Budget 100x71 Build
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Re: Budget 100x71 Build
You might be able to negate the plug shrouding (if there really is any) by simply running a protruded electrode. I can't even say with any certainty that the plug angle is a hindrance. I'm sure you know of some of the stigmas that have been a crutch for the T4 platform. This might be another.
"It must be the plug angle, because I picked up power when I switched to the 914 head."
"Well were the port diameters the same as the 914 heads that you swapped? How about the valve sizes?" See what I'm getting at?
Here's what I know: at WOT, the 2.0 914 and the 2.0 Bus demanded the same ignition advance to make best power. If the 914 had a much more efficient plug angle, then it would get better results with less timing. My favorite head is the 1.8. It has a better shape to start with. I'd use a 105 bore, and create a big step using the cylinder side walls. Then run the piston out of the bore. Extra meat.
"It must be the plug angle, because I picked up power when I switched to the 914 head."
"Well were the port diameters the same as the 914 heads that you swapped? How about the valve sizes?" See what I'm getting at?
Here's what I know: at WOT, the 2.0 914 and the 2.0 Bus demanded the same ignition advance to make best power. If the 914 had a much more efficient plug angle, then it would get better results with less timing. My favorite head is the 1.8. It has a better shape to start with. I'd use a 105 bore, and create a big step using the cylinder side walls. Then run the piston out of the bore. Extra meat.
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Re: Budget 100x71 Build
Oh! I guess you could hack the end clean off, and drill the rest out...
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Re: Budget 100x71 Build
Yes, good points. I do have access to a good machine shop. But time is not that plentiful so the AA 914 heads seem like the way to go.Clatter wrote: ↑Wed Dec 30, 2020 11:01 amI can answer this one..subtaf wrote: ↑Sat Dec 26, 2020 11:06 pm Love the experimentation and your work with this build.
I'm following along closely as I'd like to build a slightly down tuned version of this with a stroke around ~76mm (can always be talked into more) and peak hp a bit over 6000rpm. Shooting for 180~200hp.
With the infilling required in the chambers do you think starting with a basic 2L AMC head would require much the same amount of work or are the intake ports far smaller?
Keep the posts & photos coming please.
AMC castings don't have the 914 2.0 plug location.
You leave a lot of power on the table if the plug is hidden in the side of the chamber like all the other heads.
Even though you could weld the chambers and old plug hole up, and build a pad for the 914 2.0 plug,
making up a fixture to machine in the new plug location would be a task.
One that is far easier to solve by buying the AA 914 2.0 heads in the first place..
Maybe if you have access to a machine shop and some extra time?
Have you or anyone else on here got any good or bad reviews on the AA 914 head casting itself compared to the AMC casting?
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Re: Budget 100x71 Build
Not really. I just have heard a few times that AA should have improved on the design instead of just copying. I agree.
Re: Budget 100x71 Build
I read a blog post by Ham, in which he detailed a build of a pair of heads using those castings. Bottom line is he said they seemed ok(but time will tell) and thought if there was a flaw, it was that AA adhered too closely to original Porsche casting, where they could have made improvements over the original design.subtaf wrote: ↑Wed Dec 30, 2020 11:16 pmYes, good points. I do have access to a good machine shop. But time is not that plentiful so the AA 914 heads seem like the way to go.Clatter wrote: ↑Wed Dec 30, 2020 11:01 amI can answer this one..subtaf wrote: ↑Sat Dec 26, 2020 11:06 pm Love the experimentation and your work with this build.
I'm following along closely as I'd like to build a slightly down tuned version of this with a stroke around ~76mm (can always be talked into more) and peak hp a bit over 6000rpm. Shooting for 180~200hp.
With the infilling required in the chambers do you think starting with a basic 2L AMC head would require much the same amount of work or are the intake ports far smaller?
Keep the posts & photos coming please.
AMC castings don't have the 914 2.0 plug location.
You leave a lot of power on the table if the plug is hidden in the side of the chamber like all the other heads.
Even though you could weld the chambers and old plug hole up, and build a pad for the 914 2.0 plug,
making up a fixture to machine in the new plug location would be a task.
One that is far easier to solve by buying the AA 914 2.0 heads in the first place..
Maybe if you have access to a machine shop and some extra time?
Have you or anyone else on here got any good or bad reviews on the AA 914 head casting itself compared to the AMC casting?
I think if you were willing to use original 2.0L heads, you'd be fine with the AA copies.
H2OSB
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Re: Budget 100x71 Build
I thought you may be able to use this on later builds . My simple pushrod dis assembly method . I drilled a bit of pine (12mm),then cut it in half and sanded the 2 pieces for a clamp . Then drilled an 9mm hole in a piece of steel flat bar scrap and welded it to the end . 2 pry bars then levered the end out . very simple . Thanks again for sharing the info on the ends etc . My pushrods are 182mm , so I should be able to make up some cheap HD pushrods .
Happy New Year .
Happy New Year .
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No matter where you go , there you are !
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Re: Budget 100x71 Build
Stacks showed up today: designed them with cutouts for the emulsions, radiused edges, 25mm tall. I have an extra set, if anyone is interested...
Last edited by cal 67 on Mon Jan 04, 2021 9:08 pm, edited 1 time in total.
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Re: Budget 100x71 Build
No work done, unfortunately. I had to replace my t/o bearing and clutch this weekend, and had to organize my garage enough to be able to work efficiently. Maybe this week...
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- Posts: 297
- Joined: Wed Apr 08, 2009 5:03 pm
Re: Budget 100x71 Build
Yes, I sketched them up and paid a guy to make a few sets. I have some 50mm tall ones to try on the dyno too:
- Wally
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Re: Budget 100x71 Build
That is smart! I always cut them off way before the end, but that gave up valuable length. This is way better when you need all the length you can get (tell about that one )!wreck wrote: ↑Thu Dec 31, 2020 5:18 pm I thought you may be able to use this on later builds . My simple pushrod dis assembly method . I drilled a bit of pine (12mm),then cut it in half and sanded the 2 pieces for a clamp . Then drilled an 9mm hole in a piece of steel flat bar scrap and welded it to the end . 2 pry bars then levered the end out . very simple . Thanks again for sharing the info on the ends etc . My pushrods are 182mm , so I should be able to make up some cheap HD pushrods .
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- Joined: Wed Apr 08, 2009 5:03 pm
Re: Budget 100x71 Build
Been busy reorganizing. I have a few projects, and I'm trying to get things to flow a bit bit better in my small workspace. I'll get the case on the stand tomorrow. I saw that my Q cam was ground, but it's not Parkerized yet. Maybe Monday...
Got my LS groove valves: I'll cut the 48s down to 44. They're pretty nice for $9 valves.
Got my LS groove valves: I'll cut the 48s down to 44. They're pretty nice for $9 valves.
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Re: Budget 100x71 Build
Love those 3D printed stacks.
Nice job.
Nice job.