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Rebuild or heck NO?


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I have and old engine that got a little tired and sitting here as a possible spare for the last 1-2 years. It had decent compression, but not great and we replaced it as it felt down on power. We found out it was also a faulty knock sensor that was pulling timing so the engine is still OK so a good option to rebuild it. I am just debating if it is worth doing, a Camry V6. I have not rebuilt one of these yet as the junk yard ones are $450-650 and blown up like 3-4 so far (all from oil starvation from no accusump, accusump with no air pressure in it as it leaked, oil line pulled away and no oil and one we do not know why). Now they are getting harder to find with lower mileage ones.

 

I guess the real question is what gains would I get realistically if I rebuild it (5hp, 10hp, more, less) and do some basic things and how reliable should it be? I am concerned I would do something wrong as you never know, but you never know how long a stock junkyard camry motor will last also.  My thoughts were new bearings (maybe kings), new rings, hone the cylinders, clean up the block. New oil pump, water pump, timing belt and parts there, gasket set of course. I could do a slight port and polish to just get rid of casting mistakes and match the cylinder head to the lower intake and that match that to the upper intake. I can not really shave the heads to raise compression (stock 10.5) like a 4cyl or inline 6cyl as it would cause my timing belt to be off and also the intake lower to not match up well. I could port the lower intake to match up, but might have issues with it bolting down and lining everything up if shaved. I am not sure how much compression it would rise anyway and if worth it. I would think if we got pistons made for higher compression that should have some point value, but I did not see anything in the rules that said it so not sure on that one and the amount it should add or is that just a simple big no no. 

 

I guess my questions I have and debate in my head is

 

1-Is it worth rebuilding the motor with cost and time?

 

2-What hp gains would I get, if any, if rebuilt?

 

3- Do you all think it is more reliable rebuilt or less and why?

 

Thanks for the help as I ponder things like and they do not just go away.

 

Now let us chat about it.

Troy

 

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1. Yes. See #2 and #3.

2. If you don't mess something up, fresh always makes more power than tired.

3. If you don't mess something up, fresh is always more reliable than tired.

 

It's up to you to decide whether you can rebuild it and not mess something up. :)

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Then again, maybe you want some specifics.

  • I went through my 80,000 mile GM V6 before putting it in the Fiero. Did ARP rod bolts and head studs, Cometic head gaskets, a new timing chain, rings and gaskets and reused everything else. Pretty sure the ARP rod bolts were instrumental in the engine surviving a 7600 rpm downshift overrun, happened at about the 40 hour mark. Worth the rebuild right there.
  • Initial leak-down after some dyno run-in time was 4%; checked last week after about 80 hours of racing, still at 4%. Redline 40wt after the dyno runs to break it in.
  • I recorded the roll-over torque during the build as I do with all my engines to check ring drag: 9 ft.lbs on the short block. Haven't rechecked but that's pretty good already.
  • Getting oil coming past the seals and guides at idle now, not surprised considering the constant high (for a pushrod engine) rpm. Did bronze guide liners like usual for my race engines but they usually only get about 30 hours between freshening so interested to see what they look like now.
  • Made good use of my die grinder and carbides, then a nice valve job. Still sealing very well as evidenced by the 4% leak.
  • Properly baffled oil pan with windage tray, ran 1 quart overfull, no accusump and no bearing issues. That's going by the oil filters that I cut open after each race, I'll probably have a look at them in the near future.
  • Timing chain has about 4 degrees of slop now, no tensioners so wear goes up quicker once it starts.
  • I measured the deck height and got the right thickness gaskets to get 0.035" quench.

My daughter wants to use this engine in her street Fiero, so we'll go through it again. Shouldn't have to touch the bottom end, just freshen up the heads again and take care of the timing chain and water pump. Most likely will reuse the head gaskets and of course the head studs, I don't like TTY anyway. I find on pushrod engines that heads need freshening 2-3 times more often than the short block to maintain power. Best combo for power is a seasoned short block with freshened heads, minimum internal friction and best flow.

 

P.S. My philosophy on accusumps is that if you're depending on them for oil pressure you'll eventually have an engine failure. Keeping the oil pump pick-up covered with oil beats trying to push oil into the engine while it's trying to pump air.

