I need some input on a 390 FE I found
I looked at a 390 short block last night that needs rebuilt. It looks like it is standard bore and in good shape considering it has been sitting in a corner of a garage for many years.
The gentleman also has a 390 fe block .30 over that is apart with a regular crank, forged pistons, forged rods, all bearings, and rings all new still in the box. He says the block and parts have been balanced and blueprinted just never put together. He had some documentation to back it up as well as marks/writting on the pistons and rods so I believe him. My question is would you buy the old block and do it from scratch or buy the one with the machine work already done just taking a chance that it was done right? The difference in price is about $700. This is a project for my sons and I, so any input is appreciated. |
Does not matter
PJ4myboo PJ witch ever block you end up with you are going to send it to YOUR machinist for his testing and check out. Agree on a machinist in your area, pay half now and the other half on completion of testing. The means checking for crack in the bottom end and sonic check the walls. Pressure test the block with a min of 100 psi of water in the water jackets for a possible weak thin wall. After HE gives the OK, then you have a motor block to build. What ever block you end up with, new cam bearings, honing, boring, machine work to have flat surfaces,(Fly cutting) will all need to be done. What heads and intake are you looking at? They also my need to be machined if .010-.20" is removed to get flat surfaces of the block. If the walls are thick, boring it out .060" over will give you some more bore for a set of larger valves in the heads. A 2.19 intake can breath well and better that a 2.09. I may sound like a bad guy but have seen enough people get the shaft buying old parts and motors and NOT having them checked out by there own machinist.%/:CRY: If the guy is honest he should have no problem with this deal, if not you may want to walk away.%/ If the was my motor, I would buy the block and get a stroker kit from Barry R. Go to a 4.25 crank kit. The BBC rods are better than FE rods IMO. BBC rods have a wider bearing and handle the load better. Look at Car Craft in August 2008 for the 446 build up. You follow this and have a very nice motor for a cobra than will last for many years of fun and abuse. Rick L. Ps Barry R. and Keith Craft both sell nice packages for the top end of FE motors. Heads,camshafts, intakes, and carbs. The important thing is having all the paerts work togeather and make the most torque and HP and be durable.%/:):D
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Everything Rick said was right on the money. We've seen guys get in trouble with blocks they didn't have checked out -- and mind you this is a 390FE, so they're everywhere (pretty much). If the owner is hesitant to let you have it checked, walk from the deal.
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Point well taken...I will definately have it tested. Would you go with the old one then?
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I know i'm probably going to get the finger on this BUT if it were up to me i would take the old funky short block and have it done as a basically stock rebuild with cast pistons new bearings throughout and save a ton of money to spend on other things.The only thing i can say is keep it simple,and a basicaly stock engine will run for a long time and give good performance if done properly you dont need BBC rods or 427/428 cranks or trick heads and all that raceing stuff to have a good running engine........
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What do you really want to do?
I mean other than have Keith give you a finished engine for free. DO you want to build it up yourself or are you looking to just assemble what the guy has or is the ready-to-run engine really what you want. This club is large and knowledgable, you will have no problems getting advice...as you can see. I am getting the idea that you are uncomfortable with doing the build yourself, yet in your other thread ( much like this one ) you hinted you wanted this to be a learning experience. But don't rob yourself of that dream of building it all by yourself if that is really what you want to do. Just my opinion. :D |
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Oh we are going to build it.....I'll lock up the video games until they are done!!!!
I'm not uncomfortable building an engine. I have built a few stock engines when I was restoring old Cadillacs years ago. I'm not so sure about a big block Ford, but I'm sure I can figure it out. I think I would be somehow cheating if I bought a finished engine, but that's just me. The way I'm looking at it, we are assembling either way. One already has the parts and one doesn't. I am leaning toward the funky block, though. I can let the boys get dirty tearing it down. Actually, a stock build/rebuild might be a good thing for our first build. Thank you so much for all of the input. I truly appreciate it! Pete |
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I'm still wondering what happened to the t-bird engine, if it was still a complete engine you would have all the parts you would need to do a rebuild, block crank,rods,heads and all the nuts and bolts and other assorted parts to start a rebuild and if it is the right year t-bird it would have a c6 trans you could use also.........that would take care of 2 big pieces of the running gear.
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Just throwing in my two cents worth here but I agree with building a rather stock FE power plant for a street driven Cobra for many reasons, mainly cost savings and reliability. I don't mean to step on toes, but over the years I have read so many posts from guys who spent a whole lot of money building a high powered exotic power plant for their cars and ending up having trouble with breakage, leaks, difficulty tuning, not running up to par and other assorted problems. The wild motors are fun to listen to but not so much fun when they break.
A street driven Cobra roadster is a light car and with even a stock 390FE in well thought out stock bottom end trim will have more than enough power and torque to satisfy most drivers. I would, of course, lighten things up with aluminum heads and intake but would top it off with two Holley #8007 390 cfm carbs after tweaking the jets a little just for the WOW appeal. For street performance they will give more than enough breathing room for a stock motor. I admit I am partial to a manual gearbox in a Cobra but would try and opt for a super duty close ratio T-5 rather than a top loader because of the nice 5th gear for cruising (1750 RPM at 65 mph with a 3.50 rear). A setup like that should give plenty of enjoyment without causing another recession. If this was my choice, I would opt for the stock rebuildable short block and have my own machinist go over it thoroughly and have him make recommendations about machine work and build-up parts stressing reliability rather than exotica. |
First motor in my Cobra
PJ4myboo Pete I started with the thought of a street car driver until I found out what a pain in the BUTT the NJ CAR Division is to get through. I added FI system to the car and needed more safety things added for street driving. My fuel lines are Aluminum and this is not allowed.
