Machine deck with shortblock assembled?

[CyFi6]

Ive recently been considering all my options for my 7mgte that i want to put in my supra. Right now i have a block, rods, crank, all the parts etc. These are the operations that need to be done:

- Crank ground
- Undersized bearings
- Block main webbing line bored and matched to the crank and bearings
- Rods re sized to match crank/bearings
- Small end pin bushings inspected/possibly replaced
- Cylinders bored/hones .020" over
- .020" over pistons and rings (~$120)
- Suspect that valve guides need to be replaced and re sized
- Head gasket surfaces milled to proper RA
- MHG

Now with all these things considered im picturing all the machine work alone being well over $1000 done properly.


This is just going for a stock short block rebuild, and the costs are very high if my estimate is accurate, for a stock built bottom end.

My other option is to go through a service such as this
http://www.rpmrons.com/Toyengines1.html

Where the fully built short block is only slightly above $1000. My only concern with this route is the deck surface, it doesn't seem logical to buy this thing all assembled and have to tear it all back apart again just to get the deck surfaced to the proper RA.

What im wondering is can i take this fully assembled short block to get the deck machined to the proper RA for a MHG and have it cleaned out properly without taking it apart? At this point it doesn't seem logical to build my own engine with all the machine work that is involved, when i can just go out and buy a fully rebuilt unit.

Thanks for any suggestions.

I also must add, this build is going for a little over stock horsepower at first, im not shooting for big numbers. Im going for reliability here, i want a car that is quick around town while maintaining perfect reliability.

 

[Rennat]

Why the line hone? i remember that costing a pretty penny and isnt needed i was told if your using stock fastners...

but i dont see how you'd get every metal shaving out with the block having pistons, rods, and a crank in, ect...

 

[Clip]

i would definitely feel more at ease stripping the block bare to get any machine work done to it.

 

[rtrdpenguin]

Definitely strip it.

 

[CyFi6]

Well seeing as Toyota uses different tolerances on each main web, if im using non Toyota bearings it must be line bored/honed to get them all to the same size.

 

[suprarich]

The main journal bearing housing holes are all the same size from the factory.

Yes, a block MAY need line bored even if using stock fasteners. (just had to do one)

Assembled block could be hand lapped, but it would need to be a bare block to be milled. A block should be tank washed after milling to remove all the metal shavings. On top of that, it would be a major PITA to mount an assembled block to the bed of the mill. I would not even try that if someone asked me to.

Rods get sized back to standard, not to match an undersize bearing. The crank size is adjusted to make clearance, not the rod.

 

[CyFi6]

I thought there was no "standard" for main and rods? Considering there is a numbering system for the rods mains and crank? I guess i am mistaken.

 

[suprarich]

Toyota used a "select a size" bearing system on the rods, not the main caps. When you resize the rods for non-toyota bearings, they are resized to one "std" size to fit the bearing as specified by the manufacturer of the bearing. The manufacturer will specify the std size that the bearing housing hole should be. Under size bearings are still just as big in diameter as a std size bearing, they are just thicker. Yes, Toyota does not really have a standard for rod size, but the difference between the numbered sizes is very very little. All aftermarket bearing manufacturers have a standard for the rods.

I like to grind the number off the cap after resizing the rods so that the next guy is forced to mic the rods and not assume they are still toyota sizes.

 

[CyFi6]

http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=EM&P=72

Im confused. It looks like they use select fit bearings on the mains also.. I have in front of me a Taiho/Toyota main bearing shell that has the number "2" stamped on it in ink.

 

[CyFi6]

Bump, still confused on this. Basically i want to know how to PROPERLY rebuild a bottom end when grinding the crank is required... What all must be done?

 

[92TealSupra]

Bump, still confused on this. Basically i want to know how to PROPERLY rebuild a bottom end when grinding the crank is required... What all must be done?

Alright. Since you may not know a ton about engines and how things are properly done I will give you a slight walk through.

All the stuff you want basically means YOU, or the machine shop will be disassembling your motor. From there they can inspect all parts that they will be reusing, and make sure they're not worn or starting to give way. Having things in spec keeps motor running longer. :icon_razz

The crank will come out. You may not feel great about it, but I have yet to see many machine shops ever keep things together.

Beleive it or not they know what they're doing, most of the time.

If I were you I would find a shop that understands this motor. I would also advise you to find more about your motor and read as much possible. When you decide to bring it in they may go off of your direction, if you mislead them, you will surely end up with a mess.

I hope this helps you. I am not huge on engines quite yet and I myself am still learning. I do not feel like walking through the processes of what you need right now because you have not asked fro that.

Good luck.

