Full cut or laser cut delivery valves.
 

Ok guys, i read on some other forums where people are against them and really hate these. They say you develope a miss that is almost impossible to tune out and they kill your bottom end power to gain some on the top. Along w/ just being to smoky, any opinions on guys running them. This truck will never see the street its a weekend track beater, so it needs to perform well and the smoke is little concern if its annoying ill adj. the afc. Just fuel should equal power if theres enough turbo to go with it and i think i will have that covered. Most say go with the 191's instead of the full cuts, i would apprec. any advise on this, would like to purchase the best for ME the first time around and not have to upgrade later down the road. If it helps some of the other parts in the tune up will be the 4k GSK, edm 435's, either no plate or a ground zero, and a 66/71/13ss. Thanks:cool:

I do not know about the delivery valves but that sounds like it is going to be one cool 81 Chevy race truck.

Adam

What injection pump?

Thanks man, sure working hard to keep the wieght down. I think if she is 4k or lighter it will be fast! My 04.5 rocks and it wieghs 7k+ the way i have it loaded out. Just hoping this 12v works out well, this will be my first. I've worked lots on the 1st gens and all the 24v's, we'll see if i can get this 12v to perform.

Some here what pump?...I did find one thing is the 160 and 175 pumps work good with laser cuts.Been testing a set and finally bought them.In my truck if you push the plate full forward the smoke will increase and power seem to decrease.With the plate in the middle the truck smoked the same as the 131 DV.My power increase alot from low to mid range.Boost went up and EGT stayed the same.

Not 100% sure yet as i Still have no engine. Ive been holding out for weeks to find a 96-98 for the 215 pump. Running out of time though as the trucks basicly finished and ready to fit motor for mounts. So could be any where from 94-98 160-215 pump. Does it make a huge diff. since either way it will have all the same trick parts inside??? Thanks guys .. by the way pm me if you have a lead on a engine for sale

How far are you looking to go with this? You might want to look into a 13mm pump for all out power. This will be my plan in the future. From what I understand, they basically gut the pump, so any pump you send them will work. So look for any engine and run with it. I've got a 175 engine, should work well.

Tate are you saying you have a 175hp engine for sale? Or thats just what you have? If its for sale pm me please. And on the pump ya if money was no issue sure id get a 13 or 14 mm pump for schied for II and be done with it. But the rirst year na, a big single charger and home worked pump with all the goods will have to work. Doing a race conversion like this is not exactly cheap ya know.. so what about the delivery valves, have you heard more good than bad?

you most likely see a decrease in power at full forward because you arn't moving enough air to clear it up. too much fuel without air will put out the flame and you will lose power so the middle position works for you because its a little less fuel with the same amount of air. a bigger turbo will move more air to clear the smoke (or most of it) and make alot more power. something to think about if you are building a race truck and might upgrade turbos down the road, to get more fuel just move the plate.

I hear you on the money aspect. I have a 175hp engine that I'm putting into a 79 ford in the future. Gonna be a race truck, like what you're doing with the chevy. I got a 175 based Dragon Fly from II. We'll see how that works. It was a bit more than your basic rebuild. Hopefully I didn't waste my money. It has upgraded DV's in it they said, I'm gonna pull the number one off and see whats in there. But if you're doing a full race truck, I'd say find any p-pump engine you can and run it. By the time you're done, there will be little of the 175 parts left in it.

Thats prob. good advise thanks. Thats kind of what ive be wondering for a while, is just whats the diff. acualy in the 160 to 215 pumps? If it is all in delivery valves and plate variation then your right get what i can get and those parts will be replaced anyway. Just hope the differances is not more major like cam lift and more mechanical things like that. Thanks

I dont know much about the internals, but there is quite a bit of differance in the pumps. I know my 215 has retard notches so running with no plate will cut fuel back at wide open as this was for starting. The cams are also different between them as is the plunger size. My shop told me that the 94-95 pumps had common cam failures. Either way, you can get sufficiant fuel out of either pump by doing the mods yourself. I think the 94-96 had 11mm plungers and 97-98 had the 12's. I also run full cut dv's and wonder what the diff is between full and lasered. Either way they cut the entire shoulder off the valve. I notice no miss or any running issues with them.

Thanks for the del. valve info. did you notice a big gain in power when going to them? Hows smoke, sounds like you have lots of turbo not sure where it is in size comp. in the 66/71/13ss that i will be running do you? Did you have to go to that much timing because of the full cuts-22* in your sig. You may use yous though for the street to dont know , what plate do you run with those full cuts? Thanks again, Ryan

This is true...

basic of tuning a 12V and having run both, 191 and lasers. I perfer the 191s, a little less heat, and smoke than lasers and still has decent power..Plus i tow... But if smoke is of no concern, then by all means laser it...

Rick

I could totally understand if you run on the street. But this will see 100% track time so you say full cuts all the way huh. Did you really have to make a big change in timming to run them? Can it really make the bottom end laggy. Understand, im after the perf. not the smoke and put on, if the 191's run near as well with lots less issues please let me know. Really no diff. in money just want what will give the best power, also remeber our racing will be mostly 1/8 mile this year. Thanks