few more 416 questions

[djwhog]

OK I have a set of eagle small block mopar H beam rods and the 4" forged eagle crank. . ross forged 9.6 dished pistons. Just to double chk, the rods go on the crank with the oil hole facing to the inside of the piston walls, and the bearing tangs out correct? I see that on the rods that the big end of these rods has one side with more offset. And it appears to me the large offset rides to the outside of the crank journal flangs thus centering the piston pin in the piston.

Also on the speed pro single moly 1/16 rings for a street / strip no nitrous I see that the new specs are about .018- .020 for a 4" bore on the top ring and about .020-.022 for the 2nd. In the old days we used to go a lot tighter on the 2nd but from what I have read and what was supplied with the rings the new specas are about .005 per inch on the 2nd ring.

Is that pretty much what most off you guys are running with?

I know if it was race only on the loose side is better when more heat is created as a rule of thumd. Just want to double check here.

thanks! :salute:

 

[moper]

The tapered side of the rod's big end journal faces the radius of the crank. I like to assemble fron to rear, so I mark each rod beam with the cylinder number on the surface that faces the front of the block. I do the same with pistons. Most times I dont have to dismnout and turn the rods around after when I do it that way...lol. Most times...

As far as ring gaps. You have good pistons, and good rods. If it were me, (because I am pro-NOS use)I would gap the rings on the NOS spec. It sure beats sweating bullets alter should you decide to pick some up. If you think you wont ever want it, I would go .019 on the top, .022 on the 2nd. What better builders found is, the top ring is sealed by pressure from the top and rear of the ring forcing it against the wall. If any pressure builds between the 1st and 2nd ring, that force is lessoned, and it causes a domino effect where the top ring doesnt seal well, then the pressure builds between the rings, then the top ring seals less...etc etc etc. That's what can cause ring flutter at high rpms. In tight ring grooves and good rings, this is minimized. But as the engine wears, the problem will get worse. So they increased the gap in the 2nd ring, because it's job is not compression retention. It's job is oil control so the top ring can seal better.

 

[djwhog]

Thanks moper! Yep that is the way I have it. Just wanted to make sure. So when the bearing tangs are pointed out on these rods the large end has the one side that has a chamfer and the other side is more flat and wider. The 2 wider sides go togther and the tapered side as you said rides on the outside crank.

I had no ring fit them back when I cut the block for bolt clearnace and I noticed that they are more centered in the wrist pint - piston when they are this way. But I have seem some weird stuff and needed your exprt help thanks!

I agree on the ring gap too. I seriously doubt I will go NOS, but I did go on the loose side of the spec for the 1st and 2nd rings. This is more of the race spec than the street spec, and one would need another .004 to each top and bottom for NOS according to the docs.

I just needed to be sure, I was 2nd guessing myself and have done so many 100s of engines ( mostly years ago) back in the day used to be like .003 for each inch of bore for the 2nd rings, today it is .005+ per each inch.

times are a changing! thanks again Moper.
:headbang: :headbang: :headbang:

 

[moper]

I was taught .004 per inch of bore as a baseline. But really, every build could be different, depending on parts and usage. Now add in the other post about Total Seals ideas...I'm starting to doubt myself too...lol.

 

[djwhog]

I was taught .004 per inch of bore as a baseline. But really, every build could be different, depending on parts and usage. Now add in the other post about Total Seals ideas...I'm starting to doubt myself too...lol.

Yep I am not claiming to more than total seal ( I read their stuff ), but I have seen in 100s of engines the results of to tight or to loose. I kinda view some of that stuff as marketing like the days of GM saying you only needed to change oil every 1k miles.


I think we are good to go and loose is better than tight... well when talking about arings.. :icescrea: