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Engine rebuild - advice wanted
I was at VIR at SVT Superfest last weekend with the track car (TrackRat) I share with a friend. My first time at VIR and a great weekend.....right up until TrackRat ate it's crank.
The engine was built in 2000 and has probably seen 8,000 track miles since then, so we were thinking we'd rebuild this winter anyway. Guess it will be sooner than that. Sooooo......here is what's in there now. Engine Details RWHP/TQ 360/360 (dynoed recently): From the builder in 2000 (but not verified as we've only owned it for a few years, although we also know the previous owner): Built by Terry Iselin Racing Engines 302 with main girdle Probe Pistons, neg 3cc dome 10.45:1 compression ratio Childs & Albert rings, z depth (zero gap), 3/16 second ring Probe tool steel wrist pins, .125 wall, .927” x 2.500” Eagle 4340 steel crank, 3.400” stroke 2.100” rod journals (Chevy size) ACL bearings Eagle 4340 connecting rods, 5.4” TFS twisted wedge heads, 63cc, flowed 260cfm @.500 lift intake, 167cfm @.500 lift exhaust; 2.02” intake valve, 1.600” exhaust valve Crower valve springs #68390-3 Lunati cam, 224/232 duration, .568/.578 lift, 112 centerline, installed at 108 Edelbrock manifold 70MM throttle body MAF, K&N air filter WMS programmable EFI computer system MSD 6a ignition, Ford Racing high output coil Griffin radiator with integral oil cooler Canton road race oil pan HPM large tube headers with X pipe Criteria: Track only application Want a 302 based block so existing equipment bolts up easily Durable Needs to run on 93 octane At least the same HP/TQ, more is better.... Willing to reuse existing equipment Quality over budget, but still paying attention to the budget (not totally defined yet) Ideas we have been kicking around: -Buy a short block from Ford Racing and reuse existing components -Sell our existing top end and buy/build a complete engine -Carb vs EFT? -Send our top end to a builder and get his evaluation of matching that to a strong bottom end -Buying a racing crate motor -Using a builder for all part of the above (blykins, you paying attention?) - note: this is my preferred course of action, although I have a partner in this track car and it's not 100% my decision..... Anyway, opinions welcome! :cool: |
Did you spin a bearing or did the crank fracture?
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Looking at that list you already have some very good parts there. You could easily reach those goals just by fixing the damaged piece unless something went catastrophic. Might be as simple as a new rotating assembly and a freshen on the rest.
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Aftermarket block
DC If you are going to race full time, the couple of things I would change is aftermarket block and use all the good parts from old motor. Save old motor as spare bullet for during race season. Have all the lastest oiling mods done to the block for faster return to oil pan. If mind, add an oil line to back of motor at the lifter galley. helps supply oil to back crank and rods faster on startup and racing.
Can you go dry sump?? This would be a BIGGIE for longer life of the motor. Not cheap but worth it. If this is not doable add a 3 quart accusump to the oiling system with manual control. rest of parts seam great and all work togeather for that motor combo. When where the valve springs replaced? No valve job but check the valves for sealing on the seats with fluid and a light valve hand grinding to reseal. Intake manifold, if this was not ported send to Joe Craine to have ports balanced for flow, same applies for injectors, clean and have flow checked. New O 2 sensors and way you go. Rick L Ps what main or rod bearing went?? |
Hi Doug...
You and I go back a ways, so give me a call and we'll see what we can do. I would reuse as much as you could, but steer clear of the Eagle junk. A 4340 crank should not break in a 400-425hp engine. Of course there can be other reasons as to why that would happen....bearing failures, balancer failure, etc., but I have 0% confidence in anything with Eagle's name on it. That 347 should make some serious power with a little more cam and a carb setup or a different EFI setup altogether. The Edelbrock EFI intakes are not known for their ability to move air. |
Thanks for the advice guys!
A few responses/comments: -While the car is a dedicated track car, it is used ~10x per year in HPDE events, so not raced hard core, so dry sump is seems like overkill, but accusump seems like a very good idea. -With little kids I don't have a lot of time for major projects, so durability is a big deal and I'd rather spend a bit to upgrade components if necessary. -The crank is definitely broken (crank pulley wobbles when you turn it over along with some unpleasant metallic noises). The engine is still in the car and probably will be for a bit, so I can't attest to contributing factors that led to crank failure. Also don't know what other collateral damage came with the crank failure....yet -Oil pressure didn't drop, but also didn't increase with RPMs as much as I would have liked, so that may have been a contributing factor. -I believe the 302 block is the original that came with the car, so an aftermarket upgrade would probably be a good idea -I thought the older Eagle cranks were better (this was probably a 1999 Eagle crank)? Doesn't really matter since it's broken, just curious. -Maybe want to replace the Eagle connecting rods too. Any other thoughts, I'd love to hear them. :) |
Unfortunately, any Eagle crank, no matter what year is a grenade in my opinion.
You do not need an aftermarket block for your power levels. A block alone would start at around $1700, plus machine work. With your heads, intake, and cam, it's simply not warranted unless the money tree is in bloom. :) |
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Oh, I added it into my original post, but the motor needs to run on 93 octane like it does now.
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Shouldn't be a problem.
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and without knowing what all is damaged,it could be as little as the crankshaft or the whole bottom end........ David |
I'm not trying to start a debate,nor am I looking for one,just stating what's in my 2 cars....
First car is a dedicated road race 65 Mustang,331 cu in.,alum. heads,13.5 to 1 compression, shift at 6500rpms, 7000 chip in the MSD box which I hit on almost every track..just shy of 500hp..I've run oil temps of up to 270 depending on the track and outside air temp......While I "use" the engine for it's intended purpose, I have at times abused it,but not on a regular basis.... With all that said and done, my rotating assy. is/was an Eagle 4340 forged unit...4340 forged crank,chevy journals,4340 forged H-beam 5.4 rods...solid roller camshaft,forged Diamond dome pistons....it ran 7 long hard seasons with only regular oil changes,probably as many miles as you'll put on you'lls car...... It did break, 100% my fault when I screwed up on re-assembly after 7 years.....all it required at the time was a light hone in the cylinders and new rings/bearings, that's it......I replaced the rotating assy. with another, the exact same one I had in there before....... I saved the crank and 6 rods and they were re-used in another 331, street engine making about 425 hp....this is a street car engine (car #2,65 Fastback) that doesn't go past 6000 rpms.........so far,so good...... David |
We typically shift between 5.5-6k RPMs, so I don't think we were over revving it or abusing it more than any engine that spends most of its life above 3k RPMs.....
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If that is all you rev it more camshaft would be of no benefit?
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I've been a bit tentative with this engine as I just didn't trust it. I'd love to have more faith in it and would be happy to push it harder.
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First of all, you need to find out what happened to this engine and why, then go from there.... David |
As we look at options, does anyone have opinons on the new 363 500hp Boss Crate Engine?
363 CUBIC INCH 500 HP BOSS CRATE ENGINE REAR SUMP | Part Details for M-6007-Z363RT* | Ford Racing Performance Parts |
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David |
I think we could certainly get it done less expensively than this by reusing a lot of our existing parts, but this is a relatively quick turnaround option and the 2yr warranty is enticing.
Any known reliability issues for these big bore 302 Boss engines when being used almost exclusively for HPDE events? I assume we could reuse our existing distributor and wires, but I think we will want to upgrade our intake and possibly go to a carb. We will also need a new flywheel as our engine had a non-standard balance. The in-between is obviously a short block. I am also talking to Brent about rebuild options. |
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As is with most engine builders............. David |
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