Pre-build discussion (7MGTE)

[Doward]

PISTONS:
Currently looking into the Wiseco pistons. I understand they aren't the lightest @ ~327grams - the JEs are ~297g, but I'd like to know if anyone has weighed the stock piston?

The Ross pistons were right around the same weight as the Wiseco pistons.

I'd like to hear back from anyone that has used any of the available forged pistons in their build. $559 including rings is a hell of a deal on the forged Wisecos, and the fact that the top 2 spots on 7Mpower.com use Wisecos, gives them some serious credibility to me

CONNECTING RODS:
I was thinking of re-conning the stockers, ARP rod bolts, and call it a day. With a good tune, these will take a hell of a beating. Bryan's kinda leery about running stock rods @ elevated power output, so I'm going to do some research into this...

CRANKSHAFT:
I've got a '91 Cressida in the upullit - crank's gonna get yanked (should be a 7M crank) and it will be used. Depending on the price of new rods for my motor, I'll either be leaving it stock, or knife-edging it. Either way, everything up above gets zero balanced.

I'm definitely going to line hone the block. Bryan's assuring me that there is no need to stud the bottom end, unless I'm shooting for like 1200+ hp, lol - the bolts are beefy as hell

Boring it will be obvious. The question remains, what size do I bore it - and that will be determined by both the wear I have, and the size of the head gaskets available. I will match the bore of the gasket to the bore of the block, period.

Balancing will be a must. After I go standalone, I will be pushing 7200rpm, and no more, with the 7MGTE. Should I forsee problems with the shims spitting out @ 7200rpm?

I'm considering having Bryan go through the head, and do the oversized valves etc etc to bring the airflow characteristics more inline with the 2JZ head, but ~$1500 cost *may* put it off until the summer - it's not like I can't yank the head out later and send it off Harder to do that on the bottom end, though!

Freeze plugs. Has anyone thought of tapping the holes and using screw in freeze plugs, ala the Ford BOSS series?

This will be a start, and I want to ensure I've done my homework over the next couple days, while I yank the 7M and begin a tear down on her.

 

[TurboStreetCar]

my ross pistons i got included pins and rings and were about the same price from summit, have herd nothing but good about them. just another option.

The bore size i would think would be more deterimned by the piston rather then headgasket, i think theres some room for error on headgasket bore size as they measure that in milimeters and i believe the size options are something like 84mm and 86mm. so with 2mm of diffrence i cant see it having to be perfect for bore size.

What kind of power are you looking for? ive herd the Eagle rods are good when outfitted with stronger ARP studs/bolts. and ive also herd you can score them for about 600bucks.

Should be a nice project, we need more high HP sub 11 second 7m's around.

 

[Gilsdorf]

I've use both the Ross and the Wiseco pistons, I liked the Ross and perfered their "spiro lock" pin retainers better than the Wiseco wire ring (eaiser on the thumbs to install). I also like the Ross pin better, it seemed much lighter compared to the Wiseco pin, just an FYI. I did end up melting the Ross pistons even after I had them Swain Gold top coated (long story, shitty tune, expensive rebuild).

I'm running Pauter rods, I got a package deal on them so the price was a couple hundred more than having the stockers reconditioned (OK, quite a few hundred!). Well worth the piece of mind in my book, I would also use studs in the mains for that exact reason--do I need them for my current HP goals? Probably not. But, knowing that I've got a bulletproof bottom end that can handle almost anything I do in the future . . . Priceless.

Good luck with the build, it looks like you are putting a lot of thought into what you are doing.

Matt

 

[Doward]

Yep, always one to do my homework. I'm going to search for others using Ross pistons, and see their comments on them.

BTW, Gilsdorf, you have the coolest avatar ever.

I can get the Eagle rods for about $440 in a package deal with the Wiseco pistons. I'll look more into the Ross pistons, too!

Keep the comments coming

 

[IJ.]

Ross are good and solid and survived my last "whoops" totally unmarked!

Good idea to look into coating them.

 

[tissimo]

if going to rev higher (7200 like your saying) maybe should consider some upgraded rods..

 

[Doward]

I'm considering Eagle rods right now - I'd be considering the BC rods, but evidently asking the same question 6-7 times over doesn't get a response? I'm displeased thus far in that GB, but that's a different topic :3d_frown:

I need to first find out for sure if the Eagle rods are 5/16" bolts, or 3/8" bolts. If 5/16", that will leave them out of the running for me.

