340 and 150 shot

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Sully_PA

Sully_PA

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Can a rebuilt 69' x head 340 with a little hotter cam than stock handle a 150 shot of nitrous ok ?
 
It will handle more than that. Just make sure you have good fuel delivery and retard the timing a few degrees.
 
Roger that.....I've been doing a lot of reading lately on it and wanted to get back here and see what you guys thought...lot's of conflicting info out there ....
 
moper said:
It will handle more than that. Just make sure you have good fuel delivery and retard the timing a few degrees.
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Agree, electric fuel pump is a must along with a fuel pressure gauge to set your pressure.
 
Nitrous express:

"any V8 will take a 150 shot"

"after that it's whatever the weakest link in your engine is"

I was told 250 shot on my 440 and that the block was the weak link.
 
In regards to the fuel system. Check out the S.A.F.E. system by nitrous express. It's a very small fuel cell with it's own fuel pump that goes in your trunk. Fill it with race fuel.
 
I have ran 4 or 5 bottles through my 340, 100-150-200, just be sure your tune up right. I pulled a few more degrees of timing than needed at first to be safe.
 
Great tips ...thanks ....when I'm closer to install I'll revisit this!
 
Not sure assuming whatever came stock ....may be able to find out though ...
 
gtsdude said:
I have ran 4 or 5 bottles through my 340, 100-150-200, just be sure your tune up right. I pulled a few more degrees of timing than needed at first to be safe.
Click to expand...

Smart. Always play it on the safe side and then read the plugs. Race fuel will allow you to pull less timing and not go as far on the plug drop.
 
I ran an N20 cheater kit on my stock block 10.5:1 340 for yrs, way back in the 80's, from 125>250hp, never ever tipped a plug, 1 step colder, or had any misfires or anything, and only came back on the timing for the 250 shot a couple of degrees, we ran 98 oct fuel (4 star as it was called here). Ignition was MSD6A....went from 12.4 n/a > 11.01 w/250 shot, 6psi.

The 250hp shot then used 110/110 jets which I believe was well safe, I think the petrol jet is smaller on todays equivalent kits?. Therefore I would say it is even more important to run a dedicated pump and around a 1/2" line for N20 fuel alone for continued use especially with shots over 150hp, perhaps thats overkill, but thats how I had it set up and had no issues, (2 Blue pumps), ran same set up on the 440 6-pk bottom end car I ran as well, went down to 4psi as well a few times and went a touch quicker. Just some experiences from back in the day..........

340 was with a DC .590 solid cam, 440 was with a CC .650" solid
 
What spark plug did you guys use for your 340's with the spray? Do you have to use a special plug? Im running NGK GR4's right now, just a 150-175 hp kit at the most
 
Try it in 3rd gear ,then second to third,and then......Make sure U joint ,drive shaft good.Have fun:happy1:
 
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