North American Turbocoupe Organization



A little engine advice if you please
Chas K 88 Offline
Member
#1
In the fall as it gets cooler here in IA, when I predict the state is gonna start spraying the bridges & roads with calcium I park our good cars to prevent rust (What, you guys don't?). Well with the bird nestled in her house, I don't see her every day and turn my attention to what I do see, which is my 02 Powerstroked Superduty. I've been hanging around "ford-trucksdotcom" all winter but now with spring around the corner it's time to come back here.

I discovered late last fall a problem with coolant getting into the exhaust. As I was replacing the head gasket and checking the heads flatness I discovered the head had been machined flat by the PO when he rebuilt it. The block on the other hand had not, it wasn't flat either, IIRC the clearance was .006" or more when I measured from corner to corner. I remember hoping it would seal anyway but it didn't so now I need to pull it this spring and have the block machined. One concern I have is the PO put in .030 pistons & I recall reading on here that it is too much in many cases for these engines, should I look for another engine, or spend the $$'s to machine this one? The other concern is with the block & head both machined, will the timing belt be too long?

I cruise with this car 90% of the time (almost a consistent 30 MPG) but I'm not totally against feeling the affect of boost on occasion. It still has the original turbo and I don't plan to do much to it for more power at this time.

What do you guys think?
Chas K
Current setup - 88 T-bird, 5 speed, vacuum assist master cylinder, T3/T4 50 trim turbo from Bo-port, oil feed & return lines, 3” turbo down elbow, 3" to 2.5" dual exhaust and PiMPx from Stinger 255LPH fuel pump, CD, trip-minder, RR , K&N, 140 MPH speedo conversion (thanks Jeff K).
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Sluggo Offline
Posting Freak
#2
My engine is .030 over as well, and I don't worry about beating the snot out of it. The timing belt tensioner will take up any slack in the belt, so that shouldn't concern you either. I beleive it retards the cam timing a very small amount which is also a non-issue.
That's what I think. Smile
Doug  
88 TC / T5,4.56,Log,SC60,NPR,2277,MegaSquirt
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jmthunderbirdturbo Offline
Posting Freak
#3
even if the retard in the timing DOES cause an issue, an adjustable cam gear is a cheap and easy way to cure the problem. and for the 268 comp, a little tuning might not be a bad thing.

.006 doesnt seem like enough to cause the leak though. ive run far worse with good results. are you certain that the leak is coming from that? the cylinder head has been known to leak coolant into the exhaust valve seat, causing the same problem. what HG did you use for the rebuild? the 8993 is not as forgiving as say, the 1035 would be. i run the 1035 with ZERO issues, and will never run another gasket ever. made up for a substantial warp on the front 1/2 of my block (.011 i believe).

id do a compression check, and then when (if) you remove the head, have it checked for cracks and such. its possible that the head is your issue.

these blocks are very stout, and .030 over isnt an issue. .040 requires the block to be checked for clearance, but for the most part, even that is ok. (hard to find pistons though)

-J0N
APRIL 2018 - LOOKING FOR A NEW CAR. PM me if you have an 87-88 roller or cheap TF for sale.
1988 TC 5MT-Blue/Blue check-off car. resto-project.
2006 Honda Odyssey 5AT, baby-mobile.
2013 F-150, 5.0, 6AT, 4x4, snow white paint.
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turbobird63 Offline
Senior Member
#4
I had my motor bored .03 over and I find out later it didnt even need it. Only had 62000 miles on the block. at any rate, I beat the crap out of mine too. No issues what so ever, runs at a consistant temperature and everything is good.

I also run it timed at 12 deg and 20 psi boost day in and day out.
Christopher Taylor
85 TC, 2.3l, LA3, T3/T4 Turbo 25psi, Stinger FMIC, Forge BOV, Full 3" Exhaust, Esslinger crank pulley- Timing Gears and overdrive WP pulley, BBK 255lph FP, Kirban AFPR, Kirban Shifter, K&N Cone, 3g Alternator, Energy Suspension Bushings throughout, CHE LCA's, Welded SFC's, and TON's of other parts.
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Pete D Offline
Administrator
#5
You should do a compression test, maybe a leak down test. It may not be a head gasket problem. 0.006" is the max allowable warpage, overall, that the factory allows.
http://www.merkurencyclopedia.com/Motor/...rhead.html

You might want to read the head gaskets parts of this article. Some feel the 1035 needs real flat surfaces. The Felpro 8993 is cheaper and I have found it durable. On a stock or near stock engine
it should be very good.

