73-87chevytrucks.com
73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: bake315 on December 04, 2009, 03:32:37 pm
-
I have to tell you - I hadn't planned on doing this yet, but, as you'll be able to see from the photos, this engine doesn't have much left in the way of secrets.
I already had the front core support, bumper, etc. removed, so I figured it was easiest to just remove the engine and tranny as one unit, plus, I wanted to install new seals on both ends of the tranny anyway.
Got it into the garage and on to the engine stand. Pulled the heads first. No surprises there, no evidence of impending failure. Flipped the motor, and began disconnecting the rods from the crankshaft. Nearly every rod bearing had what appeared to be normal wear - except for #8, there was significant scoring there. Definitely helps to validate my decision to completely tear it down. Pushed each piston on through, taking great care not to scratch the crank. Once these were out, I turned my attention to the crankshaft bearing caps. All of these bearings seemed to show normal wear, so life is good in crankshaft land. I will have the crank polished before re-installation, in any case.
So now, I have a blank canvas, if you will. When I started all of this, I was just going for a cam upgrade, but now that I'm all in, it sort of raises all sorts of possibilities. I haven't as yet had a chance to measure cylinders yet - so I don't really know where I'm going yet displacement-wise. So for now, all I know is it's headed for a trip to the machine shop in about 2 weeks.
What I have in hand so far to put on/in the motor:
New timing set (EDL-7809)
New Performer Plus cam (EDL-2162)
New cam bearings (FEM-1404M)
Performer 2-0 intake
Carter 625cfm carb
Ceramic long tube headers
This basic list was where I was going with my original plan before discovering the wear problems. Going forward I'm thinking I'd like to take the opportunity to tweak things a little, without having to, say, buy another cam & lifter set. I'm going to have the heads serviced too, so the opportunity to get valves & springs that are the best match for this cam would be a priority. The piston skirts are lightly scuffed, but connecting rods and wrist pins appear fine (machine shop will verify this). I want to go with a forged piston for peace of mind, even though I won't be racing this truck, and considering the relatively small difference between cost for the domed versus the flat (at least at what I've been looking at on Summit's site) I thought it wouldn't hurt to go domed and get a little more out of it.
The machine shop guy says that he'll need to have the pistons when he does the boring/honing, so I guess I'm going to need to know how far over standard bore I'm wanting to go (assuming that the block has never had a lower end rebuild). I don't want to go 40 over, for example, if I'm not going to realize a benefit, because I'd like to have the option to rebuild it later on, maybe more than once, you know? Anyway, to get back to the point, I assume that I need to use a dial caliper or equivalent to measure the current bore diameter. Does it matter whether I check it near the top, or should it be somewhere in the middle? And, I assume I should check all of the cylinders, and order based on whatever the largest measurement is, correct?
Pics to follow later.
Thanks,
bake315
-
I'd rebuild a Q-Jet before going to a 625 cfm Carter -- get the best of both worlds. Everything else seems fine for a nice low-end torque machine, but Vile has said that he's had trouble with Edelbrock cams (as far as durability). The last cam his 454 ate was an Edelbrock RPM flat tappet. Also, you might look into "armor-faced" lifters (Comp and GMPP offers them) and possibly even having the cam nitride-hardened if 100K+ mile durability is of the utmost importance to you.
-
Event you have a good memory! I'd go with a roller cam setup and before you choose your pistons tell us more about your heads? What's this going in and what's it being used for?
-
Take the block to the machine shop and have him tell you which pistons to order size wise. If the engine has been bored, the pistons should have the over size stamped on the top. It may take a little cleaning, but if it was, the stamp would be there. If its stock,.030 should be ok. Id have the shop check them just incase. They usually dont charge to check because it only take a minute to check. I wouldnt worry about .040 or even .060 over on a bigblock. They are pretty beefy. Theres a guy that owns a machine shop here that bores the .100 over all the time and doesnt have any issues.
-
If you do decide to go roller, Lunati offers some of the least expensive retro-fit roller lifters I've ever seen:
https://www.lunatipower.com/ProductGroup.aspx?id=311&cid=28&pid=2
-
I'd rebuild a Q-Jet before going to a 625 cfm Carter -- get the best of both worlds. Everything else seems fine for a nice low-end torque machine, but Vile has said that he's had trouble with Edelbrock cams (as far as durability). The last cam his 454 ate was an Edelbrock RPM flat tappet. Also, you might look into "armor-faced" lifters (Comp and GMPP offers them) and possibly even having the cam nitride-hardened if 100K+ mile durability is of the utmost importance to you.
Yeah, the Carter was just sort of a leftover from the truck when I bought it. I was definitely going to go to something else at some point in the near future. I had thought about Edelbrock, but then I read where Vile mentioned that they'd been rebranding their products, so that gave me a little bit of pause there.
Vile, you'd actually suggested the Edelbrock cam, back when I started out on this gig - don't know if that was before or after you'd heard about the rebranding. I didn't know about the nitride hardening option, I'll look into that a bit more. Fortunately, I don't count on this truck ever being a daily driver, so I don't know that it'd ever see 100k - at least on my watch. Other than tooling around a bit on the weekends, and pulling a bay boat or travel trailer occasionally, duty will be relatively light.
