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4g63 machine shop spec questions

Kenny_Kline

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Dec 27, 2007
Messages
789
Location
Seekonk, MA
I dropped of my 6bolt 4g63 turbo block off at the machine shop to have the following installed:

Stock crank
Eagle Hbeam rods
Wiseco 8.3:1 pistons +.020
ARP main studs

They degreased the block and magnafuxed. Installed OEM main hardware, took measurements then installed ARP main hardware torqued to 89ft lbs and it threw the mains out of round anywhere from .003-.007 tighter than OEM hardware so they line honed it back to factory spec. Next they are balancing the crank, ACT flywheel and ACT 2900 pressure plate to 0 and said they can get it within a half gram. They wanted specs from me to do the over bore and oil clearances so I gave them the following:

.0043" piston to cylinder wall clearance (torque plate being used for boring)
.0028" main oil bearing clearance
.0032" rod oil bearing clearance
.0060-.0098" rod side to side play
.005" crank thrust end play
12-20 RA finish on deck


I plan on running a 15-40 Brad Penn oil, stock oil pump on 90 straight cut gears, stub shaft, Reving to 8500-8700RPM on a PTE6266 BB turbo @ 35-40psi going for 500-600whp reliably street car but weekend warrior mostly.

I told them let me confirm the specs. I am using king tri-metal bearings on both mains and rods.

Opinions???
 

BogusSVO

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Aug 29, 2013
Messages
232
Location
Pensacola, Florida
Guess Ill speak up....

First, you may want to get your stuff back from the shop you are using if they can not read the ARP torque sheet for your main studs. The torque is 60ft/lbs with the supplied ARP blue pack moly lube.

click

and the kit instructions.

click

Now that they have align bored the block to the factory Bore housing spec at 89 ft/lbs, when torqued to the ARP torque spec, the housing bore will be loose.

Since they pulled the ARP mains to 89 ft/lbs, that is half again what the spec is, the mains studs need to be inspected for stretch.

Crank end play is good.
Bearing choice is good, I use mainly King bearings, and a fair amount of the King XP
Rod vert oil clearance is ok
main oil vert clearance, a tad too loose for my liking.
Rod side play can be loosen up a tad.
Deck finish is good, they must have a PCD cutter to get that slick
The PTW is fine, just about an extra .001
 

Kenny_Kline

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Dec 27, 2007
Messages
789
Location
Seekonk, MA
Correction the L19 on torque plate were torqued to 89ft lbs, the main studs were set to 60ft lbs. I will see what we have for crank oil clearance when we put the bearings in. Do you have a suggestion on main oil clearance and rod side clearance?
 

BogusSVO

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Aug 29, 2013
Messages
232
Location
Pensacola, Florida
Ok that makes more sense now.

First I want to say is, machinists and engine builders draw on there experience of what has worked in the past.

My rule of is .00075 -.001 for every inch of std main dia

rods is is .001 -.00125 on the rods

Rod side clearance I use on a 4g is .011 -.013

Also I do BSE on all my builds so I have a bit of "extra" oil pressure I can put to use.
 

Egalloway

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May 3, 2013
Messages
45
Location
Asheville nc
That rev range and power range sound familiar doesn't Dale?
To the OP dale knows his stuff, my .02 make sure you have the head built by Dale to hit those numbers and get a way over built trans if you are serious about that power level.
 

swe_gvr4_1991

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Jul 27, 2006
Messages
177
Location
Sweden, Alingsås
I would pass on the stub shaft it i were going to rev that high.
Have done stub shaft BSE in the past and my opinion is that if you're going for a race build get the balancer on the oil pump gears turned instead.

Like this: (Internet random pic...)

IMG_2820.jpg


I did this on my last build and i am very happy with the results. I rev to about 8k when i WOT pulls.
 

BogusSVO

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Aug 29, 2013
Messages
232
Location
Pensacola, Florida
I would agree on the use of the AMS/GSC "race shaft" Or cutting down the factory shaft.

The AMS or GSC race shaft run about $200

You should be able to have a local industrial machine shop cut down the factory shaft for about $75-$125

I follow the thought that AMS claims about the race shaft, that it helps stabilize the oil pump gears, more so the helical cut gears more so than the straight cut gears.
The race shaft will also help if the timing belt is installed to tight.

Now the draw back is, that some blocks have spun the rear BS bearing and have damaged the housing bore, if this is the case in the block you build, then you can only use the stubby shaft.

Both have been used, both have been proven over 800hp

So it comes down to if the block can run the race shaft or not.
 

swe_gvr4_1991

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Joined
Jul 27, 2006
Messages
177
Location
Sweden, Alingsås
I went with the DIY approach when manufacturing my shaft. /ubbthreads/images/graemlins/wink.gif
Cost was $0.

And yes you can see less vibration on the timing belt after doing this mod.
But this is related to the harmonics of the 4 cylinder engine. I my experience less vibration on a belt is good.

Little OT: My day time job way back was operating a 6-axis wood molding planer for 8 years going thru 100's of belts. Vibration kills belts.
 

paul j

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Apr 27, 2004
Messages
242
Location
Lone Tree, CO
My reaction was the same as BogusSVO. If the shop does not know the specs for the engine they must have no experience with the engine. Too many horror stories via Dale and others from not knowing the 4g63 engines to let them proceed.
 

Kenny_Kline

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Dec 27, 2007
Messages
789
Location
Seekonk, MA
Ive been doing the full rear shaft aka "race shaft" before it was cool. Before AMS even offered a kit I was doing it. $50 at the machine shop in a lathe and I was good to go. I did this on my galant about 7 years ago and everyone made fun of me for doing it, saying nothing wrong with stub shaft, etc.