I'd run the block you have unless you find a more serious problem with it. Personally, I wouldn't go beyond 0.030" over but others have. Some go 0.030" over to help with unshrouding the valves.
Pete Dunham


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Chas K 88 Offline
Member
#6
When researching specs while doing my head gasket change out I was told 0.003" in any 6" and 0.006" overall was the limit for warp. So being at the upper limit (or maybe over the limit) I was concerned. Also I remember there were none of those hollow dowel pins at the corners even though there were provisions for them. I used the 8993 because the local NAPA didn't have the other, also used new TTY bolts because the ARP rep I talked to said not to use studs unless it is bored & honed with the studs in & torqued. :confused: I didn't understand it then & I still don't.

Sounds like I should remove the head again and have it checked for leaks at the valve seats are the seats changeable? I assume I should remove the cam before taking it to the machine shop so it don't get misplaced Wink If nothing shows up there I'll pull the engine and have it milled. I'll order the FP 1035 and pray constantly as I put it all together. Now where did I read that .030" was too much overbore :confused:
Chas K
Current setup - 88 T-bird, 5 speed, vacuum assist master cylinder, T3/T4 50 trim turbo from Bo-port, oil feed & return lines, 3” turbo down elbow, 3" to 2.5" dual exhaust and PiMPx from Stinger 255LPH fuel pump, CD, trip-minder, RR , K&N, 140 MPH speedo conversion (thanks Jeff K).
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Chas K 88 Offline
Member
#7
Pete you slipped that article in while I was typing.
So I don't need new head bolts again?
Stay with the 8993?
How about the hollow dowel pins?
Thanks again.
Chas K
Current setup - 88 T-bird, 5 speed, vacuum assist master cylinder, T3/T4 50 trim turbo from Bo-port, oil feed & return lines, 3” turbo down elbow, 3" to 2.5" dual exhaust and PiMPx from Stinger 255LPH fuel pump, CD, trip-minder, RR , K&N, 140 MPH speedo conversion (thanks Jeff K).
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Pete D Offline
Administrator
#8
By all means get the dowel pins. Any machine shop should be able to get them. i got some that way and I don't think they cost much.

Quote:Now where did I read that .030" was too much overbore
J.D Laramie (sp?) posted, a few years ago, at TF, about doing some sonic checks on blocks and he concluded that some blocks had thin walls at 0.030" over. Depend on some factors including potential core shift in the mold process. I've mentioned his post here a few times.

I would use the 8993 on a stock or even modified engine. Kind of one of those "what makes you comfortable" things
Pete Dunham


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Sluggo Offline
Posting Freak
#9
What Pete said, get the dowels. I use the 8993 HG and have no problems with it.

Having the head checked out is a good idea while it's off. My car had an oval port on it when I got it and it's sitting in the garage with cracked seats. If my block was right at the limits of warp, I would just put it back together (with dowels and 8993) and run it. If it would make you sleep better, pull it all apart and get it machined.
Doug  
88 TC / T5,4.56,Log,SC60,NPR,2277,MegaSquirt
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Chas K 88 Offline
Member
#10
Quote:Originally posted by Sluggo:
My car had an oval port on it when I got it and it's sitting in the garage with cracked seats.
So,, If I have a coolant leak at the valve seats I have to replace the head?? I don't understand, is this a crack that happens and cant be repaired?
Chas K
Current setup - 88 T-bird, 5 speed, vacuum assist master cylinder, T3/T4 50 trim turbo from Bo-port, oil feed & return lines, 3” turbo down elbow, 3" to 2.5" dual exhaust and PiMPx from Stinger 255LPH fuel pump, CD, trip-minder, RR , K&N, 140 MPH speedo conversion (thanks Jeff K).
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