First time engine rebuild
09-04-2011, 11:08 PM
#1
2nd Gear Member
Thread Starter
Join Date: May 2007
Location: Courtenay B.C
Posts: 405
First time engine rebuild
My mustangs engine is getting tired and over the fall and winter coming up I would like to rebuild it. I have a little bit of mechanical background but not much. I have a lot of questions and am hoping I could get some answers and opinions.
First off what exactly should I replace, my engine has 125000 miles on it, its burning oil and leaking a little bit of oil. I am on a tight budget and am buying a set of gt40p heads that have 95xxx miles on them and are in good condition. I was thinking just a hone job and new rings but if I am already that far what else should I get done at machine shop? What about timing chain, lifters ect
Second I want a mild h/c/i but wont be able to afford it all at once, Would I be able to run gt40p heads and say a tfs 1 cam with stock intake, tb, injectors, maf until I can afford to replace all that?
Third what kind of tools will I need besides basic wrenches, sockets ect. Also what about books or manuals? I have a Haynes already btw.
I am probably forgetting a lot lol....
First off what exactly should I replace, my engine has 125000 miles on it, its burning oil and leaking a little bit of oil. I am on a tight budget and am buying a set of gt40p heads that have 95xxx miles on them and are in good condition. I was thinking just a hone job and new rings but if I am already that far what else should I get done at machine shop? What about timing chain, lifters ect
Second I want a mild h/c/i but wont be able to afford it all at once, Would I be able to run gt40p heads and say a tfs 1 cam with stock intake, tb, injectors, maf until I can afford to replace all that?
Third what kind of tools will I need besides basic wrenches, sockets ect. Also what about books or manuals? I have a Haynes already btw.
I am probably forgetting a lot lol....
Last edited by 5.0stang123; 09-04-2011 at 11:11 PM.
09-05-2011, 05:50 AM
#2
2nd Gear Member
Join Date: Jun 2011
Location: Ohio
Posts: 166
Congrats! Engine building is fun & rewarding IMO.
If your only talking about increasing power by about 100hp at the most, there is not an awful lot you have to do differently other than a basic rebuild with a few additional things.
As for the bottom end, a stock overhaul kit would be fine. IMO I'd:
1 - Disassemble using many digital pictures of the engine compartment and engine during removal. Number each part for which cylider they came out of. Also, mark them so that you know what the orientation of each part is.
It shouldn't matter for the rods and piston pins... but its always nice to know EXACTLY which part came from where and how it was orientated. That way you can always "go back to square one".
2 - Increase the main and rod bearing gaps by about 15%-20% over stock and use a higher volume oil pump. (example a 0.0010 clearance * 1.15 & 1.20= 0.00115 & 0.0012 respectfully) Seems like a small amount, but this will help thermal expansion for parts seeing a higher than normal load & that may not be as square as new parts would be. It'll also help the bearings live longer at high rpms. (assuming a high volume oil pump)
3 - Use ARP studs with the special assembly lube on the threads. TQ the studs in 10lb incriments using the torque sequence in the ford manual. Then over the next 3-4 days re-torque up to spec. By the 4th day they should all be holding at max tq. If not you very well might have a bad stud. (this happens more than people know)
4 - Buy a digital scale that goes down to 0.1g and static balance the parts to match the lightest rod / pin / piston combo. Pay the most attention to the big end of the rod as this is what causes the most imbalance. This greatly helps bearing life for higher rpm use, helps guard against breaking parts, and reduces friction which = more power.
5 - Wash the bores with dish soap and something that won't leave debris. Wash them until you get no more discoloration coming off on a white cloth. Then spray them down with brake cleaner to completely ensure no lint or other chemicals are present. Then oil (or not) based on what the ring supplier suggests.
6 - Talk to the ring supplier about what end gaps, bore roughness, and oil to use to help ring seating. On my last engine I used chrome plated rings and no oil in the bores. Spun the short block over about 100 times by hand.
NOTE: Don't try to 2nd guess what the ring supplier says to do. Tell them exactly what you want to protect for (nitrous, SC, turbo, NA) and then set end gaps exactly as they say. The bigger the gap the more oil you'll use & the more blowby you'll have. Its all a trade off in what it is you want to achieve. As a point of reference.. my last engine was 800hp on SC & nitrous. I had HUGE end gaps at 0.025" top 0.021" middle. Oil consumption was about 1qt every 1000 miles after everything was seated (after 3000 miles)
7 - Check the oil pan to oil pump puck distance. Don't assume its ok! A mound of clay or playdoe is an excellet way. Too close and you'll starve the bearings at high rpms. Too far... is not really an issue. My rule of thumb is to use the factory spec as a minimum / target. Might want to measure the stock setup during dis-assembly.
8 - use acetone or brake cleaner to clean the sealing surfaces. A thin coating of rtv is all it takes for gaskets. And if you have a joint that is rtv only.. spread it to cover 100% of the surface on both parts. When you screw the parts together just snug them and then 1/2hr later tq them to spec.
9 - As your torquing down the crank check the resistance of spining the crank. Ideally you want to see a 5ft lb effort to get the crank to move. IMO anything over 12-ish ft lbs is too much.
10 - If you feel lucky.. chamfer the cranks oil holes. Be careful not to slip and put a mark in the cranks journals. Personally I chamfer them and then round the corners. But you gotta be ultra careful to not slip.
If you clean your stock pistons and hone the cylinder bores you'll likely have a little piston slap when the engine is cold. IMO this is not a big deal and nothing to be concerned about. Just be aware of what that noise is.
