cardo0

This is on my original LT1. How much of a press do I need to press the pistons off the rods. Manual Arbor press or 12 ton hydraulic? Haven't looked on U-TUBE yet but any links would be appreciated.

sofakingdom

iTrader: (1)

Probably need a hydraulic to press them apart. They're a pretty significant interference fit.

You can heat the pistons a bit and freeze the pins, to make putting them back on easier; or, bush the small ends and use floaters.

tom3

Haven't done it but I've had pistons changed and the rod ends were bluish looking from heat so I'd guess there would be some serious heat involved.

sofakingdom

iTrader: (1)

Right, I'm sorry, you heat the rods to get the pins into them, not the pistons... my brain got a cramp right then... and yes, people do use A BUNCH of heat sometimes. To the point that it seems like it can't be good for them.

cardo0

Yes I understand you ment to heat the rods for installing rods.. Feedback I'm getting is a 12 ton press maybe marginal. I expect an Arbor press a waist of time for this.

Not sure where this is taking me. Machine shops want like $40 to R&R the rods from the pistons and a Hobo Fake press is around $130 w/o any discount. HF has a H-frame 12 ton and a A-frame 12 ton press. Which is better anyone know??

But I need to remove the rods to weigh them just to see if I can weight match them with an aftermarket rod. If I can't I have to recon the stock rods w/new bolts to use my stock crank. FYI reusing the stock crank saves me from alignhoning/alignboring the block (balancing to) and this is a totally econo build to have a spare motor if needed. Well sorting out the local machine shops to.

AlkyIROC

Pushing pins out is easy providing you're not trying to save the pistons. If you are trying to save the pistons, the need to be pt into a jig so they don't get damaged while the pins are being pressed out.

There is a lot to getting things weight matched for balancing. Rods are weighed at both ends and all the rods are taken down the the lightest weight. Pistons are matched to wrist pins for total weight. Even having to buy a replacement wrist pin can get a different weight. Once everything is matched up including rings, wrist pin locks, rod bolts etc, you get a total bob weight which is put onto the crankshaft to balance it.

Factory balance weight is not very accurate. It's good enough for an OEM engine but that's it.

GeneralDisorder

iTrader: (1)

Generally if you try to do this yourself you will damage the pistons. The investment in tools will not be worth it for one set of rods.

Neither of the harbor freight presses are worth owning. I have the 20 ton in a corner somewhere and you can't get anywhere even close to 20 tons out of it. I have a real press at my shop that has a two stage pump and that's the only way you are getting to 20+ tons with a hand pump (real press has a gauge and still Chinese, but cost about $700) Trust me - not happening with a Chinese bottle jack. The handle would fold in half before you got to 10.

GD

cardo0

U-tube shows some simple jigs for this but don't really have the time to carve one out of some oak wood.

I expect a 565 gram rod should be able to replace a 565 gram rod for a stock balance though I know they could well have different weights at the large and the small ends. This is a econo build and not going to win any bracket trophies. I plan to weight and match the pistons along with the wrist pins for a combined weight. From what I understand lighter is better for the reciprocating weight than heavier. I don't see the ring pack changing total weight much and I'm trying to avoid balancing the assembly. But what is bothering me is it looks like all the cheap aftermarket rods look heavier than stock Chevy rods. Aftermarket rods look so much better and are almost as cheap as reconditioning the stock rods with new bolts (new bolts are $75) but they are advertised 20-30 grams heavier.

cardo0

Well I got only 2 quotes to R&R the rods from the 5 shops I visited. $45 and $80. Not sure what to do. See some real bubba methods on U-tube w/o a press even. Goodson has an installing fixture for $73 - no press needed. But various tools for rod pin removal and can't determine how much and what is needed from Goodson.

GeneralDisorder

iTrader: (1)

I would just take the crank, rods, and pistons into my machinist and tell him to make it happen. Polish the crank journals, check the crank for straight, and balance the whole mess. What are you trying to accomplish by doing it yourself? The stock balancing is not very good...... the weakest link is the rod studs not the rods themselves and if you replace those you have to hone the big ends anyway and rebalance the assembly.

Get some used powdered metal rods from a Vortec if it's a budget build. Supposedly they are quite strong.

GD

cardo0

. What are you trying to accomplish by doing it yourself?

Well I have to look forward as I have two additional 400 blocks for builds so I would really like to be able to R&R the rods myself rather than be a helpless customer to the cheapest machine shop.

