Please Tell Me What You Think of This Build

[Challenger340]

Okay, I measured the current lifter preload on all the right side push rods and they all average .170" except one oddball was .100". That would be .110"-.150" too much preload! Yikes!

I have the left side head off, so I didn't measure that, but I would imagine it to be about the same.

As stated, they are 9.31" stock rods, so I assume the block/heads must have been milled? Am I wrong in assuming this? Could there be another cause?  

Also, I noticed that the exhaust valves sit about .070" higher than the intake valves. This may complicate finding final pushrod length?

Now you have the Heads off, you can do some basic measurements.....
The Pistons being .085" down the Holes @ TDC, is consistant with the 1.99" Compression Distance for those Pistons, and pretty much confirms NO Block Milling has been done, or VERY little if any at all......
and from your Pictures....
I suspect NO Head Milling either ?
But,
you can go measure the Head Chambers over on the Flat side away from the Valves. Should be around .095" to .100" Deep on a stock "un-milled" 906 Casting.
Measure a few, over at the far edge, just in, and average.

BEST, would be to do an actual "CC" measurement on a Chamber(2), to know the Volume for sure, but again from your photos, it appears to me as if the Valves are well sunk in the Chambers(Exhaust especially),
which causes the Valve 'tips" up top, to extend further OUT of the head, and could be your lifter Preload problem ?
You following me here ?
The more the Valve Seats are ground down, where the Valve "Head" sits, the more the TOP of the Valve sticks higher, making the pushrods too long....


Further,
All Valve "Tip" Heights on the Top, should be the SAME within .010-.015" on a GOOD Valve Job, and if I remember correctly, should measure within 1.97" as high as 2.040" for correct stock Height, from the Spring Seats to the Valve Tip, to provide adequate Lifter preload using stock length Pushrods on un-milled Block & Heads.
So, if you can go measure the distance from the Valve Tips down to where the Springs sit on the Head, you'll get an idea "how" sunk the valves are, which kills Flow, and adds Chamber Volume....

If the Flat Portion of your Head Chambers is around the mentioned .100", and from your Photos, looks like those Valves(exhaust) are gone to China, you may well be at 92 CC Heads, and about 8.75:1 with the steel shim head gasket.
Not great, not the end of the World.....
IMO,
you then have some decisions to make......

* Go see how equal your valve tip heights are.....and how HIGH from the bottom where the Springs sit...
* Go measure the depth of the "Flat" portion of your chambers....

[firefighter3931]

Bob brings up some good points about the valve seats ; your valves look sunk so that will make the installed height too tall and throw off the lifter pre-load.

I'm allways assuming that the heads on any build are fresh & good to go.....this isn't the case with the build in question, unfortunately. 


Ron

[bobs66440]

Okay, here goes.

The depth of the chambers (on the flat area) on the head I have off is:  .075 - .075 - .082 - .087
It looks like there was some polishing going on there which may account for the differences.

The valve stem heights from the tips to the machined part where the bottom retainer sits: exhaust avg. - 2.240     intake avg. - 2.190.

You can see from the pics how ragged they are.

[Challenger340]

BINGO !
There is your Lifter preload problem solved, the Valves are sunk too far in the Heads for the stock Non-Adjustable Valvetrain.
You'll need an Adjustable Valvetrain Rocker Arm setup, and new Pushrods to make those Heads work....
IMO,
with the poor Flow they would have with the SUNK Valves, NOT worth it.....

Again IMO.....
BEST Bet, is go buy some "properly" rebuilt CLOSED Chamber Heads, with correct valve tip Heights.....
2 benefits..
BUMP your compression up to a useable range for Cams you are looking at....
Be able to re-use your existing Rockers/Pushrods on Heads with correct Tip Heights, and have correct lifter preload...

[bobs66440]

BINGO !
There is your Lifter preload problem solved, the Valves are sunk too far in the Heads for the stock Non-Adjustable Valvetrain.
You'll need an Adjustable Valvetrain Rocker Arm setup, and new Pushrods to make those Heads work....
IMO,
with the poor Flow they would have with the SUNK Valves, NOT worth it.....

Again IMO.....
BEST Bet, is go buy some "properly" rebuilt CLOSED Chamber Heads, with correct valve tip Heights.....
2 benefits..
BUMP your compression up to a useable range for Cams you are looking at....
Be able to re-use your existing Rockers/Pushrods on Heads with correct Tip Heights, and have correct lifter preload...

I agree, thank you for all your help!  

