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#1 |
Registered User
Join Date: Nov 2011
Location: USA
Posts: 387
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What would you do with this 454 and what distributor gear is needed?
I purchased a rebuilt 1976 Chevy 454 engine from my brother. The engine was in a 1968 Corvette that he had purchased but he never started it. He doesnt know anything about the engine other than what he was told that it had forged pistons and blah,blah,blah. He didnt know what cam was in it. The engine does not have a distributor in it and no oil pump rod either.
Well I wanted to know more about the engine before putting it into my 1968 Chevy SWB so I dissassembled it down to the shortblock and pulled the cam and here is what I have found out. The engine does have a new hydraulic flat tappet cam and lifters, but there are no numbers to tell you what it is. I tried to measure the cam and the lift seems to measure around .545 on the first lobe,.523 on second lobe,.523 on 3rd lobe and .542 on 3rd lobe of cam. My measuring tool is junk and this is just a estimate at best. How do I know what distributor or distributor gear to run with this cam and lifters? The engine has roller rockers on some 781 cast iron cylinder heads. Inside the engine is very clean with new cast pistons and the cylinders have a very good cross hatch. The pistons are cast and have the numbers 1434 D3 cast into the bottom. I did a search on the pistons and they come back as Silvolite cast pistons.They have 060 or 090 stamped into the top of them and I have included a pic. The pistons seem to be approximately .015 in the hole at TDC. It most likely has the factory cast crank in it. I am not sure what the compression ratio would be. I purchased ARP 135-7901 oil pump shaft to go along with the Melling M71HV oil pump that is already on it. I was thinking about buying a new Howards cam and direct oiling lifters so I know what I have,but I am also wondering if I should just run the cam that is in it along with some brand new Howards direct oiling lifters to try and protect the cam during the break in period? I have heard that BBC are known for cam failure during start up and have heard good things about the Howards direct oiling lifters that supply oil to he cam lobes. Last edited by HeavyHauler; 08-04-2020 at 03:09 PM. |
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#2 |
Senior Member
![]() Join Date: Feb 2010
Location: Falls City, Nebraska "100 Miles From Nowhere"
Posts: 2,219
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Re: What would you do with this 454 and what distributor gear is needed?
The cylinders have been bored .060" over stock. The pistons are a UEM Piston, although cast they are said to be a decent piston that wont frag like a regular cast piston. They're a good middle of the road piston as long as your not winding that motor up to 7K or shooting boost or nitrous to the motor. From the pics they appear to be a low dome and will work great with 781 heads. .015" in the hole is good! The heads are good BBC heads that will make 450 HP in stock form, don't let these drag racers convince you that you need to install bigger valves and port them because unless your racing that motor you don't! One thing I would do is unshroud the valves by matching the tops of each cylinder to the head gaskets, that's an instant 20 HP right there and you never touch the heads. Do some research on how its done and right nows the time while the heads are off. I'll dig up some links and post them if you want, David Vizard is the undisputed expert on these big blocks and shows how simply unshrouding the bores will net 20 HP and help factory heads flow their potential. https://www.musclecardiy.com/cylinde...rmance-part-9/ Never mind all the head work in this write up and scroll down to "Bore Unshrouding" in the pic, the red areas. I'd run the cam you have but beware of the EDM (self oiling) lifters because most are for solid lifter set ups, you have hydraulic lifters and I don't know off hand if EDM lifters are compatible with hydraulic cams. Was that cam and lifters already broke in? In other words, was the motor already broke in when you got it? Heres the important question...Did you keep track of which hole each lifter was removed from so they could go back to hole they were broke in at??? If not, then investing in a new cam and lifters would be a wise decision to insure you don't wipe the cam out and have to disassemble the whole motor for a professional jet washing of the block, heads, and crank. The .525 lift is a nominal lift allowing stock springs and the such and will still make those 