A co-worker told me he has removed Chevy rods with a socket and hammer but of course he didn't reuse the pistons or pins.

From what I'm reading a piston fixure is needed along with the correct press-out tool. And a good press.

I guess I need to slow down and sort this all out. Can't find my number stamp set anyways so the rods will stay on the crank until I can number them.

8t2 z-chev

I have done quite a few,it's quite easy-I have a~10 ton press and didn't have to work it too hard to press the pins out-pistons will need to be supported correctly to avoid possible damage during the pressing out-I just used some small square stock placed to take the load-no special jigs.Going on,just heated the rod end with a propane torch and slipped the pin in.Weighed the damaged rods with a cheap digital kitchen scale,replaced with spare rods that matched weight close.

Z51bob

Ditto what 8t2 z-chev says. I've done it with my 6 ton A frame press. Buy a small scale to weigh the rods & match the weights of the old one. But --- be very careful fixturing the pistons & make sure you pre-heat the rods. I used wood blocks under the pistons. Put the pins in the freezer.

cardo0

Thx for sharing folks. It reads like it's much easier to press the pins in than to press them out. When pressing the pins out the rods need support inside the piston somehow. Don't see any of those rod supports for sale. I do see many threaded pin removal tools for sale on line but not sure how well they work. Using the threaded tool could be an all day job.

Goodson markets all tools needed for this including the hydraulic press but cost can run over $2000 easily.

Still sorting this out. Seems unexpected so little information on doing this to the rods and pistons and so many home engine builders..

cardo0

OK, I just watched a nice U-tube video using a 12 ton HF press. The mechanic did use some heat on the rod small end with a hand held propane torch but it looked fairly simple with the right torch tip. He did support the rod (using just a hammer's head) so some kind of support jig will be needed. It does take several minutes for each piston. So I have to maybe weld up a a piston/support then find a pin pressing tool. Maybe then a full hour or 2 getting the pins out.

Do I really want to do this now? Hmmm, 3 engines to build that's at least $150 in machine shop services and it could run to $250.. I'm thinking I should remove the pistons first and build the piston jig before buying anything.

fstarocka

why not buy some cheapo used pistons from somewhere and experiment on them?

cardo0

I visited a local machine shop and he wanted 10 bucks just to separate one rod and piston so I can weigh them. Walked out and stopped at another shop today. Owner offered to press off just 1 rod for free. He did it and I gave him 5 bucks anyways. Kinda funny he didn't even want my old rods when I try to get rid of them - said he has to many as is.

Now have to get the scale out and weight the parts before ordering any replacements.

Thanks for all the help and input everyone.

GeneralDisorder

iTrader: (1)

I can relate as a shop owner - people want to give me old parts all the time. I have way too many parts as it is.

GD

cardo0

Yeah, but to the owner original parts just seem to have more value than they really do. I hate to just scrap them but good ARP rod bolts are 75 bucks. That and buying something to press them in along with recon the rod big end makes shopping for new rods alot more sense.

Now to weigh the pieces and find weights for replacements. Not many rod and piston weights are advertised with them and I have to contact the mfr for that critical information.

GeneralDisorder

iTrader: (1)

You will generally get a range for the weight. When we buy pistons, rods, etc they usually come as a matched set with the weights indicated on the pieces. You will very likely have to weigh and adjust them with a belt sander. Also the total weigh is not the only information - you need to weigh the big end separately from the small end using a rod weight measuring fixture that allows the end not being weighed to freely swing.... it's not as simple as weighing the rod and finding a mate. The distance that weight is from the crank also matters. Total weight needs to be close but you don't want one to have 3 grams more on the small end and 3 grams less on the big end - total weight would be identical - that's still not a match at all.

GD

cardo0

Thx GD. I haven't figured how to match the rod end weights yet. I do know now the piston weights a lot less once I wire brushed out all the crud in the ring grooves. But this ain't much more than a stock rebuild with just bigger cam and some head work. It will never see 7000 rpm. 6000 rpm more likely and I'm trying to save money and not balance the assembly. I will talk to the machinist again but he did say if I weighed all the rods and pistons and rings and bearings he would balance for only $150. Maybe it was just weight the rods and pistons - he didn't specify.

More research needed.

cardo0

So I finally got a rod off a piston. Thought I could share the weights as the stock rods are "pink" rods and not the powder metal rods I expected for an LT1. Rod weight was 599 grams - we can call 600. Piston weight for the hypereutectic piston I have is 533 grams. Piston pin is 143 grams. Add the rings is 44 grams. Finally the rod bearings are 41 grams. Note I scraped off 2 grams of crud for a final weight of 1359 down from 1361 when assembled.

