had the Crane SBCircle roller with 232/240 112. Wonderful cam if you keep the compression below 10.7 or so with al. heads.

It only gives a hint of its true power with a mild lope