 

Edited by mender
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I would think you easily be able to gain 5-10hp, more like 20 if you do a few more things, porting the heads will help. For more compression you could mill the heads or deck the block. Not sure what "hot-rod" parts are available for that application but if you want to get crazy upgrade your cams... even a stock rebuild would pick you up over a tired motor.

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7 hours ago, MR2 Biohazard said:

I have and old engine that got a little tired and sitting here as a possible spare for the last 1-2 years. It had decent compression, but not great and we replaced it as it felt down on power. We found out it was also a faulty knock sensor that was pulling timing so the engine is still OK so a good option to rebuild it. I am just debating if it is worth doing, a Camry V6. I have not rebuilt one of these yet as the junk yard ones are $450-650 and blown up like 3-4 so far (all from oil starvation from no accusump, accusump with no air pressure in it as it leaked, oil line pulled away and no oil and one we do not know why). Now they are getting harder to find with lower mileage ones.

 

I guess the real question is what gains would I get realistically if I rebuild it (5hp, 10hp, more, less) and do some basic things and how reliable should it be? I am concerned I would do something wrong as you never know, but you never know how long a stock junkyard camry motor will last also.  My thoughts were new bearings (maybe kings), new rings, hone the cylinders, clean up the block. New oil pump, water pump, timing belt and parts there, gasket set of course. I could do a slight port and polish to just get rid of casting mistakes and match the cylinder head to the lower intake and that match that to the upper intake. I can not really shave the heads to raise compression (stock 10.5) like a 4cyl or inline 6cyl as it would cause my timing belt to be off and also the intake lower to not match up well. I could port the lower intake to match up, but might have issues with it bolting down and lining everything up if shaved. I am not sure how much compression it would rise anyway and if worth it. I would think if we got pistons made for higher compression that should have some point value, but I did not see anything in the rules that said it so not sure on that one and the amount it should add or is that just a simple big no no. 

 

I guess my questions I have and debate in my head is

 

1-Is it worth rebuilding the motor with cost and time?

 

2-What hp gains would I get, if any, if rebuilt?

 

3- Do you all think it is more reliable rebuilt or less and why?

 

Thanks for the help as I ponder things like and they do not just go away.

 

Now let us chat about it.

Troy

 

 

My Dad and I did a full motor in 2011 or 2012. I am glad I did it so I understand exactly how it works. We purchased a hone for a drill and a few tools we needed to make it work. We used one of the ebay rebuild kits that was complete with everything. 

 

Kind of like this: http://www.ebay.com/itm/Engine-Rebuild-Kit-Fits-96-00-Honda-Civic-del-Sol-Civic-1-6L-SOHC-D16Y5-D16Y8-/281670360252?hash=item4194dc9cbc:g:LQ4AAOSwDNdVqVcL&vxp=mtr

 

When we were finished there was no noticeable power increase.It ran OK for a couple races and then tossed a rod at Road America. I think we had 5 or so mis-shifts to 10k RPM, so the engine was not really at fault for throwing the rod. The next engine was a JDM import engine for ~$600. I think that engine ran 10+ more events and is still going strong. 

 

Now that I know what is involved, I much prefer running an unopened engine for cost and time involved. 

 

 

 

 

 

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6 hours ago, mender said:

Then again, maybe you want some specifics.

  • I went through my 80,000 mile GM V6 before putting it in the Fiero. Did ARP rod bolts and head studs, Cometic head gaskets, a new timing chain, rings and gaskets and reused everything else. Pretty sure the ARP rod bolts were instrumental in the engine surviving a 7600 rpm downshift overrun, happened at about the 40 hour mark. Worth the rebuild right there.
  • Initial leak-down after some dyno run-in time was 4%; checked last week after about 80 hours of racing, still at 4%. Redline 40wt after the dyno runs to break it in.
  • I recorded the roll-over torque during the build as I do with all my engines to check ring drag: 9 ft.lbs on the short block. Haven't rechecked but that's pretty good already.
  • Getting oil coming past the seals and guides at idle now, not surprised considering the constant high (for a pushrod engine) rpm. Did bronze guide liners like usual for my race engines but they usually only get about 30 hours between freshening so interested to see what they look like now.
  • Made good use of my die grinder and carbides, then a nice valve job. Still sealing very well as evidenced by the 4% leak.
  • Properly baffled oil pan with windage tray, ran 1 quart overfull, no accusump and no bearing issues. That's going by the oil filters that I cut open after each race, I'll probably have a look at them in the near future.
  • Timing chain has about 4 degrees of slop now, no tensioners so wear goes up quicker once it starts.
  • I measured the deck height and got the right thickness gaskets to get 0.035" quench.