Hope this can help someone else.

NoEmissions84TA

iTrader: (1)

You think too much. What is your time worth? You are trying to save $45.00, but it's going to cost you $450.00 or more in your labor and research.
It is good to know how this is done, but not practical to do it yourself.

GeneralDisorder

iTrader: (1)

+1000. Have a professional with the right equipment do this and spend your time doing whatever it is YOU are skilled at that makes you money. Used powdered metal rods are cheap. Hell I bought a complete Vortec 350 for $200. Everyone wants LS's now. Parts are crazy cheap.

GD

cardo0

Excuse me but I have no idea of what your referring to. I stated before in posts #5 & #11 this is a budget rebuild and I'm sorting out not only the costs but the local machine shops. I wish someone else had posted rod and piston weights so I could use their information but here I provide it to others that may need it.

If either of your posted this information I didn't see it. But I doubt many will have weights for a LT1 hyper piston on a forged pink rod as most were powder metal.

Well I may just post more information then as the build progresses for others interested in a budget build of an LT1. As I constantly read here of owners looking for a budget motor rebuild. And an LT1 has great potential for a TPI swap once the intake manifold is converted to a distributor. I believe TGO is somewhat famous for this conversion and the information along with parts suppliers. Using stock crank and heads the LT1 has great performance potential on a budget. Knowing piston and rod weights is crucial to reusing the crankshaft and saving from align honing and balancing let alone a new crank. I could go to Pick a Part salvage today and find at least a dozen LT1 motors for less than $200. What more do you want?

GeneralDisorder

iTrader: (1)

A used vortec with a cam swap, valve springs, and refresh will perform at least as well and with arguably less work. I got a used 99 Vortec for $200 and didn't have to get it from a pick-a-part. Fellow loaded it in my truck with his forklift for that price. Excellent condition inside too with 171k. Blown intake gasket.

Why would you not align hone the block? That's fundamental. I would do that long before I honed the cylinders. The factory mainline wasn't great nor was the balance. This all needs to be redone.

GD

cardo0

Over $200 to alignhone and it moves the crank higher in the block which inturn loosens the timing chain. I can read you don't understand that and doubt you know how check the crank for a poor alignment either. Once the rods are off and before you touch the main caps all you need to do is check and see if you can rotate the crank by hand. If it moves freely by had it should be good. Alignhoning a crank that turns freely by had is waisting your money and giving you a sloppy timing chain also. But the choice is yours.

Just because you came across a bargain doesn't mean anyone else will. And the vortec heads are iron BTW which are some 40lbs heavier as a pair. Even though they flow better on the intake side they don't flow as well on the exhaust while giving up a whole number of compression using pump gas. Cheap press in studs to.

Sorry man just because your ideas will work doesn't mean someone else can't have as good or better ideas.. Alignhoning is only fundamental to the machine shop taking your money. Some machine shops will tell they do all the machine work you can think of whether they can do it or do it correctly or not.

Like why would I have the assembly balanced when I can match weights? I owned and drove the motor for some 50k mi to 75k mi and vibration was never a problem. Is it gonna go bad now that all the new parts weigh the same as the originals? This is a rebuild not a full race motor. It's gonna mostly cruise to work and back with a few full throttle moments now and then. Alignhoning and balancing is only gonna make me $500 poorer.

Merry Christmas.

GeneralDisorder

iTrader: (1)

The line hone will not make the crank higher in the block by any significant amount. You cut the caps down and shoot the line as low as possible with the bulk of the cut through the caps and only enough to clean up the block side.

Moving freely by hand is meaningless. That could be .0005 clearance, or it could be .004 clearance. Rod bearings live or die on the main bearing clearance, and plastigauge is absolutely worthless. You could be all over the map as to where the clearances are from bearing to bearing with some forcing others to one side or the other causing a loss of oil wedge and rod bearing volume.

I actually check all my clearances with a bore gauge and also verify the crank is straight with a dial indicator on V blocks, and the block using a machinist ground straight edge. That's AFTER I have my machine shop perform a proper line hone.

You won't feel any vibration from a badly balanced engine unless it's REALLY bad. It will just eat itself when it hits the right RPM for a sympathetic vibration to be setup.

You are right about the cost. This is why people typically just buy prepared Dart blocks. Because for a performance application you will be break even on cost and get a much, much better block.