The heads are the stock, oval port heads that came on the motor. It's out of the '73 in my sigline.
Got back my bore measurements (hope I read it right), 4.2485. I'm going to have a look at one of the pistons again - I don't recall seeing a number stamped on them, though.
-
Just took a look at the #8 piston. Only number stamped on top was an 8, like what is stamped on the rod and cap. So that tells me that it's stock, I guess.
-
Edelbrock flat out told me they just stick their name on the cams although they do design the profiles. So you're essentially just paying for the name. Do you have the casting # on the heads?
-
Do you have the casting # on the heads?
Yes, #353049 for both.
-
You can go with a domed piston, and do some porting on those heads. If you have rotators get eliminators.
-
If you have rotators get eliminators.
Um... ya lost me on this one. Still a noob, here!
Oh wait... for the valves so that they'll rotate and not get hung in one spot?
-
Actually, I think they are there to break and cause valvetrain failure.
-
Actually, I think they are there to break and cause valvetrain failure.
Even the Howards Cams eliminators? They look pretty beefy to me.
-
Actually, I think they are there to break and cause valvetrain failure.
Even the Howards Cams eliminators? They look pretty beefy to me.
LOL, I meant factory rotators. At least that's what I've heard. That's why it is so popular to eliminate them. Yes, the eliminators are bulletproof as they are just a solid steel spacer.
-
Rotators aren't for high RPM operation. Valve float stops your engine from making power. Definitely get rid of them if you've got em.
-
Do you have the casting # on the heads?
Yes, #353049 for both.
good head and the flow pretty good.. for stock
stock valves are 2.065/1.72 havent cc'd the chamber.. do that monday. iirc the are between 119-122cc
i am in the middle of rebuilding my 454..
.060 over
speed pro 10.5cc dome
.020 in the hole
i am shooting for 9:1 compression
put new guides opened the exhaust up to 1.88
camshaft im running a 208/214@050" .475/.500
low rise dual plane intake and old edelbrock 0396(before the preformer came out)
your edelbrock camshaft should put you close to 375hp/500tq at the FW @ 9:1
comp cams sells a spacer that is drop in to replace the rotaters its ~30.00$
this is a dyno sheet of my BBC before it died.. with ~8:1cr edelbrok 0396 intake, headers dual 2.5", 208/214* cam and ignition sytem stock 049 casting heads and a 600cfm preformer carb.. the dip in the graph @ ~2400rpm is the secondaries opening up
(http://c3.ac-images.myspacecdn.com/images02/104/l_9a1746997a474863906e2de6860f23ca.jpg)
-
Just took a look at the #8 piston. Only number stamped on top was an 8, like what is stamped on the rod and cap. So that tells me that it's stock, I guess.
Not stock, someone has had that motor apart before. GM does not stamp the rods with numbers. You might have .030 over already. The only stamps should be there are on the pan rail and they use letters.
Steve
-
Not stock, someone has had that motor apart before. GM does not stamp the rods with numbers. You might have .030 over already. The only stamps should be there are on the pan rail and they use letters.
Steve
I see. That's a little disappointing, though in makes sense in some respects. One question though - when I measured (from the top of the cylinder) the bore size, I got something on the order of 4.2485. If stock bore on a 454 is 4.25, is it reasonable that someone simply installed new pistons and rings at some point, without actually re-boring? Granted my caliper was only a $25 digital from the local auto parts, but still....?
-
Your caliper is not as accurate as it needs to be for machining but will get you in the ball park. Measuring at the top of the cylinder is not where you want to measure either due to ridge wear. It's obviously standard bore. You can buy telescoping gauges dirt cheap and get better measurements.
Many factory engines ARE numbered especially if there was an error in the assembly process which required the engine to be pulled aside and torn down again. I've seen factory engines that had only one oversize piston. So not to discredit you joe but you will find factory installed unmolested numbered chevy engines. I'm not saying that is what you have there bake but if someone was in there they kept it standard bore nevertheless.
-
Okay. Thanks for the help so far guys. So, I'll pick up a set of those eliminators today. Can I continue with the stock valves & springs, or do I need to account for the thickness of the eliminators?
-
The whole purpose of the eliminators is to take up the missing thickness of the rotators. Basically, they are just thick shims.
-
The whole purpose of the eliminators is to take up the missing thickness of the rotators. Basically, they are just thick shims.
OK, good. Thanks!
-
Arrrgh! Nobody has the pistons I want. >:(
http://www.summitracing.com/parts/TRW-L2399F40/
-
Okay, I think I've settled on a rebuild kit.
http://www.summitracing.com/parts/FEM-CSMHP771-311/
I'm only going .030 over, but only because it was going to literally be Christmas before I could get the .040 kit - maybe.
Can anyone tell me what the volume in cc's my stock heads are?
-
Okay, I think I've settled on a rebuild kit.
http://www.summitracing.com/parts/FEM-CSMHP771-311/
I'm only going .030 over, but only because it was going to literally be Christmas before I could get the .040 kit - maybe.
