Why would you run a girdle when the engine doesn't need one? You have 7 mains and with upgraded hardware have shown to handle a ton of abuse...
High compression high RPM 7M-GE build
- Thread starter andrew_mx83
- Start date
Yep that was pretty much my conclusion as well. I was gonna use a girdle but the one I have is just a partial girld. Using billet mains and arp hardware is more than enough for my goal of 1k hp.
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No this would be for my customer's turbo build who is shooting for 1000+ rwhp. Girdle is certainly not necessary for my NA build.
Probably not even 100% necessary for the turbo build either, but hey... overkill is the name of the game here
Probably not even 100% necessary for the turbo build either, but hey... overkill is the name of the game here
Still no progress on this one, but ive got a heap of motors/heads to build for customers atm so i made up a new tool for measuring valve clearance
The indicator pointer sits on the lobe, legs grab hold of the bucket and are attached to the indicator body. You zero the indicator, lift the tool/bucket til it bottoms out on the cam, read the numbers and voila - valve clearance measured to a hundredth of a millimetre. Because fuck feeler gauges
Im also building a valve refacer/modifier atm and im wondering if i can maybe use it to somehow make my motor work with the thin HG and not have valves smash pistons... will have a play once ive caught up on work (one day)
The indicator pointer sits on the lobe, legs grab hold of the bucket and are attached to the indicator body. You zero the indicator, lift the tool/bucket til it bottoms out on the cam, read the numbers and voila - valve clearance measured to a hundredth of a millimetre. Because fuck feeler gauges
Im also building a valve refacer/modifier atm and im wondering if i can maybe use it to somehow make my motor work with the thin HG and not have valves smash pistons... will have a play once ive caught up on work (one day)
Your tool is very clever, congrats
For the valve I have no idea, because it can rotate. I think piston modding would be the way here (but I'm by no mean a mechanic to know what I'm speaking about).
For the valve I have no idea, because it can rotate. I think piston modding would be the way here (but I'm by no mean a mechanic to know what I'm speaking about
).
Did you put your head on a flow bench? Posted numbers on 7Ms are far and few between. I would like to see it.
Thanks rollus. Im think of grinding the valve OD down, adding a large chamfer, cutting the valve seats in the head deeper, or a combination of all 3 to get some clearance.
Nick i dont have access to a flowbench unfortunately however i do have plans to build one. I also have almost every casting revision of 7m head here and id be very interested to compare them all. Im currently working on a pair of number 11‘s, good old number 11 complete with core shift -ie the valves are offset to the combustion chamber by around 1mm. Not something i was expecting to see but several #11‘s ive come across are like that.
Nick i dont have access to a flowbench unfortunately however i do have plans to build one. I also have almost every casting revision of 7m head here and id be very interested to compare them all. Im currently working on a pair of number 11‘s, good old number 11 complete with core shift -ie the valves are offset to the combustion chamber by around 1mm. Not something i was expecting to see but several #11‘s ive come across are like that.
I really like that idea of taking some material off the valve/seat to clear the pistons.
I spent 60 hr porting my #2 head with the short divider. This head actually seemed as if it was larger than the tooling needed it to be. There are are large shifts on #1 and #6 ports but there was nearly no shift in the middle #3 and #4 ports. 1mm os valves definitely help give some room to clean up those dips in the valve seats. Many would say the short divider has much better flow and would be best for turbo application but the long divider would have better velocity for N/A. It's just my guess since I have no proof of this. Another theory of mine is the stock valve guides kinda stick out like a sore thumb. The 2JZ Ferrea guides are tapered and seems there is alot to be gained just by spending the $100 on them, lol. Combination of the Ferrea guides and smoothing out the divider it would seem it would cut down on much of the resistance to get around that guide. I was mainly focusing on trying to get as much air volume behind the valve as possible. A few old school v8 guys I talked to said it's really in the valve bowl work that makes the difference. The volume behind the valve is as important as the shape. More volume is more flow since theres just more air available as soon as the valve opens to just flood in. The velocity is good to build pressure behind the valve but thats what a turbo is for!
These are the only real sources I can find that discuss the differences.
http://users.tpg.com.au/users/loats/technical/7mge/portdifferences.html
http://performanceforums.com/forums/showthread.php?67132719-Intake-Port-Characteristics
What I came up with. I never flowed it because mainly I don't really care to get a number figure. I know already it's probably the most I can get out of this head with 1mm os valves. Eventually I may build another head with 2JZ valves, but i'll have to blow this motor up first and I have a feeling it wont happen lol.
I spent 60 hr porting my #2 head with the short divider. This head actually seemed as if it was larger than the tooling needed it to be. There are are large shifts on #1 and #6 ports but there was nearly no shift in the middle #3 and #4 ports. 1mm os valves definitely help give some room to clean up those dips in the valve seats. Many would say the short divider has much better flow and would be best for turbo application but the long divider would have better velocity for N/A. It's just my guess since I have no proof of this. Another theory of mine is the stock valve guides kinda stick out like a sore thumb. The 2JZ Ferrea guides are tapered and seems there is alot to be gained just by spending the $100 on them, lol. Combination of the Ferrea guides and smoothing out the divider it would seem it would cut down on much of the resistance to get around that guide. I was mainly focusing on trying to get as much air volume behind the valve as possible. A few old school v8 guys I talked to said it's really in the valve bowl work that makes the difference. The volume behind the valve is as important as the shape. More volume is more flow since theres just more air available as soon as the valve opens to just flood in. The velocity is good to build pressure behind the valve but thats what a turbo is for!
