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BrianC72gt (Forum Supporter)
BrianC72gt (Forum Supporter) Reader
4/28/22 5:36 p.m.

Bike Carbs, not bike injection, yes?  I had a sidedraft Webber on an MGB 18B motor and really wished I had an independent vacuum source.  Next time you are in the Pick-n-Pull, grab one off of a Volvo.  I think it may be a Ford part.  Either way, it is compact and cheap, and will keep the brake booster happy.    Do you plan on a distributor or crank trigger for ignition?    The distributor relies on a strong vacuum signal for the vacuum advance, not sure if twin webber manifolds will get you there.  I had to play around with springs and weights on the stock dizzy, then went with a full mechanical dual points mallory.  But nowadays, maybe a couple of sensors, a crank trigger and megasquirt?

 

twentyover
twentyover Dork
4/29/22 11:08 a.m.
BrianC72gt (Forum Supporter) said:

Bike Carbs, not bike injection, yes?  I had a sidedraft Webber on an MGB 18B motor and really wished I had an independent vacuum source.  Next time you are in the Pick-n-Pull, grab one off of a Volvo.  I think it may be a Ford part.  Either way, it is compact and cheap, and will keep the brake booster happy.    Do you plan on a distributor or crank trigger for ignition?    The distributor relies on a strong vacuum signal for the vacuum advance, not sure if twin webber manifolds will get you there.  I had to play around with springs and weights on the stock dizzy, then went with a full mechanical dual points mallory.  But nowadays, maybe a couple of sensors, a crank trigger and megasquirt?

 

I had OldSkewelToyota (the guy doing the head porting) port matched a set of DCOE manifolds, but my heart is not in webers. Yielded to the siren song of Bike Carbs. I bought a set of RX-1 sled carbs (same basic motor as a Yamaha R1, adapted for sled use.) Just opened the box O' carbs a couple days ago

 

Need to rebuild them (got the choke slide working again, but the throttle blades are frozen (see what I did there? Sled carbs- frozen? Well, if I gotta explain it , it losses funny fast) time for a nice warm bath in PB Blaster or mix up some axetone and ATF. Hmmm. Axetone? Maybe a new trademark for the acetone/ATF mixture?

 

Two potential solutions for braking- electric power assist or my preferred solution- press the pedal harder.

 

Thinking I may go with crank trigger, maybe integrate the TPS to manage load sensing.

 

Planning on breaking the carb rack apart and spacing the carbs for direct shot at the port.

 

So why hasn't GRM ever investigated Bike Carbs? Gaunlet has been thrown down

twentyover
twentyover Dork
11/14/22 12:40 p.m.

As we gather around the Thanksgiving table, we go around and tell each other what we're thankful for. When it comes to me, thankful the short block is back from the machinist. 

OK, truth is I picked it up in early October, took it back home to WA, put it in the barn on a moving cart, and left for California again. Sister-in-law is dying from Cancer (easier to list the places it hasn't mestastisized to than where it has.) Since I'm the one in the family not working, I get to be her daily care giver.  Ben a bad couple years for my wife- Mother passed April last year, Dad passed last February, and now this. We determined SIL was ill while traveling  to Illinois to bury FIL   

Since the snow has fallen (my brother reports I have a bout a foot at the house), I'll be heading back to WA about the 3rd of December or so. I'll need to find an incandescent bulb to drop into a cylinder overnight to bring the block up to above freezing to get paint on the block before I put it away for winter and head back to SoCal

MyMiatas
MyMiatas Reader
11/14/22 10:50 p.m.

 I read your thread and a question came to mind on your cylinder head rebuild...Wouldn't stainless steel valve seats been a good choice? I was surprised that I did not notice them in the pictures. Looked like a great job on the port polishing. A lot of time spent with a pencil grinder.

twentyover
twentyover Dork
11/16/22 7:59 a.m.
MyMiatas said:

 I read your thread and a question came to mind on your cylinder head rebuild...Wouldn't stainless steel valve seats been a good choice? I was surprised that I did not notice them in the pictures. Looked like a great job on the port polishing. A lot of time spent with a pencil grinder.

All credit for the head work goes to Oldskewltoy. His experience with Toyota aluminum heads has me at ease with his choices.

I see the joint where a hardened seat was installed in the head, but will take a look when I get back early next month

oldeskewltoy
oldeskewltoy UberDork
11/17/22 12:56 p.m.
MyMiatas said:

 I read your thread and a question came to mind on your cylinder head rebuild...Wouldn't stainless steel valve seats been a good choice? I was surprised that I did not notice them in the pictures. Looked like a great job on the port polishing. A lot of time spent with a pencil grinder.

For the valves chosen(+1mm - aka "Stage 2"), the original seats were still more than adequate - new seats would have run "twentyover" more $, and we had decided early on to keep the valve sizes limited to +1mm oversize.   

 

22RE valves could've been used - they would have required larger seats.   

What I wrote to "twentyover",

"From my reading you can run the even larger 22RE valves(as long as we replace the seats), but they are different length valves, and may cause some operational/interference issues with the higher lift cams.  I'd recommend running the 1mm oversize (upgraded valves listed) and not worry about the 22RE valve sizes."

twentyover
twentyover Dork
11/17/22 5:27 p.m.

I had also advised Oldskewltoy I was looking for a meatier midrange, and was willing to sacrifice ultimate top end for a fat middle. This drove several of our choices,

And it may change latter, or I may break out the OTHER 20R in the barn for Stage "morenthan 2"

03Panther
03Panther PowerDork
11/17/22 8:37 p.m.

I actually managed to "break" two different 22r engines, back in early '90s! One through deferred maint. (Read neglect) on my part. And then it's replacement - a bone stock 94 that a friend threw a 480 lift / 280 duration cam in! It ran.. interesting. Till the guides wore, a bit of broken guide made it jump time, and bent the valves. 
Only thing I remember about the difference in the 20r and the 22r, is folks the built them liked a 22r bottom end, with a 20t head. Don't remember why. 

GillesDecourse
GillesDecourse New Reader
11/17/22 11:39 p.m.

Sucks to hear about all the bad things happening around you lately, hope this engine build helps with moral, it's been great to read the progress about this tractor engine as I will be rebuilding mine soon too. Here is a photo of my 20/22r hybrid on zx9r carbs (keihin cvk 40) . 0,5mm oversize SS valves, stock cam and bottom end with a bit of head work too. It's been running great for 3 years now, no problem with brake booster or distributor vacuum with a simple pod, I get good gas mileage and drivability with minor work done on the carb tune. If you have any questions let me know I'll be glad to help.  I'll be rebuilding soon too, I have a crane/trd cam and forged pistons already as parts and will be ordering more soon  Which valve springs did you choose?

 

 

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