My daughter wants to use this engine in her street Fiero, so we'll go through it again. Shouldn't have to touch the bottom end, just freshen up the heads again and take care of the timing chain and water pump. Most likely will reuse the head gaskets and of course the head studs, I don't like TTY anyway. I find on pushrod engines that heads need freshening 2-3 times more often than the short block to maintain power. Best combo for power is a seasoned short block with freshened heads, minimum internal friction and best flow.

 

P.S. My philosophy on accusumps is that if you're depending on them for oil pressure you'll eventually have an engine failure. Keeping the oil pump pick-up covered with oil beats trying to push oil into the engine while it's trying to pump air.

 

 

I think you are the exception to the rule since this type of work is your trade. It makes sense for you to freshen your engines with the skills and tools you have. 

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10 minutes ago, red0 said:

 

My Dad and I did a full motor in 2011 or 2012. I am glad I did it so I understand exactly how it works. We purchased a hone for a drill and a few tools we needed to make it work. We used one of the ebay rebuild kits that was complete with everything. 

 

Kind of like this: http://www.ebay.com/itm/Engine-Rebuild-Kit-Fits-96-00-Honda-Civic-del-Sol-Civic-1-6L-SOHC-D16Y5-D16Y8-/281670360252?hash=item4194dc9cbc:g:LQ4AAOSwDNdVqVcL&vxp=mtr

 

When we were finished there was no noticeable power increase.It ran OK for a couple races and then tossed a rod at Road America. I think we had 5 or so mis-shifts to 10k RPM, so the engine was not really at fault for throwing the rod. The next engine was a JDM import engine for ~$600. I think that engine ran 10+ more events and is still going strong. 

 

Now that I know what is involved, I much prefer running an unopened engine for cost and time involved. 

 

 

 

 

 

 

I think it also depends what parts you're using to rebuild with. An eBay kit is not going to be as reliable as OEM parts. Sorry to break this to everyone.  I prefer using high quality OEM parts as an engine is the heart of the car. 

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27 minutes ago, Crank Yankers Racing said:

I think it also depends what parts you're using to rebuild with. An eBay kit is not going to be as reliable as OEM parts. Sorry to break this to everyone.  I prefer using high quality OEM parts as an engine is the heart of the car. 

 

http://www.ebay.com/itm/Engine-Pistons-NPR-Ring-Set-Honda-Civic-Del-Sol-1-6L-DOHC-VTEC-B16A2-B16A3-/141000131900?fits=Make%3AHonda&hash=item20d443453c:g:ghgAAOSwF1dUSn6Q&vxp=mtr

 

Well, there is a difference in parts on Ebay. Look at this piston, ring, wrist pin set. $60 including shipping, and made in Japan.  

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4 minutes ago, Team Infiniti said:

We are not talking about 50 yr old American engine tech, do not expect to find many mistakes/casting mismatch/roughness.

 

This is what I was hearing back in the eighties and nineties  All the prep shops that were used to doing American and British stuff were finding there wasn't much they could improve on the Japanese engines, everything fit so much nicer.

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7 hours ago, mender said:

Then again, maybe you want some specifics.

  • I went through my 80,000 mile GM V6 before putting it in the Fiero. Did ARP rod bolts and head studs, Cometic head gaskets, a new timing chain, rings and gaskets and reused everything else. Pretty sure the ARP rod bolts were instrumental in the engine surviving a 7600 rpm downshift overrun, happened at about the 40 hour mark. Worth the rebuild right there.
  • Initial leak-down after some dyno run-in time was 4%; checked last week after about 80 hours of racing, still at 4%. Redline 40wt after the dyno runs to break it in.
  • I recorded the roll-over torque during the build as I do with all my engines to check ring drag: 9 ft.lbs on the short block. Haven't rechecked but that's pretty good already.
  • Getting oil coming past the seals and guides at idle now, not surprised considering the constant high (for a pushrod engine) rpm. Did bronze guide liners like usual for my race engines but they usually only get about 30 hours between freshening so interested to see what they look like now.
  • Made good use of my die grinder and carbides, then a nice valve job. Still sealing very well as evidenced by the 4% leak.
  • Properly baffled oil pan with windage tray, ran 1 quart overfull, no accusump and no bearing issues. That's going by the oil filters that I cut open after each race, I'll probably have a look at them in the near future.
  • Timing chain has about 4 degrees of slop now, no tensioners so wear goes up quicker once it starts.
  • I measured the deck height and got the right thickness gaskets to get 0.035" quench.

