Ah I was wonder how to get it to move to test this, thanks.
The Official 1HD-T/FT Fuel Pump Mod Tuning Thread (3 Viewers)
- Thread starter ForealBoreal
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Without the spring in place the rollers should ride the ramps on the cam plate as you turn the engine and send the piston out
I'm still trying to figure out how that servo thing sitting inside the timing piston actually works. I can move it freely in/out about 10mm as it is able to move independently of the main timing piston. But both springs sit on the face of it so it's a tad confusing how it all functions during operation. I've just done some small road testing and it seems the adjuster on the end cap which preloads the inner spring has a massive effect on light load timing but can't notice any change in full load timing. There's about a 1mm window where the engine will rattle its head off driving along under light load conditions vs being completely silent which is very interesting. It doesn't seem to have any effect on full load timing or timing at max rpm which I think is where the shim on the larger outer spring will affect these areas. Looking forward to carrying out more testing and to learning more about this system.
I'm not interested in a fuel pin as I make my own from blank pins to suit my needs but i'm sure others might be interested. I saw a post the other day from someone on here asking for companies that supply modified pins so might be something to look into.
So glad I got this spacer kit, my car has never driven so well! I can now have my cake and eat it too. Previously I had to compromise with my static timing having to choose either having great early rpm performance and have power die off after 3500rpm or set it to have great power all the way till redline but not so great down low. Now with this spacer I can set the timing for the awesome low rpm performance and with the extra travel in the piston still have power at redline. Very happy man
So glad I got this spacer kit, my car has never driven so well! I can now have my cake and eat it too. Previously I had to compromise with my static timing having to choose either having great early rpm performance and have power die off after 3500rpm or set it to have great power all the way till redline but not so great down low. Now with this spacer I can set the timing for the awesome low rpm performance and with the extra travel in the piston still have power at redline. Very happy man
Glad its working as well for you as it does for those of us with Land Rover TDi and Cummins engines
Did you drill the shim to fit in the end? Any adjustments to your pre-load screw?
Also for those not so well versed on Toyota engines and 4wd models, what engine and 4wd have you installed it in?
No I didn't end up drilling the shim and using it as I was very happy with how it went with only preload adjuster changes. Did some testing with different pe-load adjuster settings and I've found I got best results after increasing this by 4.5mm from the original position.
I have a 80 series HZJ80 which I've converted to a 1HD-FT.
Thanks for the feedback, do you know the overall height of the screw?
Glad it's working well though!
Any updates or more info on the shim for timing advance at higher rpms?
Would be good to hear more feedback from @KiwiDingo now he's had it installed a week or so?
This is my product he's installed which I sell for Bosch VE pumps.
Dynamic Timing Advance Spacer Kit | Steg's Supplies
Tuning part for Bosch VE injection pump.
stegs4x4.co.uk
@hdjtrent80 @NRS91 I'm really not sure what else to say other than what I already have. The spacer kit performs exactly as it's intended by given more travel in the timing advance piston. It's allowed me to reduce my static timing to get the awesome low rpm performance I had to previously compromise on as I preferred it set for the high rpm area but now with the extra piston travel I can have optimum performance in both areas.
Most people would be the opposite to me though as most have their static timing set for low rpm performance and compromise the high rpm. So with this spacer they won't notice any change down low but their high rpm performance will change for the better with the extra timing they'll be getting extending the point at which the power continues to increase where it would normally drop off requiring you to pull another gear to keep accelerating at the same rate
Most people would be the opposite to me though as most have their static timing set for low rpm performance and compromise the high rpm. So with this spacer they won't notice any change down low but their high rpm performance will change for the better with the extra timing they'll be getting extending the point at which the power continues to increase where it would normally drop off requiring you to pull another gear to keep accelerating at the same rate
@KiwiDingo Blank fuel pins, where I can buy them?
No idea anymore sorry, the company I used to get blank ones from no longer is in business.
May I ask you to post pics of your pin? Or may be you have drawings?
Servo and standard advance achieve the same result but go about it in different ways. The servo piston still directs transfer pressure to the power side of the advance piston. It was designed to be more stable than standard advance. Light load is adjusted on your governor shaft. Yes changing your spring tension on your advance piston would change the point where light load starts to come in but normally light load would be adjusted after your finished setting speed advance.
Does anyone know what the 12mm VE pump and injectors has as far as a maximum value for Lb/Hr in flow capability when it comes to setting this pump on a bench for much higher boost and fuel requirements with a larger turbo?
Meaning is it capable of 100,150, maybe even 200lb/hr if being modified for performance buy an injection shop? Just trying to see if anyone has seen or come across any of these values.
Meaning is it capable of 100,150, maybe even 200lb/hr if being modified for performance buy an injection shop? Just trying to see if anyone has seen or come across any of these values.
Would it be possible to have this tested on a bench? Meaning if we installed this spacer that you have had great success with would we be able to see at what rpm the pump is at vs how much it is advancing over the rpm range?
On the Bosch VE pumps there is a special tool which bolts in place of the end cap so the Pump shop can see how far the piston has moved for a set case pressure/RPM, I guess there would also be a Zexel and Denso equivalent if the Bosch one didnt work?
Yes, it's done by all shops when calibrating the pump.
So what about flow? Is there a limit we can flow this pump and injectors too? That is known I suppose. I’m trying to use Math as best I can to size a specific turbo and need to know the limits of a fuel pump modified or even not.
Never really bother to look too much into the max flow as I'm not pushing for very high HP. I've commonly heard figures as high as 160cc from local pump builders for their performance VE pumps so I guess it may be possible to get higher although I'm also guessing you'd be starting to sacrifice internal case pressure and timing control when pushing them too high.
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