Manley Rods with 8740 bolts

[Sleepinbeauty]

I recently purchased some discounted Manley H-beam rods. The advertisement was claiming up to a 1000 hp with these rods. I knew there were people who had produced that kind of power with these rods. I naturally assummed that these rods came with ARP 2000 bolts; however, when I recieved them they had 8740 bolts. Is it possible for these rods to handle 800 plus horsepower with this material rod bolt. My plan is to make from 650 to about 750 at the crank, but I like to have the inurance of knowing that the bottom end will handle more.

 

[Blkkbgt]

From my own research I have found that some believe the limit for an 8740 rod bolt is 700hp. Did I ever find any concrete proof such as a failure of those bolts above that power level? No not a single one. From what I understand the bolt wont fail but it will stretch and the bearings will spin. One of the places I found this info was on modularfords I believe so you can search over there or just use google.

If it were me at that power level I would upgrade. ARP 2000's would be cheap insurance at that point IMOP.

 

[01yellercobra]

I was somewhere between 600 and 650 at the tire on my last set up. I had the ARP 8750 bolts and didn't have any issues. If I was looking for more I would have upgraded the entire rod from what I was running anyway.

 

[Sleepinbeauty]

I checked out the Manley website and they have a rating at 700 hp. I going to switch over to ARP 2000 bolts simply because I don't know whether that rating is for the 3/8" or the 7/16" and unfortunately, I have the smaller 3/8" 8740s. My machinist said there was no need to recondition the new rod. Just swap the bolts. I had no idea that there are literally 11 different bolt availabilities for the 14042-8 Manley rods. Thanks guys!

 

[01yellercobra]

The rods need to be checked after installing the new bolts. The different bolts have different clamping forces. You need to make sure the opening is still round. That's why machine shops redo the rods when changing bolts.

I'd be a little leary of a shop that wouldn't even check measurements and would assume it's fine.

 

[ashleyroachclip]

I am with slow98fornow ,
Because my machinist checks every step, my 16 year old 347 on a 200 shot , has not had a single failure of any kind .
I drive it like I stole it at the track , after I drive 90 minutes to the track , then drive it home .
To make matters even sweeter , 27 mpg to and from .

 

[Sleepinbeauty]

The rods need to be checked after installing the new bolts. The different bolts have different clamping forces. You need to make sure the opening is still round. That's why machine shops redo the rods when changing bolts.

I'd be a little leary of a shop that wouldn't even check measurements and would assume it's fine.

Definitely, I will investigate more when I speak with him. I prompted the question to him about the reconditioning. Now, from past threads I have read, you cannot just get ARP 2000 bolts for these rods. They are considered an upgrade so, it seems like there is some truth in not having to get the rods reconditioned but I will give Manley a call just to make sure. I know my machinist builds a lot of Indy motors which if there is anything more expensive than a Ford that would be it.

 

[Sleepinbeauty]

I called up Manley and they are saying that the rods should be resized which would naturally make sense.

I'm assuming the 347 is a stroked 302. Even the stock fox body 302s wouldn't touch twenty mpg from the people I've known that had them. Now, my lightweight 02 Z06 ( 3116 lbs) with a six speed gets pretty close to thirty and displays as much as 35 mpg on the interstate if the gauge cluster can be considered accurate. Also, why the hell would you care about gas mileage. I never get more than 10 average when I drive the Z06.