Wiseco hd1400 e-85: Wrist pin limit

[kickasskid2087]

Build is below. At what point will the 21mm 6bolt wrist pins hinder performance over a 22mm. Im aiming for around a 10.0-10.5:1 CR on e-85.

The off the shelf 1g Hd1400 e-85 pistons w/ .055 HG thickness end up being 10.25:1.

The 2g Hd1400 e-85 pistons w/ .055 HG thickness end up being 9.4:1.

Turbo flows about 77 lb/min. With room to go down the road if need be. Would it be worth the hit in compression to run a larger wrist pin. Short of a custom piston I will have to sacrifice somewhere.

Thanks.





6bolt-Manley I beam"tuff" rods, Wiesco hd1400 10.5:1 pistons, polished stock crank, acl bearings, Kiggly girdle, arp main studs, L19 head studs, permatorque HG, Curt brown ported head(2g), Ferrea valves, Kiggly valve springs, 3g lifters, dks 272/272, fidanza cam gears, hks timing belt, all oem water pump, oil pump etc. BSEK

E-85, FIC 2150's, Walbro 450 pump, -8 feed, -6 return, custom rail, Jmf race smim, s90 74mm, Tial bov,

Zeta 3.2 billet wheen DBB turbo (62.4 compressor-65 exhaust) w/ 1.00 a/r divided- similar to precision 6265, custom divided t4 manifold, dual tial mvs, side 3" exhaust.

 

[RvlutionMtrsprt]

I would just order 6 bolt pistons and ask them to use 22mm pins. Technically it's custom but it is a very simple request. I have them in the block I'm putting together right now.

 

[kickasskid2087]

Extreme Psi has a packaged deal on piston/rod combo for $1175. Would like to get that deal. Not sure they would be able to get the custom pins.

 

[Steve93Talon]

You can get the HD E85 10.5 pistons with a 21mm or 22mm pin.

 

[kickasskid2087]

Yes but like stated about. The 21mm and 22mm versions are different compression ratios.

 

[99gst_racer]

The off the shelf 1g Hd1400 e-85 pistons w/ .055 HG thickness end up being 10.25:1.

The 2g Hd1400 e-85 pistons w/ .055 HG thickness end up being 9.4:1.

Where'd you get those CR numbers from?

There's not a CR difference between those 1G and 2G pistons. Same dish and compression height. And it's under 10:1 for either.

 

[kickasskid2087]

Straight off of Wiseco's site substituting in a Fel-pro .055 thickness compared to there .042 stated.

http://www.wiseco.com/Catalogs/SportCompact/MiniMitsu.pdf

 

[99gst_racer]

Straight off of Wiseco's site substituting in a Fel-pro .055 thickness compared to there .042 stated.

http://www.wiseco.com/Catalogs/SportCompact/MiniMitsu.pdf

I'm pretty sure that's a typo. I'm almost positive the 6-bolt versions don't have a 1cc dome. I'll find out for sure tomorrow when I get to work.


These e-85 series pistons seem to be plagued with typos and such. They list them being almost a full compression point more than they really are. And when you receive them, the outside of the box says "Mitsu 4G64 w/ 4G63 heads". So it wouldn't surprise me in the least bit to see they also list the dome/dish volume wrong too.

 

[kickasskid2087]

If that is the case is there any options to get at least a 10:1 CR?

 

[99gst_racer]

Force Engineering offers custom spec Wiseco's over 10:1. Hit them up for a quote.


Here's some more discussion on those e85 series pistons: http://www.dsmtuners.com/forums/new...bishi-mls-headgasket-thickness-cr-issues.html

 

[99gst_racer]

Alright, got to the bottom of it. Here goes...

The piston was designed for the EVO engine and so the compression numbers were calculated around the EVO's chamber. When they realized this piston would also work for the 2G DSM, they simply cross-posted the info to the DSM section as well, but someone forgot to take notice to the larger chamber on the DSM, so the advertised compression ratio was always incorrect. Soon after, they introduced a 21mm pin version for the 1G engines using the same specs as the 7-bolt piston. Now fast forward to getting a 2014 catalog ready for print; they finally decided to correct this compression problem. Not only to list it correctly, but also to bump compression up for the 47cc chamber. The 1G piston was recently given a running change from a -4.5cc dish to a +1cc dome. The 2G piston did not follow suit because it would have required a part number change as to no longer interchange between 2G DSM and EVO. For some reason they decided against the 2G DSM having it's own piston and part number, so it will remain a lower compression than the 1G piston of the same series.

And who knows - maybe they'll change this again sometime down the road. I'll be surprised if the compression numbers are right in the new catalog.

 

[kickasskid2087]

So what would the actual compression of the 2 different pistons be?

 

[99gst_racer]

So back to the original question...


With a .020" overbore, a compressed MLS gasket (.051"), and a zero deck, you'd be at 10.4:1 Sink the piston in the hole .015", and you're down to 10:1. This piston sounds like it's perfect for your compression ratio goals. I honestly wouldn't have a single worry about running a 21mm pin with those heavy pin bosses and those heavy wall pins. I say run the hell out of it.

 

[99gst_racer]

So what would the actual compression of the 2 different pistons be?

Given the same varibles, the 2G piston will be ~.8 lower compression than the 1G piston.

 

[kickasskid2087]

The info for the 1g on Wisecos site is correct. 9.4 with thicker HG. and the 2g's would be 8.6 your saying.

 

[99gst_racer]

The info for the 1g on Wisecos site is correct. 9.4 with thicker HG. and the 2g's would be 8.6 your saying.

Yes, the specs regarding dish/dome are correct on their website.

How thick of a HG are you thinking?

Example. For a 0 deck, MLS gasket, .020" overbore:
1G = 10.4:1
2G = 9.5:1

 

[kickasskid2087]

.055 HG. Head decked and .010 bore.

 

[99gst_racer]

Exactly which gasket are you going to use? And what is the overall bore?

 

[kickasskid2087]

Felpro permatorque. And 85.25mm bore. .010 over 6 bolt.

So back to the original question...


With a .020" overbore, a compressed MLS gasket (.051"), and a zero deck, you'd be at 10.4:1 Sink the piston in the hole .015", and you're down to 10:1. This piston sounds like it's perfect for your compression ratio goals. I honestly wouldn't have a single worry about running a 21mm pin with those heavy pin bosses and those heavy wall pins. I say run the hell out of it.

I missed this post completely. Sounds like it would work out fine.

 

[99gst_racer]

Felpro permatorque.

Speaking of more typos; The Felpro MLS gasket is often advertised with a .055" thickness, and it seems many people and websites (Summit, ExtremePSI, etc...) list that to be a compressed thickness. That's a misconception. Felpro does advertise the measurement of .055", but they never advertise compressed thicknesses for their gaskets. .055" is the freestanding thickness, and so the compressed is roughly .051".

And 85.25mm bore. .010 over 6 bolt.

You sure about that? 4G63 overbores are almost always in increments of .020". As is the available shelf-stock pistons too.

 

[kickasskid2087]

Just going off whats information is available. Block doesnt much need a bore just doing it to have a good cylinder to start with. K662M8525AP is the part number. If it is not a typo as well haha.

 

[99gst_racer]

I stand corrected. I guess I never noticed those .010" over part numbers before.

 

[kickasskid2087]

I appreciate the time and help.

Thanks,
Alex