Cylinder Head - Competition Diesel.Com

cumins01 · 07-21-2017, 05:03 AM

I sent my 5.9 24v cylinder head out to get it looked it at. It already has a runner intake and all the other goodies. I got a call yesterday and they said it was cracked. Cracks are in the seats and go back to the injector hole. In a high hp/sled pulling application, how many guys are running cracked heads? How bad does it effect HP?

If you have to get it checked out every 2 years (freshened up), and it is cracked again, then you have to buy another head. I just don't see that being cost effective.

The plan was to fill (hard block) this one along with vlvs and some more port work.

Am planning on sending to another place just to verify. Does anyone know why they crack? Or is this a more common issue on the 4 vlv heads.

*Bodacious* · 07-21-2017, 06:23 AM

In for the info.

jasonc · 07-21-2017, 06:29 AM

Every 12v head I've seen that's been run hard is cracked to chit, doesn't seem to matter. If your filling it anyway and not running water I wouldn't worry about it, wouldn't worry about it either way.

*Bodacious* · 07-21-2017, 06:36 AM

Our 12v head exhaust seats cracked but not leaking water. Stuck it back together with no problem.

cumins01 · 07-21-2017, 06:49 AM

This is what I am wondering. If it has no effect on HP, who cares if it is cracked. So if you fill it, would you go ahead and put the larger vlvs in it and do some more P&P work? Only going on a sled pulling application. As far as I know, this head does not have press in vlv seats

95cummins5.9 · 07-21-2017, 06:59 AM

Vacuum test its, if it passes, run it. They are all cracked..

Rich dzl · 07-21-2017, 08:03 AM

24v heads can drop seats is the issue you need to be aware of . If the shop don't do a lot of cummins high performance work don't let them put the seats in .. your better off to find a shop that's does a lot of this work . nyes in Indiana is one of the best . I'm sure some one on here does head work .

cumins01 · 07-21-2017, 08:12 AM

Quote:

Originally Posted by Rich dzl

24v heads can drop seats is the issue you need to be aware of . If the shop don't do a lot of cummins high performance work don't let them put the seats in .. your better off to find a shop that's does a lot of this work . nyes in Indiana is one of the best . I'm sure some one on here does head work .

Right now it's at Scheid Diesel just because they did the work originally. They don't want me to use it and go 12 vlv. My guy doing the injectors, pistons and cam wants me to stay 24 vlv as do I. Want to be different I guess

cumins01 · 07-21-2017, 08:14 AM

Here is what they said is wrong with it.

"It has cracks thur the seat area and past the injector holes."

*EricStaab* · 08-17-2017, 10:59 AM

If it is in the injector hole it will eventually cause problems. And yes if it is cracked around the seats you could possible drop one. Even if properly installed. When the crack opens up you loose the interference on the seat. It won't always fall out right away, but eventually they loosen up.

This is why we have heads coming out for Cummins this fall and winter. We are starting with 24v heads. Solid with no water jackets first. Our results with the Duramax heads have been great. Last year we had 50 dyno passes, and 50 hooks on a set of heads. No maintenance during that duration. The heads look great when we got them back. We don't use seats in the heads, and it is two piece, so if the seats or deck are damaged we can repair them with a new piece.

07-21-2017, 05:03 AM	#1
cumins01 Name: cumins01 Title: Too Much Time Status: Not Here Join Date: Nov 2008 Location: somerville,oh Member`s Gallery Posts: 1,176	Cylinder Head I sent my 5.9 24v cylinder head out to get it looked it at. It already has a runner intake and all the other goodies. I got a call yesterday and they said it was cracked. Cracks are in the seats and go back to the injector hole. In a high hp/sled pulling application, how many guys are running cracked heads? How bad does it effect HP? If you have to get it checked out every 2 years (freshened up), and it is cracked again, then you have to buy another head. I just don't see that being cost effective. The plan was to fill (hard block) this one along with vlvs and some more port work. Am planning on sending to another place just to verify. Does anyone know why they crack? Or is this a more common issue on the 4 vlv heads.

07-21-2017, 06:23 AM	#2
Bodacious Name: Bodacious Title: Comp Diesel Sponsor Status: Not Here Join Date: Jul 2013 Location: Weston, WV Member`s Gallery Posts: 2,177	In for the info. __________________ "Careful who you argue with on the internet. Others might not know they are idiots."

07-21-2017, 06:36 AM	#4
Bodacious Name: Bodacious Title: Comp Diesel Sponsor Status: Not Here Join Date: Jul 2013 Location: Weston, WV Member`s Gallery Posts: 2,177	Our 12v head exhaust seats cracked but not leaking water. Stuck it back together with no problem. __________________ "Careful who you argue with on the internet. Others might not know they are idiots."

08-17-2017, 10:59 AM	#10
EricStaab Name: EricStaab Title: Sponsor Status: Not Here Join Date: Sep 2012 Location: WI Member`s Gallery Posts: 255	If it is in the injector hole it will eventually cause problems. And yes if it is cracked around the seats you could possible drop one. Even if properly installed. When the crack opens up you loose the interference on the seat. It won't always fall out right away, but eventually they loosen up. This is why we have heads coming out for Cummins this fall and winter. We are starting with 24v heads. Solid with no water jackets first. Our results with the Duramax heads have been great. Last year we had 50 dyno passes, and 50 hooks on a set of heads. No maintenance during that duration. The heads look great when we got them back. We don't use seats in the heads, and it is two piece, so if the seats or deck are damaged we can repair them with a new piece. __________________ No Limt MFG, Manufacturer of diesel performance engine parts: Billet camshafts, rods, valvetrain components, cylinder heads. We take on the hard and unusual jobs no one else is willing to do. Website: NoLimitMfG Facebook: Nolimitmfg Phone:715-384-4422

07-21-2017, 06:29 AM	#3
jasonc Name: jasonc Title: Too Much Time Status: Not Here Join Date: Nov 2009 Member`s Gallery Posts: 4,412	Every 12v head I've seen that's been run hard is cracked to chit, doesn't seem to matter. If your filling it anyway and not running water I wouldn't worry about it, wouldn't worry about it either way.

07-21-2017, 06:49 AM	#5
cumins01 Name: cumins01 Title: Too Much Time Status: Not Here Join Date: Nov 2008 Location: somerville,oh Member`s Gallery Posts: 1,176	This is what I am wondering. If it has no effect on HP, who cares if it is cracked. So if you fill it, would you go ahead and put the larger vlvs in it and do some more P&P work? Only going on a sled pulling application. As far as I know, this head does not have press in vlv seats

07-21-2017, 06:59 AM	#6
95cummins5.9 Name: 95cummins5.9 Title: Old man *** gossiper Status: Not Here Join Date: Jun 2012 Location: U.S.A Member`s Gallery Posts:** 4,719	Vacuum test its, if it passes, run it. They are all cracked..

07-21-2017, 08:03 AM	#7
Rich dzl Name: Rich dzl Title: 12v guru Status: Not Here Join Date: Mar 2011 Member`s Gallery Posts: 741	24v heads can drop seats is the issue you need to be aware of . If the shop don't do a lot of cummins high performance work don't let them put the seats in .. your better off to find a shop that's does a lot of this work . nyes in Indiana is one of the best . I'm sure some one on here does head work .

07-21-2017, 08:14 AM	#9
cumins01 Name: cumins01 Title: Too Much Time Status: Not Here Join Date: Nov 2008 Location: somerville,oh Member`s Gallery Posts: 1,176	Here is what they said is wrong with it. "It has cracks thur the seat area and past the injector holes."