Oil Pump not machined with block help. - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

KaminaSan · 01-03-2011, 04:36 AM

So here is the deal.
I bought a built short block about a week ago from a user on here(nochain), however it seems that the block was not decked with the oil pump.

Meaning the oil pump is sitting maybe 1/4 cm higher than the block itself. I was told by my mechanics at pit garage that the headgasket would not seat if left like that, and that the only thing to do is completely take out all the pistons/rods/crank and have the block redecked with the oil pump(which I would buy a brand new one.

What I'm wondering, is, is it possible for a machine shop to just take measurements, pull off the pump, and machine it, or does it 100% for sure have to be stripped down to the bare block and redecked?

I feel bad because the previous person I bought it from paid 900+ in machine labor/building, and now we are gonna have to rip it all apart.

Thoughts?

BiG MiKE86 · 01-04-2011, 08:46 PM

ur gonna feel worse when you have to pull all apart if the headgasket doesnt seal correctly... I'd say pull it apart and have em both machined together. Putting a block together correctly isnt rocket science goodluck

nieko · 01-05-2011, 01:57 AM

IMO

The front timing cover is a low oil pressure zone. i put gasket maker on the front cover along with the headgasket.

I was a noob and had my block decked, and then bought a new oil pump.

it was baerly taller than the block itself.

My headgasket sealed fine.

Not saying yours will.. but mine had no problems.

codyace · 01-05-2011, 09:08 AM

The headgasket itself will seal without issue around the cylinders...however that front cover may seep/leak a bit , even with sealer like the FSM says to apply upon that front bead area.

I wouldn't loose to much sleep over it...if you paid good money to have the bottom end assembled, I'd slam the rest together, seal that front lip up, and ship it.

180wanabe1 · 01-05-2011, 12:09 PM

if they can't measure it and machine it without doing the block then i would find a new machine shop cause they suck. or if you can get a precise measure of how much over it is then just give them that and tell them to machine off that amount but it needs to be to like a thousandth of an inch. i had my ka block decked years ago without the pump and the only problem it cause was that that it pushed the top cover up and the dizzy didn't slide right in like its supposed to but i made it work.

KaminaSan · 01-05-2011, 01:15 PM

Quote:

Originally Posted by codyace

The headgasket itself will seal without issue around the cylinders...however that front cover may seep/leak a bit , even with sealer like the FSM says to apply upon that front bead area.

I wouldn't loose to much sleep over it...if you paid good money to have the bottom end assembled, I'd slam the rest together, seal that front lip up, and ship it.

This is what I was thinking,it's not a HUGE difference, but there IS a difference. It's gonna cost three hundred to get it all redone, having my mechanic take everything apart, remeasure, and have it redecked.

I just honestly don't know how a machine shop wouldn't require the oil pump to be blocked at the same time, so that's why I'm willing to pay the extra three hundred to have it all re-measured and clearanced.

If they skipped out on machining the pump, who knows the quality of the rest of the work they did...

codyace · 01-05-2011, 04:15 PM

Quote:

Originally Posted by 180wanabe1

if they can't measure it and machine it without doing the block then i would find a new machine shop cause they suck. or if you can get a precise measure of how much over it is then just give them that and tell them to machine off that amount but it needs to be to like a thousandth of an inch. i had my ka block decked years ago without the pump and the only problem it cause was that that it pushed the top cover up and the dizzy didn't slide right in like its supposed to but i made it work.

It's not as easy as takign the pump off and having it cut...there is enough play in each of those bolt holes that secure it to make enough difference to negate any maching done, or make it worse.

In the end, the proper way is to have it all checked out properly and have it resurfaced/checked. In reality, the HG will still seal the combustion chamber, and sillicone on that front lip would be more than enough.

nieko · 01-06-2011, 02:58 AM

Yup, I have had 0 problems.

And maybe I am wrong...

But in the FSM it does not mention anything about making sure it is decked with the block, or not too tall or anything like that either. Usually they mention little things like that.

