Racer X
SHO Pilot, Retired
If your hot idle oil pressure is 10psi or more, you're ok.
Engine Build Questions
- Thread starter pitaSHO
- Start date
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pitaSHO
Why do I do this to myself?
Block and balanced rotating assembly (micropolilshed crank), both cleaned really well, are back in my shop. Now for some assembly ****, main bearings, and some time...
Parts currently on hand and ready to go in
* Brass freeze plugs
* Jet hot coated oil pan
* Lower gasket kit (Ford front and rear main seals)
* New rod bearings
* New rings
* New water pum9
* Crank sensor
Chris K.
Parts currently on hand and ready to go in
* Brass freeze plugs
* Jet hot coated oil pan
* Lower gasket kit (Ford front and rear main seals)
* New rod bearings
* New rings
* New water pum9
* Crank sensor
Chris K.
pitaSHO
Why do I do this to myself?
OK. In regards to honing the cylinder walls (not trying to beat a dead horse) what is the main argument against it? Is it seating the rings? Cylinder walls out of spec? When I picked up the block on Friday my engine builder told me he went ahead and honed the walls, and they look nice! He told me the main reason it would be suggested that I don't hone the walls is because of the technique used in seating the rings that can result in a motor that will always burn oil and never seat the rings. He said you always want to hone the walls, so he did it without charging me for it. I've already re-read all the other responses in this thread, so I don't need a re-hash of those things.
1. The rings don't seat.
2. The cylinders may be out of spec.
So if I do the install correctly, and the cylinders are still in spec, it seems that it should be fine...
Chris K.
1. The rings don't seat.
2. The cylinders may be out of spec.
So if I do the install correctly, and the cylinders are still in spec, it seems that it should be fine...
Chris K.
I only suggested not honing if you re-use the original rings in the same cylinder when reassembling, since they are already seated - assuming you can still see the factory cross-hatching, which is typically the case. if new rings are used, a light hone would be good.
fwiw, I also notice on the SHO engines, the factory angle on the honing cross-hatch marks is more like 60* than the 90* that people typically say to do.....
fwiw, I also notice on the SHO engines, the factory angle on the honing cross-hatch marks is more like 60* than the 90* that people typically say to do.....
I was taught the same way.
You have probibly never rebuilt an engine with this kind of metal quality.
You can hone all you want, but if it ends up burning oil, that's on you.
Last edited:
Lorenr
Member
Re-Ring, Don't Hone
Chrysler engineering did a bunch of work on this in the seventies.
They found out that each time they pulled the pistons and added NEW rings, the motor made more power. They usually found about 15-20 horsepower total up to the third set of rings. No new horsepower after that. However, the power did stay there.
They reasoned that the rings were conditioning the cylinder walls, but sacrificing themselves in the process. They used a reasonably fine hone as was the accepted practice at the time. I think around 400 grit.
If the cross hatch is still evident (it should be) and you are reusing the same undamaged pistons, just add new rings. I can't believe there is more power boring, honing and adding new pistons.
:swing:
Chrysler engineering did a bunch of work on this in the seventies.
They found out that each time they pulled the pistons and added NEW rings, the motor made more power. They usually found about 15-20 horsepower total up to the third set of rings. No new horsepower after that. However, the power did stay there.
They reasoned that the rings were conditioning the cylinder walls, but sacrificing themselves in the process. They used a reasonably fine hone as was the accepted practice at the time. I think around 400 grit.
If the cross hatch is still evident (it should be) and you are reusing the same undamaged pistons, just add new rings. I can't believe there is more power boring, honing and adding new pistons.
:swing:
pitaSHO
Why do I do this to myself?
Thanks, Brian. I'm still undecided as to what to do, but I have enough info and input now to continue. Thanks again for your input. Dead horse now dead.
Chris K.
Chris, consider bronze valve guides, or at least replace the ones you have with stock style. The cast iron stockers don't last forever (as I've learned on my original owner 95).
While you are at it, replace the guides with ones that taper near the valve seat, this will help cylinder flow (stockers are square cut). Consider swirl polishing the stock valves if you are reusing (will reduce gunk buildup).
While you are at it, replace the guides with ones that taper near the valve seat, this will help cylinder flow (stockers are square cut). Consider swirl polishing the stock valves if you are reusing (will reduce gunk buildup).
pitaSHO
Why do I do this to myself?
The stock valve guides are pretty robust. I've never heard of one breaking. My only plans for the heads are a hot tank cleaning, new valve stem seals, and Tri Flows, but I like the idea of cleaning the valves so they don't collect gunk.
The guides don't break, they wear out, allowing oil to seep down and the crankcase and intake runner to communicate with each other. Yes fresh valve seals will help but they aren't designed to be the primary sealing mechanism.
Your engine builder likely has special pin gauges and can show you where they are vs the original specification. Especially check the exhaust guides (more heat = more wear).
Your engine builder likely has special pin gauges and can show you where they are vs the original specification. Especially check the exhaust guides (more heat = more wear).
pitaSHO
Why do I do this to myself?
Is it OK to cross used valves with new guides? The only new guides available are oversized, and I'm not going to go there; too much money, but I could spring for new guides since I'm already in there.
As long as the used valves mic up above the minum diameter you are fine to use used valves with new guides. I think what you found were guides with an oversized OD, not ID. The old guides get pressed out, and then somteimes reamed to get an exact fit for new guides.
Here is another source for bronze valve guides:
http://www.sivalves.com/ocdomestic_vguides_ford.html
Finally, if I consult some catalogs at home I should be able to find you a couple of part numbers for iron guides, which will be cheaper than bronze.
Here is another source for bronze valve guides:
http://www.sivalves.com/ocdomestic_vguides_ford.html
Finally, if I consult some catalogs at home I should be able to find you a couple of part numbers for iron guides, which will be cheaper than bronze.
pitaSHO
Why do I do this to myself?
No problem. That gives me the info I need for now. I'm still a ways from doing the heads, so I have some time to look it over.
on the 185k motor I am currently rebuilding, there is no noticable wiggle on the valves - the guides are not worn. but the seals are toast - in fact some of the exhaust seals were missing the garter spring! so its no wonder that it burned a little oil.
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