That being said, I did buy a GSC kit for cheap and have it ready to be installed but the bearing spun in the block and wont take another bearing which is why I am running a stub shaft. I searched for 2 months for a good core 6 bolt but nothing is out there so I said screw it, stub shaft time.

Yes this machine shop doesnt have any expereince with the motor but they are just doing my machine work to the specs I tell them. I will be assembling it.
 

prove_it

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Jul 3, 2008
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Sioux Falls, SD
You sure are the man Kenny.
 

Brianawd

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Apr 18, 2005
Messages
2,117
Location
Portland OR,
The issue with running the stub shaft and having it fail was because of 2 reasons.
1st timing belt set to tight.
2nd to thin of oil used.running 20w50 helps support the gears.

The idea of the turned down shaft was nice but I have see far to many motors die because of the rear bearing going out.

I have been running the stub shaft in 4g63's now for over 12 years and have never had a pump fail. Set belt tension correctly and use 20w50 oil.

Edit also forgot that extending the oil pick up fixed a lot of the issue with pump problems. Hard launch was causing oil starvation.
 
Last edited:

Street Surgeon

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Mar 3, 2004
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941
Location
Omaha, Nebraska
I don't personally care for these "race shafts" because at 8k RPM you still have a shaft (counterweighted or machined) that's spinning at 16k! They fail because they spin bearings, and you still have a shaft spinning around in there just waiting to spin that rear bearing. I'm not a machinist but I've seen 6-bolts with A LOT of core-shift and putting one of these shafts in (IMO) is just asking for trouble. As was mentioned before, setting tension too tight can be the culprit, and NOT using the oem stubby is another reason.
 

FlyingEagle

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Mar 5, 2005
Messages
1,635
Location
THE Ottawa
Quoting Brianawd:
The issue with running the stub shaft and having it fail was because of 2 reasons.
1st timing belt set to tight.
2nd to thin of oil used.running 20w50 helps support the gears.

The idea of the turned down shaft was nice but I have see far to many motors die because of the rear bearing going out.

I have been running the stub shaft in 4g63's now for over 12 years and have never had a pump fail. Set belt tension correctly and use 20w50 oil.

Edit also forgot that extending the oil pick up fixed a lot of the issue with pump problems. Hard launch was causing oil starvation.



Interested on the oil pickup issue, lowering. Any insight as to what is done exactly? Spacer, two gaskets and longer bolts .. measure clearance to pan? What clearance was measured to the pan. Curious, and slightly off topic. PM me if you can.
 
Last edited:

Street Surgeon

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Mar 3, 2004
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941
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Omaha, Nebraska
There's actually a few things that can be done to help out with that. One being to actually extend the tube and put the pickup "saucer" lower, the other being putting a cap over the screen. Kiggly ran a lowered pickup with a modified cover for quite a bit, another trick is to *gasp* add about an extra 1/2qt of oil.

OEM 90-99 oil pickup screen.


S13(and 14) oil pickup screen covers.


Put that over your screen, and be sure to measure your clearance to the bottom of the pan with some modeling clay /ubbthreads/images/graemlins/wink.gif
 
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Kenny_Kline

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Dec 27, 2007
Messages
789
Location
Seekonk, MA
So machine shop just put everything together to check for clearances on standard size bearings and I'm getting .0030-.0032 in main bearing clearance and .0026-.0028 in rod bearing clearance.

So what in going to do is coat the main bearings to tighten it up a little but and then order rod bearings that are .001 extra oil clearance and coat those too. Usually the coating gives about .0005 tighter.

Thoughts? Motor should be done next week ready for pick up
 

prove_it

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Jul 3, 2008
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4,201
Location
Sioux Falls, SD
just slap it together.
 
Last edited:

Kenny_Kline

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Joined
Dec 27, 2007
Messages
789
Location
Seekonk, MA
Got my block back from the machine shop. Blueprint results are the following:

.0032" Main oil bearing clearance
.0036" Rod oil bearing clearance
.0035" thrust play (no oil)
.0045" piston to cylnder wall (not including coating)
.012"-.013" rod side clearance
Torque mains to 60ft lbs
Torque rods to 47ft lbs (checked with stretch gauge)

Crank measured in at
2.2435" main journal
1.771" rod journal
1.128" rod thrust
.004" runout

Block measured in at
3.368" cylinder bore size
2.402" main bore

Rods measured in at
1.890" housing bore size
.8271" pin end size

Pistons measured in at
3.364" w/ sideskirt coating
.8273" pin bore size
.8265" pin size

Also had my rotating assembly balanced which included the crank, flywheel and pressure plate. The crank alone showed 2.61g (left) and 4.12g (right) initial unbalance. Balanced the crank to under a gram then put on the flywheel and it did nothing. Then threw on the pressure plate and it threw it out of balance again so had to drill some metal out of the pressure plate. Final unbalance all said and done was .77g (left) .62g (right)

A couple issues I have are the main bearings are a little to loose at .0030"-.0032" so I am going to send out the bearings to have them coated to tighten it up. It should be .0025"-.0028" after coating.

The rod bearings originally measured in at .0026" clearance so we had to order .001+ extra clearance to give me my .0035" I was looking for. I am going to have these coated also and if the coating makes it to tight, the coating will wear off fast and it should basically ask for its own clearance naturally.

The rings were gapped to big out of the box. Top measured .024, 2nd .032, oil .028. The oil seems fine but I am looking for a .022/.024 1st to 2nd ring gap so I will have to contact wiseco for the correct rings

So so far so good. Any input or concerns appreciated.





 
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