Based on the measurements of the chambers, would you say they have been milled?

[Chryco Psycho]

installing hardened seats & or larger valve can even the height if you are partial to those heads fro some reason

[BSB67]

Well, it looks like the guy that sold you the engine was consistant....he misrepresented virtually everything.  It is a stock 5 qt. oil pan too.

If you cannot afford Stealth heads or similar, I'm at a loss at what you can do that would make any measurable difference that would not be throwing good money after bad. If the valves can close, just slap it together, hope for the best, and know that mini vans will probably spank you, or wait until you have enough money top put a decent top end on it.  Do you need to do something now?  Can it wait a year until you have more funds?

I think the unfinished chambers are about 0.090" IIRC.  Measure the thickness of the short bolt boss...uncut they are 1.000 +/-.  Based on the head-intake fitment, I doubt they were cut much, and not since they were run last.

[Challenger340]

The Heads have probably undergone some routine surfacing throughout their career in rebuilding, but with those measurements, I would not say it was any kind of targeted "Milling" for Chamber size reduction.
Also IMO,
it is simply not cost effective to persue any type of rebuilding processes to "repair" those heads with larger Valves/New Seats, as you would quickly exceed the Price of purchasing better non-WRECKED good iron replacement castings, or even new Stealths etc., etc.
Sorry, but imo, those are metal bin candidates.....

I certainly hope for your sake, that the quality of Head rebuilding exhibited there, is NOT reflective, of what has been done internal of the rest of the Engine ?

Again IMO.....
BEST Bet, is go buy some "properly" rebuilt CLOSED Chamber Heads, with correct valve tip Heights.....
2 benefits..
BUMP your compression up to a useable range for Cams you are looking at....
Be able to re-use your existing Rockers/Pushrods on Heads with correct Tip Heights, and have correct lifter preload...

Some 516/915 CLOSED Chamber castings from Aerohead, may be the most cost effective solution at this point ?

[bobs66440]

BEST Bet, is go buy some "properly" rebuilt CLOSED Chamber Heads, with correct valve tip Heights.....
2 benefits..
BUMP your compression up to a useable range for Cams you are looking at....
Be able to re-use your existing Rockers/Pushrods on Heads with correct Tip Heights, and have correct lifter preload...

Some 516/915 CLOSED Chamber castings from Aerohead, may be the most cost effective solution at this point ?

I agree and I think that's what I will do.

Regarding the rest of the engine, is there an easy way to tell if it wasn't butchered?

[Challenger340]

BEST Bet, is go buy some "properly" rebuilt CLOSED Chamber Heads, with correct valve tip Heights.....
2 benefits..
BUMP your compression up to a useable range for Cams you are looking at....
Be able to re-use your existing Rockers/Pushrods on Heads with correct Tip Heights, and have correct lifter preload...

Some 516/915 CLOSED Chamber castings from Aerohead, may be the most cost effective solution at this point ?

I agree and I think that's what I will do.

Regarding the rest of the engine, is there an easy way to tell if it wasn't butchered?

If you mean without dis-assembly and inspection....not really...

I would suggest running the Oil System on a primer Rod BEFORE installation.......with a Mechanical Oil Pressure gauge attached......see what Oil pressure presents....
and watch when you stop, to see how "fast" it drops, or "Avalanches", as a reference to total clearances internal....

* 10W30 Oil at 70*F is a good reference for baseline pressure readings to comparables.....and whether a High Volume or std volume pump....

[bobs66440]

I removed the oil pan (which, btw will not work on my car. It's for a C-body -933  ) and checked the side clearance of the rods. The book calls for.009-.017. These are .017/.018/.018/.022. Do you think this will be a problem?

Also checked the crank end play. It's .004, so that should be ok.

Everything else looks pretty clean. New cam, lifters and double chain timing set, plus a 440-Source billet rear main seal cap.

[Challenger340]

Nope, that will be FINE on the Rods...probably even a good thing...throws more Oil up to lube the Piston Pins which depending upon the Rod Bearings... May, or may-Not have Oil squirt holes.

.004" is a little on the tight side for my preferences on end play, especially with a 4 spd ? But well within specs !
and,
depending how much force you applied when reading ? probably just fine also....

Finally ! Some good news !
(I was beginning to feel like an goof, always saying BAD stuff !)
Looks promising from here.....

[bobs66440]

depending how much force you applied when reading ? probably just fine also....

What do you mean? I pried the crank forward & back until it stopped with a screwdriver like the book says.