Davidna2fi · 01-06-2011, 05:06 PM

My machine shop always asks for any front covers for the head or block, regaurdless if its a KA or SR. Best thing to do is bolt it up, and then with a marker just measure the height, also if its that noticable of a difference in deck clearance on the oil pump, your timing will be off for sure since the head is closer to the block. But take a pic of the clearance and post it up. The small alignmnet dowels on the block on the front cover make it fit very snug and perfect, you can take the oil pump to benchtop belt sander to knock most of the material off, and then smooth it out until its either at or below the deck surface. Do not let it go above the deck surface at all, better to have it sit below slightly, RTV will take up the gap in that area.

codyace · 01-06-2011, 09:50 PM

Quote:

Originally Posted by Davidna2fi

My machine shop always asks for any front covers for the head or block, regaurdless if its a KA or SR. Best thing to do is bolt it up, and then with a marker just measure the height, also if its that noticable of a difference in deck clearance on the oil pump, your timing will be off for sure since the head is closer to the block. But take a pic of the clearance and post it up. The small alignmnet dowels on the block on the front cover make it fit very snug and perfect, you can take the oil pump to benchtop belt sander to knock most of the material off, and then smooth it out until its either at or below the deck surface. Do not let it go above the deck surface at all, better to have it sit below slightly, RTV will take up the gap in that area.

Ahy my dumbass did forget about the dowel pins, what the hell was I drinking when I wrote that last night! I thought it was just Cofffee haha!

Again, if they are taking 'that' much material off as you said, there will be more to look at than a marginal front cover difference that's for sure.

01-04-2011, 08:46 PM	#2
BiG MiKE86 Nissanaholic! Join Date: Mar 2007 Location: Ft. Lauderdale Age: 38 Posts: 1,776 Trader Rating: (12) Feedback Score: 12 reviews	ur gonna feel worse when you have to pull all apart if the headgasket doesnt seal correctly... I'd say pull it apart and have em both machined together. Putting a block together correctly isnt rocket science goodluck __________________

01-05-2011, 09:08 AM	#4
codyace Post Whore! Join Date: Dec 2004 Location: Poconos, PA Age: 39 Posts: 8,030 Trader Rating: (58) Feedback Score: 58 reviews	The headgasket itself will seal without issue around the cylinders...however that front cover may seep/leak a bit , even with sealer like the FSM says to apply upon that front bead area. I wouldn't loose to much sleep over it...if you paid good money to have the bottom end assembled, I'd slam the rest together, seal that front lip up, and ship it. __________________ *Want Air Conditioning in your SR20 Swapped car? Check out www.sr20acbrackets.com for more information! Quest Alternator Conversions for SR20!* Check my Group Buy! Tired of lousy internal gates? Go external wastegate with one of my manifolds, Check out my group buy

01-05-2011, 01:57 AM	#3
nieko Post Whore! Join Date: Sep 2007 Location: Westminster Age: 33 Posts: 2,695 Trader Rating: (14) Feedback Score: 14 reviews	IMO The front timing cover is a low oil pressure zone. i put gasket maker on the front cover along with the headgasket. I was a noob and had my block decked, and then bought a new oil pump. it was baerly taller than the block itself. My headgasket sealed fine. Not saying yours will.. but mine had no problems.

01-05-2011, 12:09 PM	#5
180wanabe1 Zilvia Member Join Date: May 2006 Location: wa Posts: 188 Trader Rating: (2) Feedback Score: 2 reviews	if they can't measure it and machine it without doing the block then i would find a new machine shop cause they suck. or if you can get a precise measure of how much over it is then just give them that and tell them to machine off that amount but it needs to be to like a thousandth of an inch. i had my ka block decked years ago without the pump and the only problem it cause was that that it pushed the top cover up and the dizzy didn't slide right in like its supposed to but i made it work.

01-06-2011, 02:58 AM	#8
nieko Post Whore! Join Date: Sep 2007 Location: Westminster Age: 33 Posts: 2,695 Trader Rating: (14) Feedback Score: 14 reviews	Yup, I have had 0 problems. And maybe I am wrong... But in the FSM it does not mention anything about making sure it is decked with the block, or not too tall or anything like that either. Usually they mention little things like that.

01-06-2011, 05:06 PM	#9
Davidna2fi Zilvia Junkie Join Date: May 2008 Location: Houston, TX Posts: 513 Trader Rating: (18) Feedback Score: 18 reviews	My machine shop always asks for any front covers for the head or block, regaurdless if its a KA or SR. Best thing to do is bolt it up, and then with a marker just measure the height, also if its that noticable of a difference in deck clearance on the oil pump, your timing will be off for sure since the head is closer to the block. But take a pic of the clearance and post it up. The small alignmnet dowels on the block on the front cover make it fit very snug and perfect, you can take the oil pump to benchtop belt sander to knock most of the material off, and then smooth it out until its either at or below the deck surface. Do not let it go above the deck surface at all, better to have it sit below slightly, RTV will take up the gap in that area.