781's flow to their potential. Unless your building a race motor I'd keep it hydraulic or hydraulic roller. Comp Cams makes a tool that will cut a groove in each lifter bore that will allow oil to drip directly down onto each cam lobe that does what the EDM lifters do. Another problem with EDM lifters is that laser cut hole is so tiny in many of them that some will clog so beware. I'm running Howards EDM solid lifters in my 439 (427 w/.060" overbore) mated to a Clay Smith solid cam ground for that motor. These particular lifters have .018" oil holes which are considered big holes. I'm running the same exact Melling HV oil pump with welded at the tube, bolted at the pump oil pick up tube. My motor turns 8000 rpm and is a race gas race motor. That tube should be at least "brazed" to the pump body because your motor is externally balanced and they're notorious for shaking those tubes loose. My 427 crank is an internal balanced crank, 454's are not, keep that in mind when you get a flexplate, don't get the internal balanced flexplate! Where are you located? I wish you were close so I could come over and go over some things...You can run any GM V8 distributor in that motor, a small block Chevy dizzy will drop right in and work great as long as it's not bearing down on the oil pump shaft when you lock it down. That's a pretty good set up you got and should run great on pump gas. I cant recall what the chamber volume is on 781's but they are open chamber heads so your CR should be in the 8's maybe low 9's if they've been milled and piston dome volumes fall in the 20's which is low enough for pump gas, high enough to give that big block rumble...
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Michael of the clan Hill, "Two Seventy Two's" 71 1-ton Dually 350 4-Speed 71 C/50 Grain Truck, 350 Split-Axle 4-Speed 02 3/4 ton Express 14 Indian Chief Vintage 1952 Ford 8N, "Only Ford Allowed On The Property" ![]() "Be American, Buy American" ![]() Last edited by Ironangel; 08-04-2020 at 04:35 PM. |
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#3 |
Senior Member
![]() Join Date: Feb 2010
Location: Falls City, Nebraska "100 Miles From Nowhere"
Posts: 2,219
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Re: What would you do with this 454 and what distributor gear is needed?
Get some ISKY's "Rev Lube" to smear on the cam lobes and lifter bottoms. Break the motor in with straight 30w break in oil. Comps Magnum 3/8" push rods with new guide plates and you should be good to go. Bring that motor up to 2000 rpm immediately and keep it there for at least 20 minutes, 25 to be safe. Need to have the dizzy timing close and somebody with a timing gun under the hood ready to fine tune that dizzy while you hold the R's and watch the oil pressure and temp gauges. If something goes south or a leak is detected kill the motor immediately and fix the problem. Where a lot of guys kill their cams is letting the motor idle while a leak is chased or a funny sound shows up. Kill the motor or run it up to 2K and bouncing it up to 2500 occasionally during the break in is ok because the idea is breaking up the splash pattern getting oil to every spot on that cam. Having an infrared temp gauge is good for monitoring each exhaust port tube. The big blocks timing is very much the same as a 350 so 12-15 initial and 35 total all in at 3000 rpm is damn close...Good luck! No apologies for the long writ, Big Blocks are big subjects!
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Michael of the clan Hill, "Two Seventy Two's" 71 1-ton Dually 350 4-Speed 71 C/50 Grain Truck, 350 Split-Axle 4-Speed 02 3/4 ton Express 14 Indian Chief Vintage 1952 Ford 8N, "Only Ford Allowed On The Property" ![]() "Be American, Buy American" ![]() |
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#4 |
Registered User
Join Date: Nov 2011
Location: USA
Posts: 387
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Re: What would you do with this 454 and what distributor gear is needed?
So I can just run a steel distrubutor gear with that hydraulic flat tappet cam that I took out of there?
The engine was never broke in or fired up at all. The cam I pulled out is brand new and so are the lifters. The Howards lifters I was going to buy are for flat tappet hydraulic 454 engines and have a slot machined on the side of the lifter body. They do not rely upon a small hole in the face of the lifter. My oil pump has the pickup tube welded at the base so it should be okay. I kept track and numbered which bore each lifter and push rod came out of even though the engine has never been ran. |
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