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View Full Version : Diff in 5.7 vs 6.1 Hemi block ?



DRJDVM's '69
10-02-2006, 07:05 PM
Is there any difference in the design for the 5.7 and 6.1 L Hemi blocks ??

Obviously the bore etc is different and the internals etc, but I want to know if the block design is different in any way in regards to being able to handle high HP loads

I'm planning on going forced induction, so cubic inches are less of a concern. I just want to make sure the block will hold up, so if the 6.1 block is designed stronger, then its worth the extra $$. If not, I'll save my $$ and get a 5.7 and use the $$ for the internals etc.

MrQuick
10-02-2006, 10:38 PM
Is there any difference in the design for the 5.7 and 6.1 L Hemi blocks ??

Obviously the bore etc is different and the internals etc, but I want to know if the block design is different in any way in regards to being able to handle high HP loads

I'm planning on going forced induction, so cubic inches are less of a concern. I just want to make sure the block will hold up, so if the 6.1 block is designed stronger, then its worth the extra $$. If not, I'll save my $$ and get a 5.7 and use the $$ for the internals etc.

Both blocks are cast iron. The 6.1L differs from the 5.7 in the bore, block bukheads, water jackets are larger, and the 6.1L has oil squirters to help cool the pistons. 5.7L should be fine to 600hp

Check with John Buscema at XV Motorsports www.xvmotorsports.com cause they have been working with Sean Hyland on development of performance parts with the DCG build. This is a very good package. http://www.xvmotorsports.com/products/detail/index.cfm?nPID=72&cid=4&cdesc=5%2E7%2F6%2E1%20Hemi%20Engines

Right now we are experiencing a lot of 5.7L engine failure mostly due to rod bearing failures. Not sure if it is due to bearing design or connecting rod bolts as they are torque to yield. 3 last month had severe block damage.

One thing that is very important to mention is the oil system is very different from most that the cam is the last thing to get oil. The galley runs up the block thru the heads into the rocker rails then down the push rods to the lifter and then to the cam. Any leak in this area can cause engine damage. We have seen several failures after a head or head gasket replacment.

Also do not skimp on the oil pan as it does add structure. I should have another scrap block and pan in the next week if you need one for mock up.

Ron S
10-03-2006, 07:54 PM
Did you read HOT ROD's article on the 5.7 this month.A stock bottom end,with ported 5.7 heads,a cam,and a super charger made 712 hp. on the dyno.They even said,that was pushing it ,on stock rods and pistons.The 6.1 also has a forged crank,you would probably be better to start with it if you wanted to make big horse power

DRJDVM's '69
10-05-2006, 03:05 PM
My plan is definitlely to used forged internals, its just a matter of getting them with a 6.1 block or using a 5.7 block and buying forged stuff for it. The 6.1 blocks are much harder to find and quite a bit more $$ when you do find them. Especially since my plans dont really include alot of stock parts, I dont want to waste $$ on stuff that I wont be using anyway.

Yes I read the Hot Rod article and was impressed with the power but longevity in that set-up is going to be a big issue. I had alsoe read somehwere that there was potential for alot of block "flex" with power over the 500 HP range and bearing issues were also an issue.

Where are the oil squirters ?? Is this actually associated with the block or is this a separate piece that could easily be added to a 5.7 ?

My plan is to go Procharged or turbo, so I'm expecting over 600 HP and want the motor to last.

I've been looking at XV motorsports for a long time and they make nice stuff. Howerever some of their prices are out of my range.

Mr Quick.... do you work at a Dodge dealership ?? I may be interested in the 5.7 block for mock-up.... eventhough I really dont need it right now I may take you up on it while the opportunity is there...

Ron S
10-06-2006, 06:24 PM
The squirter spray the bottom of th piston from what I've read,the deep block and 6 bolt mains with cross bolts should keep the the block from flexing too much.That is one area I wouldn't worry about,its the lack of head bolts that worrys me on a forced induction hemi.Although the LS1 gm's seem to be taking it fine with the same amount. Ron

MrQuick
10-06-2006, 08:24 PM
Hey guys,
Let me know Ned and i'll bring it out with me at the next Goodguys show. Its sitting in the shop still waiting on scrap notification.
The quirters are on the bottom side of the block. Its actually a metal tube with off shoot tubes that aim towards the pistons. These motors run on the hot side also.
XV motor sports do have stud kits avaiable too. Definetly want to run forged main caps as the powdered metal ones might not cut it with boost.

Ron, big fan of your work. Did you run into any overheat problems? What temp does your run atwhile in traffic?

Ron S
10-07-2006, 04:08 AM
I'm running a BE COOL radiator and fans,which are pcm controlled,I can drive it to the track,run the car 12.400 all day and not get over 190 degrees.The pcm has the fans to come on at 160 degrees.No overheating issues at all

70B5Cuda
01-05-2012, 08:19 AM
Another consideration will be the stock valves. I believe the 6.1 has sodium filled valves so that may be a long term consideration. Aftermarket valves may not be a bad idea if using a higher mileage engine.