7m head on 5m block?

[wiseco7mgt]

What crank were you running 7m or 6m?

[andrew_mx83]

6m. nice and light

soon to be 2m....its a bit rougher in the casting than the 6m and appears to have been ground undersize as all the bearings were stamped 010.

[wiseco7mgt]

Sounds good whats your choice for pistons.? I'm liking my wiseco forgies, no dramas here after 20,000 klms and yes mine gets revved regularly. Sounds like you might need a custom sump if its for raceing the twisties. How about your oil system whats going on there?

[andrew_mx83]

pistons, my next step is to get the 7m-gte block in the driveway, then i can decide on a block to use & get it decked for the MHG. once thats done i will dummy up a long motor so i can get all my deck heights etc etc and cc up the head & original pistons so i can find out what the compression is now. depending what it is i may try and get away with the original pistons for now and plan to do a forged 85mm setup down the track.

due to some changes at home finances are a little tight at the moment so if i dont have to buy expensive bits straight away that would be good, but if i cant get the compression 10:1 or higher on standard pistons with just decking the block/head i will have to do something else. strong aussie dollar is looking good for forged parts out of the states tho


oil system is something i wanna get right, what do they say 80% of engine failures are due to oil starvation? the previous motor always got nasty oil surges on right handers, so the sump will be either baffled or trap doored. will be running a shimmed GTE pump (with the shaft machined down so it doesnt hit the rods) and oil squirters. i have now got an apadtor to semi-remote mount the filter that came with the 5m and it also has the line ready for an oil cooler. if the line sizes are compatible i am considering putting the air con condensor back in and using that as a big fuck off oil cooler and draining back into the sump
will also get an oil TEMP guage as opposed to just pressure as i had before and probably fit a piezo horn to the pressure switch.

[RyleyMA61]

Horn is a great idea! I might do that too.

Is that a bearing from my old engine?! Yikes!

[andrew_mx83]

na thats my old motor, the dead one.

the one you gave me the big end were pretty dead, copper just starting to show but the mains looked almost new.
all the bearings were stamped '93 so must have been rebuilt a while ago lol!


and for a funny coincidence, the bearings in my motor all had the same bday as my daughter!!

[wiseco7mgt]

Love the idea of a trap doored sump, seen a few for v8's but never for a 7m yet, anyone make them?
I use a speco remote oil cooler setup and the oil pressure is great and also makes changing the filter a breeze.(bolted up next to the tow hook under the front) Not sure if i'd like oil squirters for my pistons though, kinda like the maximum flow to the crank i can get.

[amichie]

This may be of some interest

http://www.sipracingmailorder.com/se...per-oil/Detail

[wiseco7mgt]

Heard of a few fitment dramas with the crank scrapers although Rich at SIP is a good guy to deal with.

[amichie]

Heard of a few fitment dramas with the crank scrapers although Rich at SIP is a good guy to deal with.

I bought my 7M Brian crower cams off him and he was very reasonble on shipping costs etc.

[andrew_mx83]

noone makes them that i know of, but i would make it myself anyway i now have a spare sump to experiment with too. not sure if i will go baffles or doors at this stage, doors would be a lot more work.

whats the deal with crank scapers anyway? some people swear by them and others wont go near them.... i was of the understanding that the crank is not sitting in oil anyway (actually i could probably measure this) do they stop oil surge too or just churning of the oil by the crank?

pretty sure the GTE oil pump is higher flow which should make up for the loss of pressure due to squirters. does anyone know if they squirt all the time or just above a certain pressure?


that site has cheap bearings too, i stumbled across it a while ago when pricing up some bits

[wiseco7mgt]

The crank scraper in your application might be beneficial due to the higher sustained revs, the harder you rev, the more drag is created by the oil (increase in rotating mass).
I saw a video once that was a cutaway of a block that showed the oil getting thrown around in side the block under revs, it was amazing .
Just picture riding through a puddle on your bike and seeing the water flicked up behind you then times it by 6000rpm.lol.
The GTE oil pump is the same as the GE oil pump so no it doesn't give you any more flow.
Pretty sure its just the pick up that vary' s.

[Jin~Jah]

The squirters are only supposed to open after a certain pressure, just like the factory oil cooler on GTE's

Over time though, the springs can get tired and they end up squirting earlier than they're supposed to, possibly taking pressure from where it's needed

[andrew_mx83]

cool, i will try and see if they work "properly" while its apart.

i know u can shim the oil pump for more pressure, but with pressure being inverse to flow, is this really a good idea?

looks like i will add the crank scraper to the shopping list....



hoping to have a GTE short block by the end of the weekend

[Supra967]

Can you snap a pic of a 7M-GE piston next to a 5M-E please?