I think the fact that you are ProCharged helps.

quote:

Originally posted by seabass:
my donovan block is 6 years old the best I remember and works great...

JR, does it have steel or billet aluminum Main cap? David Reher told me most all his big inch nitrous motors have splayed billet aluminum caps. He said it eliminates a majority of the cap walk issue. It also eliminates the material transfer of the aluminum to steel caps if they do move. But were also talking a solid block not water

Pretty sure its iron caps. https://donovanengines.com/engine-blocks/

Boost does not kill,bad tune up kills. Boost will shorten life span due to more power. Biggest issue with roots is strain on end of crank from power required to spin roots. I know the older hi helix 14-71 took 300 to 400 hp to spin them. Now that was 50 to 60% od.

Aluminum block are plenty strong. Yes Hemi block are lot stronger bottom end due to design of Y block. As I have heard thousand times only reason Chevrolet could not run in TF is crank is hanging out bottom like dead weight. This came from Alan Starr one of the last to run Chevrolet in TF. He told me if I had any sense I would have switched to Hemi lot earlier and saved a ton of money.

Aluminum caps are used I alot of motors as upgrade from iron. I know parks makes them for SBC for Jr. fuel guys.WHile not on boost and not taking the hammering a blower adds they work great.

Everything has a limit and that is why god made Hemi's. When your stuff breaks step up into the world engineered to be abused parts. While BBC and SBC have decades of engineering for dependable power in moderate range .The Hemi stuff has been engineered to huge power and live, well with TF maybe live until crew chief figures out where to get and cpl hundered HP.

Chris, I stand by my statement that boost kills, a bad tune-up and boost will make that much worse. I also agree the a Roots blower puts tremendous stress on the front of the crank. If you look at the design of a Roots blower you can see that the power it takes to drive it is not a steady, even load but a pulsing load because of the rotor design whereas the ProCharger is much more of a even, smooth load. I liken the load the Roots blower puts on the crank as being similar to tire shake (to a lesser degree) and we all know what that does to drivetrain parts..........

The cross bolted mains of a Hemi are the main thing that makes the bottom end so strong, Chevy type blocks like the CN with cross bolted mains or New Century are just as strong on the bottom end. If you are planning 30# boost or more, go with something that has cross bolted mains.

Take a look at all the late model OEM engines like the LS, Ford EcoBoost and Coyote, Gen 3 Hemi, some of these make very good power right from the factory, they all have cross bolted mains. There is a reason for that........

This message has been edited. Last edited by: "The Bender",

quote:

New Century are just as strong on the bottom end. If you are planning 30# boost or more, go with something that has cross bolted mains.

great idea brian but guys are telling me they where told a year to get a new block from new century

How much money do you need to spend to just go 6.10? If money isn't a factor just knuckle down and buy a AJPE 481X or a BAE aluminum block, crank up the boost and hang on. Either will easily live.

Bob

quote:

Originally posted by jenavet:

quote:

New Century are just as strong on the bottom end. If you are planning 30# boost or more, go with something that has cross bolted mains.

great idea brian but guys are telling me they where told a year to get a new block from new century

That IS the problem with New Century.......

quote:

Originally posted by RPROGAS:
How much money do you need to spend to just go 6.10? If money isn't a factor just knuckle down and buy a AJPE 481X or a BAE aluminum block, crank up the boost and hang on. Either will easily live.

Bob

Yup.

IF I were to do it again a CN billet or a 481X would be my choice. Probably the 481X....

I was pitted next to Mike Coughlin at the last Lucas Series race held at ETown....2017 I think...

He had a Pro Charged Pro Line engine and yes it was one Bob and others mentioned. I looked it over real good and it was impressive....

He could go 6.0's with ease and dialed it to run around 6.05 that weekend and might have won, I don't really recall....

Of course $$ is no object for that team......

I watched them warm it up and do routine work all weekend and there was no big deal of any kind....he did have a crew of a few guys...

Al Kenney was there at one point and he told me they could make as much as 4500 hp with those engines.....

The Pro Charger may not be as favored as it was since I see more conventional blowers on cars but I assume it's just what the racer chooses to work with for his racing program....and probably his budget...

Mike Coughlin has since switched to a roots blower with EFI

Like I said earlier, the AJPE 481X is basically a Hemi with GM style canted valve heads

"Mike Coughlin has since switched to a roots blower with EFI"

That is partly why I said the Pro Charger may have some issues to deal with....

Al Kenney runs a roots blower as well...

mike told me they couldnt get any consistency out of that combo especially with any weather swings.I think the electronic injection is much more moody than a blow through carb

quote:

Originally posted by "The Bender":
Chris, I stand by my statement that boost kills, a bad tune-up and boost will make that much worse. I also agree the a Roots blower puts tremendous stress on the front of the crank. If you look at the design of a Roots blower you can see that the power it takes to drive it is not a steady, even load but a pulsing load because of the rotor design whereas the ProCharger is much more of a even, smooth load. I liken the load the Roots blower puts on the crank as being similar to tire shake (to a lesser degree) and we all know what that does to drivetrain parts..........

The cross bolted mains of a Hemi are the main thing that makes the bottom end so strong, Chevy type blocks like the CN with cross bolted mains or New Century are just as strong on the bottom end. If you are planning 30# boost or more, go with something that has cross bolted mains.

Take a look at all the late model OEM engines like the LS, Ford EcoBoost and Coyote, Gen 3 Hemi, some of these make very good power right from the factory, they all have cross bolted mains. There is a reason for that........

Exactly my point. Why spend butt loads to make something that has weaker design better. You could build Hemi of engine with same design bottom end and maybe spend more initial out lay but be ahead in the long run. As stated the reason chevy never made it in top fuel was bottom end deign and lack of crank support.

While I do believe chevy motor is great and that would be hard to argue. When it comes to heavy boost numbers its harder to argue against that it lacks strength in bottom. It does have better valvetrain design than Hemi especially oiling wise.

The chevy top end with hemi bottom end is probably best deal,unless you are tearing down between rounds, chevy sucks here. Need dzus on headers to allow access to head bolts.LOL

Bad thing I have the Hemi and all the parts to run blower except blower(intake,injector,pumps pulleys and brackets out the azz) and the cash. Last one fixes everything/

quote:

Originally posted by jenavet:
mike told me they couldnt get any consistency out of that combo especially with any weather swings.I think the electronic injection is much more moody than a blow through carb

Why not a blow thru injection setup? MFI not EFI. Something like terminator. I do see issue with pressure and closing throttle if running lot of boost,maybe not.

quote:

Originally posted by wideopen231:

quote:

Originally posted by jenavet:
mike told me they couldnt get any consistency out of that combo especially with any weather swings.I think the electronic injection is much more moody than a blow through carb

Why not a blow thru injection setup? MFI not EFI. Something like terminator. I do see issue with pressure and closing throttle if running lot of boost,maybe not.

Bruce Mullins is running that system right now.....

quote:

Originally posted by jenavet:
mike told me they couldnt get any consistency out of that combo especially with any weather swings.I think the electronic injection is much more moody than a blow through carb

From my experience the EFI has been better for consistency

If I had the time and money to figure it out I would put EFI on my blower motor, there is several that I know of in TD and they are very consistent, Bob Button has 4 EFI Brad Anderson blown Hemis and those cars are deadly.

Question; what firing order are you guys running? The fuel guys running 4/7/2/3 swap to help the crank load?