When cleaning the pistons don't use any abrasives that would remove metal. I've heard that people soak them in tranny fluid. I've done that but only let them sit in it for a few hours which didn't help much. You might try doing it longer or using a professional fluid that is made for this. Tricky part is getting the ring grooves clean w/o material removal. It is possible, just tedious. You could easily spend 2 hrs on each piston if you can't find a way of disolving the carbon. First time I did this I used a pocket knife and my finger nails. It took a long time but worked just fine. On that engine I had a little piston slap w/5w-30. Switched to 10w-30 and it only made a little noise for the first minute during warm up.
The three things I focus on for a "tight budget" are; cleanliness, balancing, and rotational friction. If spending money.. making parts square / round with torque plates and rotationally balancing is well worth the added cost. But cost they do!
There are more things.. like cleaning the block, new timing chain, new lifters, new cam bearings, crank end play, ect.. just read all you can, clean parts well, check and re-check TQ, check rotational effort, and have fun.
If your only talking about increasing power by about 100hp at the most, there is not an awful lot you have to do differently other than a basic rebuild with a few additional things.
As for the bottom end, a stock overhaul kit would be fine. IMO I'd:
1 - Disassemble using many digital pictures of the engine compartment and engine during removal. Number each part for which cylider they came out of. Also, mark them so that you know what the orientation of each part is.
It shouldn't matter for the rods and piston pins... but its always nice to know EXACTLY which part came from where and how it was orientated. That way you can always "go back to square one".
2 - Increase the main and rod bearing gaps by about 15%-20% over stock and use a higher volume oil pump. (example a 0.0010 clearance * 1.15 & 1.20= 0.00115 & 0.0012 respectfully) Seems like a small amount, but this will help thermal expansion for parts seeing a higher than normal load & that may not be as square as new parts would be. It'll also help the bearings live longer at high rpms. (assuming a high volume oil pump)
3 - Use ARP studs with the special assembly lube on the threads. TQ the studs in 10lb incriments using the torque sequence in the ford manual. Then over the next 3-4 days re-torque up to spec. By the 4th day they should all be holding at max tq. If not you very well might have a bad stud. (this happens more than people know)
4 - Buy a digital scale that goes down to 0.1g and static balance the parts to match the lightest rod / pin / piston combo. Pay the most attention to the big end of the rod as this is what causes the most imbalance. This greatly helps bearing life for higher rpm use, helps guard against breaking parts, and reduces friction which = more power.
5 - Wash the bores with dish soap and something that won't leave debris. Wash them until you get no more discoloration coming off on a white cloth. Then spray them down with brake cleaner to completely ensure no lint or other chemicals are present. Then oil (or not) based on what the ring supplier suggests.
6 - Talk to the ring supplier about what end gaps, bore roughness, and oil to use to help ring seating. On my last engine I used chrome plated rings and no oil in the bores. Spun the short block over about 100 times by hand.
NOTE: Don't try to 2nd guess what the ring supplier says to do. Tell them exactly what you want to protect for (nitrous, SC, turbo, NA) and then set end gaps exactly as they say. The bigger the gap the more oil you'll use & the more blowby you'll have. Its all a trade off in what it is you want to achieve. As a point of reference.. my last engine was 800hp on SC & nitrous. I had HUGE end gaps at 0.025" top 0.021" middle. Oil consumption was about 1qt every 1000 miles after everything was seated (after 3000 miles)
7 - Check the oil pan to oil pump puck distance. Don't assume its ok! A mound of clay or playdoe is an excellet way. Too close and you'll starve the bearings at high rpms. Too far... is not really an issue. My rule of thumb is to use the factory spec as a minimum / target. Might want to measure the stock setup during dis-assembly.
8 - use acetone or brake cleaner to clean the sealing surfaces. A thin coating of rtv is all it takes for gaskets. And if you have a joint that is rtv only.. spread it to cover 100% of the surface on both parts. When you screw the parts together just snug them and then 1/2hr later tq them to spec.
9 - As your torquing down the crank check the resistance of spining the crank. Ideally you want to see a 5ft lb effort to get the crank to move. IMO anything over 12-ish ft lbs is too much.
10 - If you feel lucky.. chamfer the cranks oil holes. Be careful not to slip and put a mark in the cranks journals. Personally I chamfer them and then round the corners. But you gotta be ultra careful to not slip.
If you clean your stock pistons and hone the cylinder bores you'll likely have a little piston slap when the engine is cold. IMO this is not a big deal and nothing to be concerned about. Just be aware of what that noise is.
When cleaning the pistons don't use any abrasives that would remove metal. I've heard that people soak them in tranny fluid. I've done that but only let them sit in it for a few hours which didn't help much. You might try doing it longer or using a professional fluid that is made for this. Tricky part is getting the ring grooves clean w/o material removal. It is possible, just tedious. You could easily spend 2 hrs on each piston if you can't find a way of disolving the carbon. First time I did this I used a pocket knife and my finger nails. It took a long time but worked just fine. On that engine I had a little piston slap w/5w-30. Switched to 10w-30 and it only made a little noise for the first minute during warm up.
The three things I focus on for a "tight budget" are; cleanliness, balancing, and rotational friction. If spending money.. making parts square / round with torque plates and rotationally balancing is well worth the added cost. But cost they do!
There are more things.. like cleaning the block, new timing chain, new lifters, new cam bearings, crank end play, ect.. just read all you can, clean parts well, check and re-check TQ, check rotational effort, and have fun.
Last edited by wydopnthrtl; 09-05-2011 at 06:29 AM.
09-05-2011, 07:29 PM
#3
4th Gear Member
Join Date: Apr 2009
Location: N.C.
Posts: 1,893
Blew up my first motor and went to library for information. Was in 1969, now should be no problems with proper information. Read and get familiar with subject, few digital pictures, and with magic marker and baggies should be fun.
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