Now - I won't be doing this on my Vortec (I will check that it's not crazy out of whack) because it's going in my truck. It will never see north of 4500 rpm. For a performance application I would take it much farther.

GD

cardo0

Alignhoning does make the crank move higher no matter how little metal they remove. If you can't see this then I can't help you. Yes they should minimize the amount removed you end up with what ever they give you even on a hangover Monday. If you care to look you will find timing sets shortened in small increments for this. But good luck finding one for GEN II LT1.

So now you tell me I can't use plastigage but have to buy V-blocks and mics accurate to a tenth. Or else pay a shop to do this.. Get real dude. V-blocks and accurate mics maybe better but again get real.
If the bearing clearance was only 5 tenths you shouldn't be able to turn it by and and if it has 4 thou clearance the bearings would be wiped. Besides you need to verify it turns freely by had again after you set the new bearing clearance with crank polish and new bearings.

Out of balance harmonic? That's funny!. I scraped 2 grams of crud off the piston that I measured and I bet there's at least another 5 grams of crud baked on just the piston that I can't brush off. And how much oil is hanging onto the crank and rods normally? Again get real this is a DD not a track motor operating over 7000rpm for hours at a time.
Back in time when labor was cheaper than parts (before the 70's) shops would bore just one cylinder and install a larger piston to get another 100,000miles from that motor.

So go ahead and spend for max performance on low performance build. All it will hurt is your bank account.

Oh and BTW an aftermarket block still needs all the machine work.

GeneralDisorder

iTrader: (1)

They make oversized OD bearings so that you can retain the stock location of the crank after a line hone.

Yes there is a lot of tolerance on these engines. You will get away with misalignment, poor balance, and random clearances for a little while. You will get that metallic swirl in the oil that everyone likes to call "normal" as the bearings wear in to a nice wiped out finish that will last 20-30k before it goes nuclear.

And yeah - back in the day they did silly things like oversize one hole, grind cranks in the car, knurl pistons, etc. But your romantic memory of that junk lasting 100k is in a galaxy far, far away. The original engine might have made 100k. And then you got another 25k or 30k out of these labor intensive "rebuilds". And in any case these were low RPM engines that weren't subject to the forces even that LT1 will be under.

It's just better to invest in the tools to do it right or pay someone that has them. I build engines nearly every day in a 5 bay shop and I see what happens when it's not done correctly. I've made these mistakes and it cost me a LOT of money and time. It's not worth it to do it the wrong way and then do it again the right way. Trust me that just plain sucks.

GD

cardo0

Owners do re-ring and re-bearing overhauls all the time. Sometimes adding a rebore and piston kit to. To say that they need to alignhone and balance the motor is hog wash!. But I do believe you learned how to build motors the hard way.

Good night.

HINKSON AUTO

No one uses over size bearings on the main line when align honing a block, Give me a break LOL. I have two line hone tables and to date have never over sized a main line yet.

If your dealing with OEM blocks Center to center distances are all over the place.

I blue print blocks and build performance engines for a living and have state of the art machinery. Here is a little bit of what I do.

http://www.chevelles.com/forums/148-...ing-block.html

If your using junk bore gauges like the cheap mitutoyo ones to check bearing clearances then I would have to say plastigage is far more accurate.

cardo0

Ahhh. Sanity arrives.

HINKSON AUTO

That is not your bob weight the big end of the rod and rod bearing are figured double when figuring out a bob weight plus you have to add for oil.

cardo0

Yes I'm not there yet but when ordering rods all I can get is total weight. Can I do better than that?

HINKSON AUTO

GM crank to cam center lines are all over the place. I have found them off .016 before. Thats why GM line bores the cam tunnel with cam bearings in place to correct for there poor machine work. Buy an OEM block from GM they all come with cam bearing installed. I have taken cam bearings out a new block stood them up on the bench and they roll to the heavy side HMMM

Cloyes makes a variety plus or minus chains if you need one.

GeneralDisorder

iTrader: (1)

Yeah the factory line hone is $hit.

You only need look at the bearing inserts to tell that. I've found all kinds of weird mix-match bearings tearing down engines. Seemingly ran ok but you would have to buy three or four sets of bearings to put one engine together the way GM did things.

I was just saying they *do* make oversized OD bearings. My machinist has mentioned this possibility for some applications. We haven't had to do that - just mentioned it in response to cardo0 saying he couldn't find chains to correct for a line hone. Seems unlikely to me but then I've not looked for them for an LT1 (why would it be different?).

