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Callmewhitexr7
11-22-2004, 12:30 AM
This is going to be the 3rd motor i've had to get put in my sc since august of last year. And I'm getting tired of replacing the motor or fixing it. It has a knock now, not really bad you can't hear it at idle, but at around 1500 to 2500 you can hear it the above 2500 it goes away. when you hold the throttle open to 2500 rpms and remove the plug wire from cylinder 5 it doesnt go away but it does quite down alot. so my ? is what should i do.

tim
11-22-2004, 10:12 PM
For the price of three engines for could have put a 460 in it.

MikeKanterakis
11-23-2004, 10:25 PM
Do it once.

Do it right.

Rebuild it completely, and get another 100,000+ miles out of it.

Today's cool cars are tomorow's classics. Keep it on the road! ;)

cowtown
11-24-2004, 02:09 PM
Just to clarify as I said get a new motor... You have put in 3 motors now? Were they used ones you swapped in? If so did you bother to have them rebuilt? If not, what were you thinking? After dropping engine #2 that would have been my first action.

Callmewhitexr7
11-25-2004, 12:00 AM
Last year in august i bought an 89 xr7 with a spun bearing, had a shop rebuild the motor. Then i wrecked the cougar and swapped the motor into a 89 sc that i bought to replace the cougar. The motor only lasted 8000 miles before breaking the crank in half. So i rebuilt the motor myself and put it back in my sc. It now has over 18000 miles on it and now has a knock. The knock has been there since i rebuilt the motor just not as noticable as it is now and its getting worse. So i said this will be my 3rd motor.


NICK

XR7 Dave
11-25-2004, 11:23 PM
All too often people throw good money after bad and it ends up being very discouraging not to mention expensive. For example, rod bearings don't just "go". There is a cause for the problem. Find the problem and fix it. Under normal circumstances these motors run 200K miles regularly. You can't even say that about a 460. Spending a bunch of money to rebuild the motor in the hopes that you fix the problem is like hunting gophers with a shotgun. Generally effective but wasteful.

Once you have a car that is 15 years old you have to make some allowances for problems. Getting a newer car will generally fix that problem. However, rebuilding the motor is no guarantee that you fixed the problem. Such is life with a 15yr old car.

turbospeed
11-26-2004, 07:02 PM
All too often people throw good money after bad and it ends up being very discouraging not to mention expensive. For example, rod bearings don't just "go". There is a cause for the problem. Find the problem and fix it. Under normal circumstances these motors run 200K miles regularly. You can't even say that about a 460. Spending a bunch of money to rebuild the motor in the hopes that you fix the problem is like hunting gophers with a shotgun. Generally effective but wasteful.

Once you have a car that is 15 years old you have to make some allowances for problems. Getting a newer car will generally fix that problem. However, rebuilding the motor is no guarantee that you fixed the problem. Such is life with a 15yr old car.
dave you just scared me , today my hg's bllew and i was already getting ready for the rebuild , what extra steps could i take to make sure everything is ok?

90SC BIG BLOCK
11-26-2004, 11:57 PM
The other guys are spot on ,BUT you had better find a ford guy with a machine shop because most GM guys who work on or drive them are retardes and they will drive a ford 20 years,dog it ,use it up ,but will baby a smoking GM piece of waste .Take the engine out now and find some body ..NOW

tim
11-27-2004, 12:09 AM
I dont know about you guys but finding a good ford v6 machine shop is almost impossible. Any suggestions for when i build my next engine?

WhiteSC90
11-27-2004, 12:17 AM
My SC has 216,000 on it and i dont know if the head gaskets have even been changed!!!!! You're just having bad luck. Find another low mileage motor or have someone rebuit it that you really trust. Find a buddy that works at Autozone and get the 20% discount on a reman motor. :D

joshbea6
11-27-2004, 08:51 PM
My SC has 169K on it. I pulled the engine. I am doing the following things to ensure that I get at least that much more out of it.