Ian, looks like the Wiseco's have longer skirts... mind if I ask what clearances you run on the Ross, and if you've got any rock or slap from them?

 

[IJ.]

Dow: With the Ross I knocked the specs down a thou but should have gone down 2 as they were a little rattly when cold.

I did this with the new JE's and it's quiet as a mouse when cold.

I run triple coatings and this reduces thermal expansion quite a lot!

 

[Doward]

I think the Wisecos are coated on the skirts at least, from the factory.. definetly will look into them!

Also noticed Flatlander's got a set of re-conned stock I-beams, fully shotpeened + cryo treated. Anyone used them?

 

[IJ.]

Dow: While you may get away with reworked stock rods if you're going to run the motor at 7k+ sustained (not just a blat through the gears time to time) I'd seriously look at good quality rods.

Correct the Wiseco's have skirt coatings but they shouldn't affect expansion at all.

 

[Doward]

What are your thoughts on the Eagle H beams? I've run them in domestics, and other than needing to make sure they were all actually checked over and correctly sized, I've never had a problem strength wise. Eagle's site lists them in the 2007 catalog as 3/8" ARP2000 bolts, and good up to 1500hp. For under $450 in a combo deal with a set of pistons, seems like the way to go!

 

[IJ.]

Never used them but from anything I've read if they're checked for sizing and have the better bolts fitted they're fine.

What's the price difference between those and quality rods ie: Pauters,Carrilo's,Crower's?

 

[Doward]

Approx the difference of me having a knife-edged worked over crankshaft, or a stocker I'm working on a budget (which always sucks) so I'm trying to get the stretch the old dollars as far as I can

Crower's got no ETA on when they'd be done, and the BC rods nobody seems to be able to get me a word on the rod bolt sizes used. If I go with a set of Pauters, that pushes my crank work off (just a stock polish and new bearings, vs a full knife edge, rebalancing, etc) as the $600 difference goes to one or the other. Carrilo's are simply out of my price range I had considered running a set of LS1 rods on custom pistons (6.0" c-c, .927" pin diameter) but the big end width is simply not wide enough - .940"(LS1) vs .975" (7M). The big end diameter of the LS1 rods is 2.1" vs the 7M's 2.166", but that's nothing the machine shop can't take care of

 

[IJ.]

Eagles Good bolts and lightened crank would be nice!

I knocked a bit over 5 lbs out of mine for this build and it makes a huge difference in engine response off boost.

7M Niterided Lightened Crank

 

[Doward]

Oh trust me, Ian - I've seen what you've done, I'm somewhere beyond impressed, and you've done pretty much everything I want to do to my own motor, internally, but couldn't justify just ripping a running motor out.

That's changed now :naughty:

What's wrong with the ARP2000 bolts btw?

 

[IJ.]

Again just from what I've read the 2000's are a bit ordinary and I think it was the L19's were an upgrade?

There was a big thread on them on SF awhile back.

I'd do the upgrade just for the peace of mind as I stated earlier you can't cut corners if it's going to live at 7000+ (I've pulled my limiter back from 8K to 7K)

 

[Doward]

Good point... I'll call IPP in the morning, and see if they can get any different bolts - I'm not seeing anything listed on ARP's web site!

 

[IJ.]

Drop Flub a PM he did all the leg work on this and should be able to point you in the right direction.

 

[Doward]

Appreciate it! So far then:

I'm still considering the pistons to use - either Ross or Wiseco's (not too thrilled the JEs don't include rings, but eh... they're lighter as well, but anything's going to be a good upgrade to stock! Also, the Wisecos are in the two highest hp engines over @ 7MPower.com, so... )

Rods will be Eagles, hopefully with some stronger bolts.

Crank will be pretty much what you have, Ian. Maybe not as pretty - but if you're ok with it, I'll bring that picture to Bryan!

Clevite Bearings (if I can find the real deals) all throughout

Zero balance everything, including the flywheel and.... hey, now there's a thought - Harmonic balancer! 212k miles on the stocker going on? I don't think so!

Gonna have to research that, as well!

 

[IJ.]

Dow: I replaced a brand new stocker (4000KM's) with an ATI for this build dunno what shipping would cost though.

I WOULDN'T run an old stocker at 7000!