My daughter wants to use this engine in her street Fiero, so we'll go through it again. Shouldn't have to touch the bottom end, just freshen up the heads again and take care of the timing chain and water pump. Most likely will reuse the head gaskets and of course the head studs, I don't like TTY anyway. I find on pushrod engines that heads need freshening 2-3 times more often than the short block to maintain power. Best combo for power is a seasoned short block with freshened heads, minimum internal friction and best flow.

 

P.S. My philosophy on accusumps is that if you're depending on them for oil pressure you'll eventually have an engine failure. Keeping the oil pump pick-up covered with oil beats trying to push oil into the engine while it's trying to pump air.

 

Good info. I also think there is a night and day difference in 80's GM tech and 90's Toyota Tech. I think GM may have caught up in the 00's or beyond, but I get your points.

 

To rebuild I would try to keep it simple, but I want it to be reliable and if I can get a little more power then great.

 

BTW- I have put bearings in an engine as I ran it without oil for like 1-2 minutes. They were ok, but replaced the bearings to make sure.

 

I also wonder about true overall cost to get it all done.

 

On the accusump my engine has a fatal design flaw. The oil pick up is all the way to the pass side, like all all the way. I did build a lower oil pan, extented it around, baffled it and lowed the oil pick up. It blew up in 3 laps. They were just not made for G forces at all. I think my engine might be the worst example of this design I have seen.

 

Here in my head is what I would need to do

Parts and labor items

hone cylinder

knife edge crank myself and sand/polish smooth

balance crank

rings

bearings

valve job? I do wonder if this is needed in my engine, but could

port and polish myself

new oil pump and water pump

new timing belt kit

gasket set

 

 

Also,

Can  anyone let me know what the rule is on new pistons when we rebuild? I know oem or similar is fine, but what about higher compression pistons?

Edited by MR2 Biohazard
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9 minutes ago, Team Infiniti said:

We are not talking about 50 yr old American engine tech, do not expect to find many mistakes/casting mismatch/roughness.

Yes, there is not much in when I looked at these engines. Some minor items. That is why I debate doing it as if it would be worth the effort and time.

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Exhaust valves are always leaky  and rough looking on the junkyard Northstar V8's we run so I usually do the heads and time sert the rotten head bolts(all of them are rotten) before we race them but the bottom ends are all TTY bolts and crush fit bearings so we leave them alone,too expensive for parts.

 

Seems I read somewhere that Bill Jenkins said exhaust valve seal doesn't matter,but he was running 8000 rpm down the dragstrip.

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I feel this is personal preference and ability.

My son and I have done both The first race we ran  the motor was untouched and we made the whole race.

Second race we took another motor apart and went through it, bearings, rings, gaskets, valve seals and lapped in the valves.

That motor we dropped a valve late on Sunday, failure was caused by a week valve spring, there will be new springs in our motors from now on.

The first motor we ran that made the whole first race was just beginners luck because I found the timing belt tentioner was froze up and broke.

The belt was replaced 20000 miles earlier had the receipt from the car owner i bought it from.

Failure was inevitable.

I feel if you choose to run a motor with 100000 miles plus and no idea of its history at high RPM for extended time it just a matter of time.

 

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1 hour ago, MR2 Biohazard said:

Good info. I also think there is a night and day difference in 80's GM tech and 90's Toyota Tech. I think GM may have caught up in the 00's or beyond, but I get your points.

 

To rebuild I would try to keep it simple, but I want it to be reliable and if I can get a little more power then great.

 

BTW- I have put bearings in an engine as I ran it without oil for like 1-2 minutes. They were ok, but replaced the bearings to make sure.

 

I also wonder about true overall cost to get it all done.