My bore gauges are Starrett. The problem I have with plasti-gauge is that it doesn't really tell the whole story - it only checks clearance in one location when ideally it should be checked in the thrust direction but also at 45 degrees to the thrust to insure the oil wedge is being setup properly in the direction of rotation.

GD

HINKSON AUTO

If those are rigid finger Starrett bore gauges and not floating finger bore gauges like the Sunnen ones throw them in the dumpster.


No such thing as a factory line hone GM OEM V-8 Blocks are alllllll line bores only.

Again if your using junk bore gauges plastigage can be more accurate.

Here is a pic of a bore gauge that should not be used for checking bearing clearances. Those type bore gauges are good for measuring round bores only.

HINKSON AUTO

You need that fixture to hold the rod on the pin end when you weigh the last big end while the rod is still in the fixture zero the scale and from there you can set the whole rod on the scale and it will give you the pin end weight. Saves alot of time.

If you need a pic of a Bob weight Card I can put one up if needed.

sofakingdom

iTrader: (1)

Carl, can't see your photos... photobucket doesn't allow 3rd party site use anymore.

HINKSON AUTO

Go to my F/B page and look over my photo albums.

https://www.facebook.com/cncblocks.northeast

GeneralDisorder

iTrader: (1)

Huh. Well my measurements agree with the specs given by my local machinist that performed the line hone for me.

What is the issue exactly with the type of bore gauge pictured?

GD

HINKSON AUTO

Rigid finger bore gauge could be Met or a Starrett who knows. Junk for measuring housing bores with bearings installed.

Whats your machinist using???

I use a ll Sunnen Bore gauges nothing but the best LOL

GeneralDisorder

iTrader: (1)

I understand that you believe they are junk and I'm willing to entertain that hypothesis but what exactly about them causes you concern? Even some empirical evidence would be ok. A technical explanation of why they don't work well for this type of measurement would be great.

I would have to ask my machinist what he uses but he's pretty well respected and I've had him do close to 20 engines for me and not had any issue with his work. I'm sure his cost more than mine

BTW - I'm seriously considering one of your Dart blocks for my Trans Am. Your work comes highly regarded and looks beautiful. I'll PM you when I'm ready for it. Have to recover from the holidays first....

GD

HINKSON AUTO

This link has a lot of good info on bore gauges and measuring bearing clearances. You will see what I am talking about.

http://www.performanceboats.com/gn7-...learances.html

GeneralDisorder

iTrader: (1)

Well I read through that thread and there doesn't seem to be much consensus except don't buy cheap measuring devices and whatever you use, you best be confident and repeatable with it. Which my bore gauges have been for me. I'm not seeing any technical explanations detailing exactly why they would be inaccurate. This is the one I have:



I haven't had any issue with it. My results are repeatable and agree with the measurements I get from the machine shop as well as factory specs on new parts. I do a lot of Subaru engines using brand new blocks, cranks, rods, etc from the dealer and aftermarket and I feel confident that I'm accurate to within a couple of tenths. We typically want the main bearings to be around .001" due to aluminium block expansion. We run them up to about 600 to 700 HP and I've not had a bottom end issue yet in 10 years of building them.

GD

HINKSON AUTO

Rigid fingers like that are great for checking housing bores that are round. But when checking housing bores with bearings installed and bearings have eccentricity built into them that where rigid finger bore gauges give you a false reading.

If you could put a .0002 feeler gauge under your rigid finger bore gauge it would change the reading of your gauge. Sunnen bore gauges have floating fingers. You could put a .050 feeler gauge under a Sunnen bore gauge it won't change.

I have had a lot of bore gauge wars in my shops over they years I can tell you what works and what does not.

Reread that thread you must of over looked a lot posts like 62 and 67

GeneralDisorder

iTrader: (1)

Perhaps I will look into the sunnen models. I'm not against a better design. Or spending money on tools.

GD

HINKSON AUTO

It would be money well spent.

GeneralDisorder

iTrader: (1)

Ok so reading your post - forgive my ignorance on the Sunnen design but when I'm measuring bearing inserts I always want to see that eccentricity to insure it is even. I generally check it on a 45 degree to the thrust direction to insure that the alignment of the caps is not shifted. If the Sunnen design ignores this them how would I see a potentially catastrophic bearing cap alignment issue. Granted it would shrink the thrust measurement but it's very hard to tell which direction the cap has shifted without checking the 45's.

GD