| Author | Message | ||
| Johnny (63.159.196.104)
Rating: N/A |
The 370 is out of my skoolie. The post-mortem wasn't pretty: 4 flat cam lobes 9 concave lifters 1 bent pushrod Enough slack to pull the timing chain off without removing the gears 1 cracked piston Oil rings locked in grooves, several broken All bearings worn down to copper 1 burned exhaust valve All valve guides toast I'm a little surprised it even ran! Currently, the bonnet is off, engine out, & we're attacking 18 years of road grunge with Simple Green. The next step is Castrol Super Clean engine degreaser--this thing is FILTHY. Also, the clutch will be replaced while the engine is out--judging by the disc, someone rode the clutch while it was in service. The 460 has a resurfaced flywheel ($15 at a junkyard, plus $10 to resurface it--I love junkyards), so the 370's flywheel (balanced differently, anyway) isn't needed. Surprisingly, the clutch seems to be original (a Ford part, & the trans appears to have never been out). Rebuilt 460 is ready to go in--just waiting on digging up a timing cover (stocker was bent). Here's the specs: Steel crank, 4-bolt-main block from 1981 F-350 chassis-cab 8.25:1 compression Comp Cams Xtreme Energy cam, hydraulic flat-tappet, 195/210 duration @ .050" lift, 4 degrees advanced Ported 1981 460 heads, stainless intake valves, sodium-filled (ouch!) exhaust valves Cam geardrive Edelbrock Performer intake with 3" plastic spacer (actually, 2 1.5" spacers) 450cfm Holley Economaster carb (free, & worth a shot) Hi-volume oil pump 8 quart oil pan Remote dual filter setup, 2 GM MDT filters (1.5 quarts each) Crank scraper (homemade) Huge oil cooler from a dump truck 1972 460 police car water pump (a third the price of the truck pump--and the same part) Huge flex fan (like, 20" 9 blade) 1975 Marquis cast-iron manifolds Estimates: 275-300HP at 3800RPM (a revver it definitely is not) 500-525lb/ft at 2200RPM | ||
| jmaxwell (66.42.92.17) Rating: N/A |
I liked the part about the Economaster Carb---now that's an oxymoron considering it's on a 460! A good strong engine though. I have one in my '73 Connie that I rebuilt many years ago when it had 135k mi. on it. Did it because of a burned valve. No measurable wear except for .001 taper on the rear two cylinders. But it do eat the gas, and that's in a car (lead sled that it is)! | ||
| RJ Long (Rjlong) (24.127.74.29)
Rating: N/A |
I haven't crunched the numbers yet, but I think you're going to find that the 450 cfm Holley carb is too small for that motor. With all the work that's been put into this engine, I'd hate to see you destroy it by undercarburetting it. . . RJ PD4106-2784 Fresno CA | ||
| FAST FRED (65.58.226.235) Rating: N/A |
IF you live in a cold place you might consider a remote oil filter that has a thermostat so it can controll the temp of the oil sent to the huge oil cooler. Warmup should always be done as quickly as possable. FAST FRED | ||
| DaveD (216.18.113.69)
Rating: N/A |
A quick rule of thumb for carb cfm is to double the engine displacement and pick a carb close to that (e.g. 460 x 2 = 920). An 850 cfm carb should be a suitable for a 460. A 450 cfm carb probably won't hurt the engine, but with that limited airflow, it will never develop adequate power. However there is no advantage to having too large a carb either, e.g. an 850 cfm carb on a 340 cid engine won't make it perfrom better and can create problems. A 650 cfm carb on a 340 is a good match. Dave D | ||
| Ross Carlisle (Ross) (207.88.98.12)
Rating: N/A |
The only 460 I ever had was in a Cobra kit car. It was mildly hopped up and I ran 2 500cfm AFB Carters on it...And it ran great...For a Ford  Most of my experience is in big block Chevy's. A mild 454 won't run well on much less than 800cfm. Ross | ||
| Peter (Sdibaja) (209.242.148.130)
Rating: N/A |
Johnny said: "450cfm Holley Economaster carb (free, & worth a shot)" I have had meny over carbed engines, a small carb will give lots of snap and response, but a possible lack of peak power at WOT and high RPM... It may work out great, Johnny please report, specially if you try a bigger carb to see the difference. | ||
| Bradd B. Smith (Bbsrtbusproject) (208.26.165.172)
Rating: N/A |
I can't wait to hear the next installment in this story. Sounds like you did a great job on the engine. The moves the bus report will be good. Thanks for the up-date, and keep us posted. Let us know top end, take off and mpg. Is this a great hobby or what? | ||
| dougthebonifiedbusnut (24.218.119.24)
Rating: N/A |
hey johnny give us some pics want to see your old girl | ||
| Johnny (63.159.126.161)
Rating: N/A |
This is the formula I've always used for carb size: C x R ----- 3456 C=engine displacement in cubic inches R=max RPM In this case, C=460, and R=4000. The formula gives me 532cfm. Now, this is at 100% volumetric efficiency--which I'm nowhere near. Figuring 80-85% VE, I need 425-450cfm. Thus, a 450cfm carb should be fine on this low-revver. In fact, the 429 Lima engines had (factory) 2bbl carbs, which were in the 300-350cfm range. I need as much low-end power as possible for my heavy (25,500lbs GVWR, & will probably run 24-25K converted, plus a toad), highway-geared (2500RPM is 61MPH, engine drops to 14-1500 on upshifts) bus. If the Holley doesn't work out, it's getting a 600cfm Q-jet from a 305-powered something. Weirdness factor: Chrysler put 800cfm carbs on <200HP 318's FROM THE FACTORY! Next installment? Well, being unemployed again (long story), I plan to finish the cleanup this weekend, barring a job interview (hoping for one tomorrow). I have no pics available, & no way to post them. | ||
| Henry R. Bergman, Jr. (Henryofcj) (63.224.197.10)
Rating: N/A |
Sounds like Johnny did his homework and knows big block Fords. The key here is the application. No way his new 460 is going to see the 5000 to 6000 rpm such as a street mill would. His is a very low rpm application where maximum torque is the overriding factor. Sounds like his carb choice is nearly ideal. I even bet when it gets broken in, his bus will see 7 to 8 mpg! Enjoy. | ||
| Peter Broadribb (Madbrit) (216.67.221.200)
Rating: N/A |
I have one of those school bus Holleys on a shelf in my garage if you need any info or details off it. Peter. | ||
| Johnny (63.159.129.47)
Rating: N/A |
8MPG? That would be nice. The 370 got a steady 3-4. Gotta love no compression left! School bus Holley? Huh? The contraption I took off (I don't want to call this weird-looking thing a "carbuerator") was a 2bbl., with the damn kick-the-pedal-back-into-your-foot governor. No, thanks! I'd certainly appreciate some info, though--but I thought Fords used Motorcraft carbs. | ||
| Peter Broadribb (Madbrit) (170.215.36.4)
Rating: N/A |
Johnny, Holley built carbs for Motorcraft. The one I have actually has that written on it. It is a standard sized 4 barrel with vacuum secondaries. It came from an auction of school buses and related parts that our local district had when the sold off their fleet as they were having a contractor take over the routes. Once the contract was up, they bought new buses and never renewed the contract. Peter. |