 

On the accusump my engine has a fatal design flaw. The oil pick up is all the way to the pass side, like all all the way. I did build a lower oil pan, extented it around, baffled it and lowed the oil pick up. It blew up in 3 laps. They were just not made for G forces at all. I think my engine might be the worst example of this design I have seen.

 

Here in my head is what I would need to do

Parts and labor items

hone cylinder

knife edge crank myself and sand/polish smooth

balance crank

rings

bearings

valve job? I do wonder if this is needed in my engine, but could

port and polish myself

new oil pump and water pump

new timing belt kit

gasket set

 

 

Also,

Can  anyone let me know what the rule is on new pistons when we rebuild? I know oem or similar is fine, but what about higher compression pistons?

Without seeing pictures it's hard to say what can be done but you can borrow ideas from other work:

pcmnc2.jpg

116_0709_11_z+440_mopar+external_oil_pum

One relocates the pickup in the pan, the other bypasses it externally.

 

My thoughts:

1. Leave the crank alone, very little gain for the work and expense of rebalancing.

2. Check the second ring; if it is shiny across more than about 50% of the face,  replace them with new rings. A ball hone is adequate for today's low tension rings as the cylinders don't get very much wear. All you're wanting is to provide a de-glazed surface that the rings can seat to. Make sure you follow the instructions.

3. If the bearings look good, put it back together with whatever new bolts you need.

4. Almost every engine will improve with a valve job. Likely the most costly part of the build but that's where the power is.

5. The key to good porting is to blend what's there and resist the temptation to reshape. And yes, there is work to do in every production engine regardless of origin.

6. Fresh parts work better than old parts.

 

With the possibility of a fuel rule and considering that you're already at 10.5:1, I'd stay with the stock pistons for this build.

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2 hours ago, MR2 Biohazard said:

Good info. I also think there is a night and day difference in 80's GM tech and 90's Toyota Tech. I think GM may have caught up in the 00's or beyond, but I get your points.

I look inside a few newer engines (2010+) and there's always something to do. Less low-hanging fruit but still there.

 

My engine is a 2006 G6 LX9, still a pushrod engine but the design uses a lot of stuff that I used to see only in race engines. Think of it as a mini LS. :)

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2 hours ago, MR2 Biohazard said:

Also,

Can  anyone let me know what the rule is on new pistons when we rebuild? I know oem or similar is fine, but what about higher compression pistons?

...  a piston designed for higher compression is not OEM or similar.   So, no.  

.  

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3 hours ago, NigelStu said:

...  a piston designed for higher compression is not OEM or similar.   So, no.  

.  

Time to address that question; I'm willing to bet there are more than a couple engines out there with aftermarket pistons in them.

Edited by mender
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2 minutes ago, mender said:

Time to address that  question; I'm willing to bet there more than a couple engines out there with aftermarket pistons in them.

No doubt.  Seems like an area for a sentence or two to be added to the rule book.  Clarification sort of thing.  I believe the intent has always been for stock internals but it never really says that.    Sort of like how much increase in bore is s legitiment clean up during rebuild?   

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15 minutes ago, mender said:

Time to address that  question; I'm willing to bet there more than a couple engines out there with aftermarket pistons in them.

well not sure how the "foreign" stuff is, but there are stock V8 pistons from 7:1 to 10:1 just depends on the engine use

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5 minutes ago, JDChristianson said:

No doubt.  Seems like an area for a sentence or two to be added to the rule book.  Clarification sort of thing.  I believe the intent has always been for stock internals but it never really says that.    Sort of like how much increase in bore is s legitiment clean up during rebuild?   

 

12 minutes ago, mender said:

Time to address that  question; I'm willing to bet there more than a couple engines out there with aftermarket pistons in them.

 

What are you guys talking about?  Are higher compression pistons a "stock" part?  Do we need to define "stock"?  If they are running but not declared, its pretty clear they aren't following the rules.

 

4.4.1. ALL non-stock components, parts, assemblies, or systems MUST be declared to Tech Inspection,

noted in the vehicle Log Book, and declared and accounted for in the total points of the vehicle.

4.4.2. There is NO SUCH THING as a free part, every part of a vehicle has a value. Parts not

covered elsewhere in the rules will be assigned a point value by ChumpCar Tech.

 

Sorry for my possible ignorance, but do manufacturers not have limits to rebuild specs?  I.e. 1-3 thousandths of an inch over or something like that?

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