Anyway My motor is a 428 iron that turned into being a 410. The guy lied to me. 390 motor with a 428 crank. This motor runs good for all stock. The cam shaft was changed to a 501-533 small crane hydro lifters. It made 280rwhp and 354 ft of tork. smooth idle and run low 13.0's at the track. I did abuse this motor some. Limit the rpms to 6,000. Everything was stock but carb, intake, dual plane Edelbrock, and cam shaft. At the end of the season I was having oil pressure problems, 10 psi at idle hot and 40-45 psi at 2,500 rpms. Bottom end bearings where going. Motor is in shed Got a new Shelby block when they came out CSX 58# I used a cast 428 crank, eagle rods and diamond pistons. 7 1/2 quart oil pan. I talked to some of the old machinist from the 60's and ALL said that with FE rods you need to run a high oil pressure from the rods being heavy and bearing width being smaller than other Big Block motors. This explains why we are running BBC rods in stroker motors and having less to no failures. The rods have a wider bearing for load and better oiling to the rod bearings and mains. I ran my 452 motor for 8 years of track only racing and had 2 failures of rockershafts. I do run a HVHP oil pump with 100* spring. You don't need this for a street motor but IMO an 80* spring should be used with FE rods. ARP bolts are needed for the rods, mains and head bolts. You have to remember that. There is more but have to go to work, finish later. Rick L. One note a motor will die fast from not enough oil, too much oil pressure is another question. In my case same block of racing for 8 years and no bottom failures. I am now running a 482 stroker kit going on 3 years. no problem with bearings or bottom end. The reading you see at the gauge is NOT the reading the last main and rod bearings are getting,#4 & #8. They also get oil last unless you have a sideoiler motor. 10-30 psi drop from front to back of motor. I do have a accusump as a pre oiler before startting my motor. It gives 35 psi before firing up. No dry starts.%/;):) |
I'd get the one that's apart. Build it yourself and you know what you've got. I agree with using ARP rod bolts, but crank and head ARP bolts is a bit of overkill unless you are trying to make serious horsepower and racing Lemans. I would suggest new flywheel bolts, still available from Ford.
I tend to think that the oil requirements at the bearing are the same for any make of engine. The FE has narrow oil passages, so to obtain the oil flow you need at the bearings, you need more pressure back at the fliter where the oil guage is tapped from compared to say, a Chev. The oiling mods are easy as cast iron is soft to work with. I tried a HVHP pump once. Not good. Pressure pegged my guage. Puts a lot of stress on the dist, dist gear, oil pump driveshaft, etc. In fact, even with oil pressure in the 80s (HV pump only), some distributors can shear the gear roll pin. I had to double pin (nested) my Mallory for that reason. Anyway, that HPHV pump would also pump the oil pan almost dry when the oil was cold....took too long for the oil to drain back from the heads compared to what the pump was pushing through it. (And "yes", I did have restrictors in the heads.) How I tell? Once the car was started, I'd attempt to back out of the garage and the slight sloshing of the little oil remaining in the pan would allow air into the pick-up and my guage would bounce around. Although expensive, I wound up using an Aviad oil pan. I called them and they added a rear bung for the oil temp sensor for free. 9 qts in the pan plus what's needed for the filter. I also made my "blue-printed" HVHP oil pump adjustable and set the oil pressure for about 85 psi prior to installation. A strong recommendation is a heavy duty oil pump drive. I wouldn't build an FE, even stock, without one. And buy a new balancer....I have just spent a ton of money re-building my engine because I set the timing to the marks on a balancer that was slipping and got massive detonation resulting in a broken piston. Back to your prospective purchase. It would be nice to be able to presssure check, sonic check, etc. a block you are thinking of purcdhaasing, but the reality is most owners down't want you leaving with the block and possibly bringing it back damaged, or not returing to pay for it. I just take my chances on the purchase and have it checked after the deal by the machine shop for cracks, etc. If it's bad, an honest Seller may give you your money back. I do my own pressure test, but only at about 30 psi, double that of normal water pressure. Just leave it hooked up for a while, if there's a crack, the water will eventually seep out...er....most of the time. I may do the 100 psi check mentioned earlier next time as I once did split a block.....water jacket inside valley area cracked and split open. Guess I put more stress on the engine than it ever got in the old family wagon. Mind you, I had a few thousand miles on the engine before that happened. Pre-oiling the engine prior to start up. Great idea. Happens automatically for me. I dont' use a choke, and crank it a bit before I pump the gas pedal to start it. I suspect the best thing is to switch from mineral oil to synthetic once break-in is complete. According to Smokey Yunick, synthetic has saved some of his engines even when an air bubble has been sucked up by the oil pump due to hard cornering, accelration, or whatever. Only bad thing about it that even the smallest of leaks, synthetic will find its way out quite easily. Holy crap, I'm writing a novel...and a very opionated one too.....sorry about that. Good luck with your decision. |
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pj4.......I dont want to sound like a broken record but i'm a firm believer in keeping things simple....get as many parts as you can at one time,motor/trans and as complete as you can,carb to oil pan, altinator to trans yoke this saves time and money running around looking for that 2 dollar item that seems to hold things up at the last minute.
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Well, I took your advice and told the guy I'd pay half now and half after testing for the old block and he refused. Needless to say, I walked away. I saw a complete engine out of a '67 Fairlane advertised today that I'm going to look at this week. It supposedly runs, so we will see.
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If I may ask, what are these engines going for?
:D |
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