Can anyone tell me what the volume in cc's my stock heads are?
unless you planing on getting your crank turned that the wrong kit...
and it have 50cc domes which is effing huge..and barely pump gas compression..
10-20cc dome will land you 9-10:1 compression... 049 head run a 120cc chamber
im running a 10.5cc dome and i am are 9:1 with same heads
-
Okay, I think I've settled on a rebuild kit.
http://www.summitracing.com/parts/FEM-CSMHP771-311/
I'm only going .030 over, but only because it was going to literally be Christmas before I could get the .040 kit - maybe.
Can anyone tell me what the volume in cc's my stock heads are?
unless you planing on getting your crank turned that the wrong kit...
and it have 50cc domes which is effing huge..and barely pump gas compression..
10-20cc dome will land you 9-10:1 compression... 049 head run a 120cc chamber
im running a 10.5cc dome and i am are 9:1 with same heads
Thanks, Adam. This is exactly what I needed to know. I'm no mechanic, and this is my very first build, so I'm needing to know these details.
So you're saying that with my chamber size, I need to keep the dome under a 20cc maximum in order to have a engine that is practical for the street, is that right?
The crank will be headed to the shop with the block and the pistons, so I'd imagine that he'll do what needs doing based on what I give him.
-
under 20cc dome yes. flat top will run between 8-8.5:1
talk to the machinist. let him know what you are after. and he will know best route for you... or let him know your budget limit and what type of service its goign to be.. what rpm will it be running at... then you can prioritis the machine work... bore, deck, main bore,reconditioning the rods, decking the heads is an option as well. it will also take a couple cc out of the chamber size
id you do get the block decked. only take off enough to clean the surface up to get it in spec. another thing is they "should" do is squaring the block.. this is cutting the deck so it is parrellel to the crank axis and both are 90* from each other.
if you have the rods recon'd... it is a good idea to to get new rod bolts.. mainly arp.. ~60.00 buck is cheap insurace to make sure the rods bolts dont break. when you running them..
heads... stock is 2.065/1.725.. common upgrade is 2.19/1.88 def check valve guide as well. i left my intake 2.065 and upgrade to 1.88 inthe exhaust.
.. if you like answer these question and you will have a basic idea of what your after and can afford..
1. budget
2. what is the duty for the engine... towing. street strip?
3. how much power you want?
-
under 20cc dome yes. flat top will run between 8-8.5:1
talk to the machinist. let him know what you are after. and he will know best route for you... or let him know your budget limit and what type of service its goign to be.. what rpm will it be running at... then you can prioritis the machine work... bore, deck, main bore,reconditioning the rods, decking the heads is an option as well. it will also take a couple cc out of the chamber size
id you do get the block decked. only take off enough to clean the surface up to get it in spec. another thing is they "should" do is squaring the block.. this is cutting the deck so it is parrellel to the crank axis and both are 90* from each other.
if you have the rods recon'd... it is a good idea to to get new rod bolts.. mainly arp.. ~60.00 buck is cheap insurace to make sure the rods bolts dont break. when you running them..
heads... stock is 2.065/1.725.. common upgrade is 2.19/1.88 def check valve guide as well. i left my intake 2.065 and upgrade to 1.88 inthe exhaust.
.. if you like answer these question and you will have a basic idea of what your after and can afford..
1. budget
2. what is the duty for the engine... towing. street strip?
3. how much power you want?
Good stuff. Mostly this truck is going to be a fun cruiser, that I may want to "horse around" a bit with sometimes, but there will be times when it may be needed to pull a boat, travel trailer, whatever... So I'll plan on that. I will be getting the rods reconditioned, so thanks for the tip on the bolts. As far as the budget goes, I don't want to break my bank, but I don't want to cut corners either, so it will be whatever it ends up being. There's still the rest of the truck to consider, so I don't want to drag this out too far, financially.
Are you running forged, or hyperuetectic pistons?
-
OK, so I've spent the afternoon trying to determine how best to go at this. Here's what I've come up with:
According to what malibu795 is telling me (huge help), my 049 heads have 120cc chambers. If I run a -20cc domed piston, my compression ratio should run somewhere in the neighborhood of 10:1.
According to Summit, the rebuild kit that utilizes -25.7cc domed pistons claims an approximate compression ratio of 9.78:1 with 116.9cc chambers.
Therefore, if I use this kit with 120cc heads, wouldn't that leave me really more or less in the same 10:1 ballpark?
-
How bout http://www.summitracing.com/parts/TRW-L2349F30/
-
How bout http://www.summitracing.com/parts/TRW-L2349F30/
yeah quick check.. and a thick gasket 4.37x.045" and those piston 29.4cc domes and no decking of either head or block will come in right about 9.8X:1
-
How bout http://www.summitracing.com/parts/TRW-L2349F30/
yeah quick check.. and a thick gasket 4.37x.045" and those piston 29.4cc domes and no decking of either head or block will come in right about 9.8X:1
Well, if these will do the job, then I'll run with it. Gents, I thank you. I'll keep you posted on the progress.
bake315