 

[CyFi6]

Im not interested in how to rebuild an engine 101. Im interested in what THIS engine and many other Toyota engines need for a PROPER rebuild. And no, that doesn't mean taking out Toyota bearings and putting in STD size clevites. What i don't understand is what needs to all be machined. Are the main bores all the exact same size from the factory? Are the rod bores all the exact same size from the factory? Are the crank journals the only things that require the select fit bearings? What are the select fit bearings compensating for exactly (Main bores, rod bores, crank size, all?)? Thats what i don't completely understand, and no amount of reading is helping me because according to all my research most people building these motors are doing it WRONG.

 

[suprarich]

Call me at 330-541-1122 9am to 5 pm weekdays and I will be happy to explain everything in great lenght, just don't feel like typing out a book here on line. And you are 100000% correct when you say most people are doing it wrong.

 

[Nick M]

No really? Is that why there are threads about a 7M do-over 4 or 5 times from some people?

No engine piece is identical unless it has been blueprinted.

Cy, you are doing fine by trying to get the right answers. If only others would do the same. Give Rich a call. IJ is loooong distance.

 

[Jeff Lange]

Toyota used a "select a size" bearing system on the rods, not the main caps.

No, Toyota uses select fit for both.

The Block Main Journal Bore had 3 sizes from the factory:

1 = 64.024 - 64.030 mm
2 = 64.031 - 64.036 mm
3 = 64.037 - 64.042 mm

The Crank Main Journal Diameter also had 3 sizes from the factory:

0 = 60.007 - 60.012 mm
1 = 60.001 - 60.006 mm
2 = 59.994 - 60.000 mm

Toyota has 5 standard-sized select-fit bearing sizes available for the 7M to accommodate these variations:

1 = 1.988 - 1.991 mm
2 = 1.992 - 1.994 mm
3 = 1.995 - 1.997 mm
4 = 1.998 - 2.000 mm
5 = 2.001 - 2.003 mm

Jeff

 

[92TealSupra]

No, Toyota uses select fit for both.

The Block Main Journal Bore had 3 sizes from the factory:

1 = 64.024 - 64.030 mm
2 = 64.031 - 64.036 mm
3 = 64.037 - 64.042 mm

The Crank Main Journal Diameter also had 3 sizes from the factory:

0 = 60.007 - 60.012 mm
1 = 60.001 - 60.006 mm
2 = 59.994 - 60.000 mm

Toyota has 5 standard-sized select-fit bearing sizes available for the 7M to accommodate these variations:

1 = 1.988 - 1.991 mm
2 = 1.992 - 1.994 mm
3 = 1.995 - 1.997 mm
4 = 1.998 - 2.000 mm
5 = 2.001 - 2.003 mm

Jeff

That is great to know I was just looking up the specs myself on OnDemand5.com

I just wanted to let anyone know if they need Torque specs, how to put things together, clearance spec's, or anything I have a membership to one of the best sites available.

I can't give out the password, and user name, but if you need anything looked at, let me know I can find any make and model in the USA, not Lambo's or or anything of that sort.

-Teal

 

[suprarich]

That is very good info there Jeff. No book I have here for bearing sizes ever mentioned different sizes for the mains. I am very surpized to hear about the bearing housing hole for the mains. I have never seen a block with markings on the main caps to indicate sizing like they did with the rods. Also the last 10 blocks I have worked on all had the bearing housing holes with in .0002 spec. Either I was lucky, or someone had aline bored them before. Did they do this with every block of every year? I know at least 5 blocks that I have done that have never been touched before that had all one size bearings on the mains and the housing holes were one size.

Thanks for posting that list, I printed it out to keep in my book!

 

[Doward]

Bryan Maloof mentioned Toyota using slightly different bearings in the saddles, and we measured this out and found it to be true.

So I had him do a full align hone on the bottom end for the Clevite P-series I tracked down

 

[Jeff Lange]

That is very good info there Jeff. No book I have here for bearing sizes ever mentioned different sizes for the mains. I am very surpized to hear about the bearing housing hole for the mains. I have never seen a block with markings on the main caps to indicate sizing like they did with the rods. Also the last 10 blocks I have worked on all had the bearing housing holes with in .0002 spec. Either I was lucky, or someone had aline bored them before. Did they do this with every block of every year? I know at least 5 blocks that I have done that have never been touched before that had all one size bearings on the mains and the housing holes were one size.

Thanks for posting that list, I printed it out to keep in my book!

The marks are not on the caps, but rather on the block, see pic in IJ's post.

I've seen quite a few blocks with different sized main bearings.

Guess you've been lucky!

Not that it matters that much if you're building a block, since everything should be checked anyways.

Jeff

 

[IJ.]

It's stamped in the pan rail.

[thumb]http://ij.supramania.com/assembly00.jpg[/thumb]