1. Block cleaned and magnafluxed (crack checking)
2. Completely forged internals (stock crank, and rods) Wiseco Pistons .020 over
3. Complete rebuild of the heads (cleaned and magnafluxed)
4. New Cam, not sure yet of specs, got some talking to do with the shop
5. Roller lifters
6. Double Roller Timing Chain
7. High Performance Oil Pump
8. ARP Bolts for everything I can find on the engine
9. Magnum Powers SC rebuild
10. Magnum Powers Power bolt-ons

Basically I am doing this RIGHT the FIRST time so that there is NO second, or third. :D

XR7 Dave
11-28-2004, 09:30 PM
dave you just scared me , today my hg's bllew and i was already getting ready for the rebuild , what extra steps could i take to make sure everything is ok?

Make sure your timing cover is in good shape and get a new high volume oil pump. Get a new balancer, and upgrade the cam, you'll be happy you did. If you have the extra cash, put ARP studs throughout the motor and get it align honed and balanced. I've seen a lot of crooked main caps on these motors. You can keep adding all you want but those are the basics.

XR7 Dave
11-28-2004, 09:31 PM
My SC has 216,000 on it and i dont know if the head gaskets have even been changed!!!!! You're just having bad luck. Find another low mileage motor or have someone rebuit it that you really trust. Find a buddy that works at Autozone and get the 20% discount on a reman motor. :D If you could use your X-ray vision and see what your headgaskets look like right now you'd be worried. All SC headgaskets are shot, just some haven't started leaking yet. It doesn't take much to push them over the edge.

tim
11-28-2004, 11:36 PM
I dont get it. If you are going to go thru all that trouble to get studs, machine work,ect. Spend the money and get a guridle and have the block or heads o-ringed. Why to 3/4 of the job.

XR7 Dave
11-29-2004, 10:30 AM
I dont get it. If you are going to go thru all that trouble to get studs, machine work,ect. Spend the money and get a guridle and have the block or heads o-ringed. Why to 3/4 of the job. As I stated above, "If you have the extra cash" and "you can keep adding all you want but those are the basics." IMO it is smart use of money to match components with your target power levels and not overbuild things. No one has yet proven that any of those things (and even ARP studs) are necessary at any particular power level. I've seen more "bullet-proof" builds fail under power than I've seen stock shortblocks fail so I refuse to endorse the necessity of spending big bucks on the shortblock. My comments about the line hone/bore are based directly in the evidence I have seen from the bearings I have pulled from totally stock motors with high mileage. What I should have added to my list of things to do is re-deck the block because the factory deck surface is extremely rough.

This does not mean that I do not see value in aftermarket rotating assemblies or other things to reinforce the motor. However I do firmly believe that if there is a budget being followed, then the money will be better spent elsewhere.

Callmewhitexr7
11-30-2004, 12:21 AM
Hey dave why did you say make sure the timing cover is in good shape?

SpeeDemonSC
11-30-2004, 08:48 AM
my sc just rolled over 203k, and the crank split clean in 1/2. and i havnet started reassembling the new motor i pulled with 60k on it. is there any building tips any one can give me!( new sc owner, dont know much) any and all help will be greatly appreciated!

MikeKanterakis
11-30-2004, 01:13 PM
Tap every hole on the block and heads when you get them back from the machine shop!!!!

That sand will grab hold of a bolt and NOT let it go. Luckily for me I found that out on a header bolt and still had a 1/4 of an inch of stud left sticking out of the head. Thank God for vise grips.

Rule of Thumb. On a rebuild, all bolts should practically bottom out by hand. If there getting tight before the bolt is 8/9ths of the way in, back it out and tap, tap, tap that hole.

Anti-Seize is your friend.

XR7 Dave
11-30-2004, 09:12 PM
Hey dave why did you say make sure the timing cover is in good shape? On our motors the oil pump gears seal right against the timing cover. If the gears have worn into the timing cover or if dirt has left grooves in the cover, then it needs to be replaced or you may get the motor all back together and find you have lousy oil pressure.

Callmewhitexr7
12-02-2004, 10:13 PM
ah i see so i guess i should get a new cover. Were can i pick one up at?


NICK

90SC BIG BLOCK
12-03-2004, 10:59 PM
[QUOTE=SpeeDemonSC]my sc just rolled over 203k,
Dont go crazy and power mad like me ,but do rebuild the motor. Give it at the minimum a line hone ,do the crank, do the heads, ARP studs, zero gap rings, change the O2 sensors. And if you want 13 sec. , overdrive pully , 4.10-1 ring & pinion , rebuild the limited slip, big fuel pump an regulator,drag radials (255-50-16),shift kit(shift hard like a FORD should).