These are the only real sources I can find that discuss the differences.
http://users.tpg.com.au/users/loats/technical/7mge/portdifferences.html
http://performanceforums.com/forums/showthread.php?67132719-Intake-Port-Characteristics
What I came up with. I never flowed it because mainly I don't really care to get a number figure. I know already it's probably the most I can get out of this head with 1mm os valves. Eventually I may build another head with 2JZ valves, but i'll have to blow this motor up first and I have a feeling it wont happen lol.
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Small update, i put some stock valves in the head and mocked it up with a 1.2mm gasket to check for interference. it all clears (just)
looks like this is the way forward, hopefully i can get more work done on it soon.
looks like this is the way forward, hopefully i can get more work done on it soon.
That sucks but at least this will be running soon from the sounds of it. Which standalone you running?
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Na, im calling that one a win. The head is already ported to suit the OS valves, so i dont think it will flow any less. If anything there is now slightly less restriction at the end of the same size hole. Just means i have to recut the seats and dont have a lot of room for the 60 degree cut which isnt too critical anyway.
Still deciding between keeping my trusty propane carb which has served me well on many 7ms, or going down the injection route with a megasquirt ms3x setup. Liquid propane injection generally makes more power than gasoline but is a minefield of headfucks to setup properly. i might also look at vapor injection setups which are much simpler, but dont get the awsome chargecooling effect of liquid.
I was up til 3:30 this morning on solidworks designing ITBs however so some form of injection ia looking likely
Oh and i had to do a COP setup for a customer recently so i will be running these on my motor either way. I already have a programmable box for spark to go with the carb that should drive these if necessary.
Still deciding between keeping my trusty propane carb which has served me well on many 7ms, or going down the injection route with a megasquirt ms3x setup. Liquid propane injection generally makes more power than gasoline but is a minefield of headfucks to setup properly. i might also look at vapor injection setups which are much simpler, but dont get the awsome chargecooling effect of liquid.
I was up til 3:30 this morning on solidworks designing ITBs however so some form of injection ia looking likely
Oh and i had to do a COP setup for a customer recently so i will be running these on my motor either way. I already have a programmable box for spark to go with the carb that should drive these if necessary.
Nice progress
I would buy with injector bungs, and one of my friends probably too.
Then you would have to machine at least 3 sets
andrew_mx83;2021481 said:I was up til 3:30 this morning on solidworks designing ITBs however so some form of injection ia looking likely
I would buy with injector bungs, and one of my friends probably too.
Then you would have to machine at least 3 sets
I hadnt planned on adding injector bungs, but anything is possible!
How come you want them in the throttles? Before or after the butterfly?
Ps: real men use gantry injection
How come you want them in the throttles? Before or after the butterfly?
Ps: real men use gantry injection
I prefer dual stagged injectors: one after the butterfly, and another one upstream because turbo
(Note, because normally aspired also works)
PS: yes gantry is awsome, but difficult with turbos !
PS: other real men use barrel buttrfly
[video=youtube;1aFd4LtS9LA]https://www.youtube.com/watch?v=1aFd4LtS9LA[/video]
(Note, because normally aspired also works
)PS: yes gantry is awsome, but difficult with turbos !
PS: other real men use barrel buttrfly
[video=youtube;1aFd4LtS9LA]https://www.youtube.com/watch?v=1aFd4LtS9LA[/video]
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OK,
So I'd like this:
With this just before the port side injector:
And we probably want trumpet plenum side for turbo, or no plenum for N/A:
Edit, ho, look what I found:
So I'd like this:
With this just before the port side injector:
And we probably want trumpet plenum side for turbo, or no plenum for N/A:
Edit, ho, look what I found:
Yeah those hasselgren barrel throttles are pretty sweet. I actually came up with a nice design for a slide throttle before i went back to the idea of butterflies.
The current design im working with has the trumpet built into the throttle body rather than a separate piece. There would probably be room to add an injector bung pre-butterfly if needed. Im also running all 6 throttles in a single billet assembly rather than individually for packaging reasons. 6 separate off the shelf throttle bodies take up a LOT of space.
There is a large front flange for attaching an air filter where you could bolt on a plenum for turbo applications, although i hadn't really considered it.
The current design im working with has the trumpet built into the throttle body rather than a separate piece. There would probably be room to add an injector bung pre-butterfly if needed. Im also running all 6 throttles in a single billet assembly rather than individually for packaging reasons. 6 separate off the shelf throttle bodies take up a LOT of space.
There is a large front flange for attaching an air filter where you could bolt on a plenum for turbo applications, although i hadn't really considered it.
From what I read, I think slide throttle is good only at WOT.
Butterfly is good but barrel is even better.
Don't you want to copy hasselgren barrel throttles?
Butterfly is good but barrel is even better.
Don't you want to copy hasselgren barrel throttles?
Lol, no thanks. I dont copy other people's products. If i were to make a barrel throttle it would be my own design.
I think the part-throttle driveability problems associated with slide throttles can be overcome easy enough. In fact with the right profile on the throttle plate i bet you could have a nearly linear relationship between throttle input and airflow (well, theoretical airflow anyway). Certainly closer to linear than a butterfly.
I did a test yesterday of 3d milling a tapered throttle and bellmouth which worked pretty well so hopefully i can go ahead with making the whole lot as 1 big assembly. This way rather than needing manifold, throttles, trumpets and linkages it becomes virtually a bolt-on mod.
I think the part-throttle driveability problems associated with slide throttles can be overcome easy enough. In fact with the right profile on the throttle plate i bet you could have a nearly linear relationship between throttle input and airflow (well, theoretical airflow anyway). Certainly closer to linear than a butterfly.
I did a test yesterday of 3d milling a tapered throttle and bellmouth which worked pretty well so hopefully i can go ahead with making the whole lot as 1 big assembly. This way rather than needing manifold, throttles, trumpets and linkages it becomes virtually a bolt-on mod.