L26 with MN47 Head

[at-jefft]

Im trying to get information on swapping my e88 to maxima 47 ( mn47 ) head. What would be the final CR? (felpro or nissan. Would this run on pump gas? I think we get 93 in IL. I drive my Z daily for 3 months of the year.

 

Thanks, Jeff

[T-Bone028]

http://www.atlanticz.ca/zclub/techtips/calcs/engine%20builder/index.html

 

Link should give you a good idea of what type of combos produce what.

 

EDIT: My mistake, just realized this is for the L28 only.

Edited April 14, 2010 by T-Bone028

[burninator]

I tried calculating it the best I could using this engine calculator: http://www.atlanticz.ca/zclub/techtips/calcs/engine%20builder/index.html and this one: http://www.ozdat.com/ozdatonline/enginedesign/

 

Neither calculator would let me put in the exact engine combo with the MN47 head, but I typed in some of the info manually (copied from one calculator to the other when applicable).

 

Doing that the AtlanticZ calculator gave the L26/E88 combo a static compression of 8.14:1 and the Ozdat gave it 8.256:1

 

The L26/MN47 AtlanticZ gave 8.97:1 and Ozdat gave it a 9.11:1 static compression ratio.

 

I think either way its probably streetable on pump gas. But don't take my word for it, play around yourself and research the knock sensitivity of these heads, I think the MN47 head is high quench so will have a different tolerance for knock than the E88.

[BluDestiny]

Why are you using the L26? A full running L28 longblock can be had for $150. Just wondering...

[JMortensen]

It would work OK, but the L26 is the readheaded stepchild of the L engine series. I believe it uses dished pistons, so you can forget about the quench advantages of the MN47 head. It's not the question you asked, but I'd sell the MN47 and get a P head and put it on a flat top L28 and do the shim/shave .080" thing if you're spending money. If you're not spending money, it will work just fine, just won't be particularly spectacular as far as power goes.

[at-jefft]

It would work OK, but the L26 is the readheaded stepchild of the L engine series. I believe it uses dished pistons, so you can forget about the quench advantages of the MN47 head. It's not the question you asked, but I'd sell the MN47 and get a P head and put it on a flat top L28 and do the shim/shave .080" thing if you're spending money. If you're not spending money, it will work just fine, just won't be particularly spectacular as far as power goes.

7cc dish on the l26 pistons

 

I have heard of the shim/shave thing, I thought removing the cam towers would screw up the factory alignment though?

[Noddle]

I have heard of the shim/shave thing, I thought removing the cam towers would screw up the factory alignment though?

 

if you shave the head, the shims fit under the cam towers to keep the 'factory alignment'

 

Nigel

[Leon]

if you shave the head, the shims fit under the cam towers to keep the 'factory alignment'

 

Nigel

 

I believe he means longitudinal alignment, as in all the holes line up so the cam doesn't bind, not vertical. Even then, there is a method to getting all the towers on correctly. Scribing where all the towers are before removal is helpful. It should all be there if you do a good search.

[Noddle]

I believe he means longitudinal alignment, as in all the holes line up so the cam doesn't bind, not vertical. Even then, there is a method to getting all the towers on correctly. Scribing where all the towers are before removal is helpful. It should all be there if you do a good search.

 

you mean 'tag' (centre punch ) each tower, so they go back in the same place ?

 

as you do with the main caps and conrods ..

Edited April 16, 2010 by Noddle

[Leon]

you mean 'tag' (centre punch ) each tower, so they go back in the same place ?

 

as you do with the main caps and conrods ..

 

Yes, a mark that shows the alignment of the caps with the head.

 

Here is a quick search result: http://forums.hybridz.org/index.php?/topic/79242-can-the-hole-in-the-cylinder-head-for-the-cam-tower-bolt-be-repaired/page__p__752837__hl__removing%20cam%20towers__fromsearch__1entry752837

 

Link from resulting thread: http://community.ratsun.net/index.php?showtopic=10760

[JMortensen]

you mean 'tag' (centre punch ) each tower, so they go back in the same place ?

 

as you do with the main caps and conrods ..

If I recall correctly you can't flip them around, but you can mark them 1, 2, 3, 4, 5 so they go back in the same spot. They don't require line boring or anything like that. You can take them off, shim them up and there are no ill effects from doing so unless you really don't pay attention to what you're doing. Put the cam in, make sure it spins freely before hooking up the timing chain, and you're good to go.

[at-jefft]

http://www.zdriver.com/forums/showpost.php?p=190230&postcount=7

 

misinformation?

[Noddle]

http://www.zdriver.c...230&postcount=7

 

misinformation?

 

If you put the cam tower back in the same place you removed it from, and the contact area on the bottom of the tower and head are clean,

and torqued correctly, you dont need to do anything else,

but if you dont put the cam towers in the same location, you may have issues with binding.

 

I always center punch the number where the towers live, ie , 1 mark on the fist tower, 2 marks on the second tower, etc,

 

Nigel

[Tony D]

http://www.zdriver.com/forums/showpost.php?p=190230&postcount=7

 

misinformation?

 

Absolute, total and positive bullshite. This goes to show that a high post count doesn't necessarily mean you know what you're talking about. That is some anal bloviation in that post. First class fertilizer!

 

In fact, if I'm in a junkyard, and see a good cam it's easier for me to simply undo the towers and take the whole thing---I've several heads from Japan that had been milled top and bottom for true, and the towers have gone missing, so 'spare towers are a good thing'!

 

If they are welded to repair the bearing surfaces (?!) you could line-bore them to restore an individual tower. Or if they had bearing inserts added (?!?!?) you could line bore them...

 

But knocking them around with a mallet will get your alignment juuuust fine. Been doing it for 20+ years without incident. And this is not a 'screwing your sister' example, either!

 

If the towers were so critical....how do you correct top of cylinder head warpage? Replace the head with a new assembly????????? This is common machine / millwright practice here, nothing rocket-science level involved. Apparently the poster hasn't actually come out of mom's basement to work on an L-Head in the real world...

[JMortensen]

Tony is right, both in terms of swapping the towers and that post count means nothing. I swapped cam towers from a P79 if memory serves when I added a cam to my E31 head because I had an internally oiled cam and a spray bar head, and I wanted to run the right towers for the oiling system. Now I realize that with the pump I had I should have just left it and used both oiling systems, but I ran that head with that cam for many years as a daily driver and had no problems. Like I said, make sure it spins freely. That means that you're in alignment and good to go.

[Daeron]

Thanks guys, you've supplied me with ammo that I may or may not need. (Regarding definitive answers on cam tower re use and transplant.)

Edited April 23, 2010 by Daeron