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Can someone give me some input on the 3 FI units used on the 290 HP engine?
The units are the 7017250, 7017300 and 7017320.
Are there any specific inprovements, advantages on the specific units?
Thanks.
Bruce, I can't answer your question but am very interested, I have two 320 units. I think more 320 units were used than the other two (also used in '61). Don H.
Don,
I know that the 320 and the 250 used cranking signal valves and the 300 used a micro switch for cold starting. They both had the same air meters and fuel meters.
I'm just not sure if there was an advantage to the micro switch system or some other advantages or disadvantages.
I wonder if the injectors were different sizes?
JD we need your input.
Can someone give me some input on the 3 FI units used on the 290 HP engine?
The units are the 7017250, 7017300 and 7017320.
Are there any specific inprovements, advantages on the specific units?
Thanks.
Hi Bruce, The 7250 unit was one of the first FI units to use a built in anti-siphon valve in the fuel meter bowl. It was also the first unit to use the so called "good guy" spill valve. 7250's are fairly rare and came out in late 59.
A 7250 fuel meter body is stamped 7017252. Some may be stamped with just the number 252. It was the best unit made from 57 to 59.
The 7017300 FI unit is not one of my favorites. It was made of recalled, left over, etc 57 units. Basically then a 7300 unit is a 57 FI with a different air meter. I always figured that someone buying a new 7300 from Chevy didn't get the best that they had to offer. On the other hand a lot of people like them.
The 7320 unit is 60-61. Very dependable FI unit provided it's updated with the later style spill valve and an add on syphon breaker kit. As far as the advances made in engineering between the 7250 and the 7350 unit I can't think of anything worth mentioning.
Rochester Products did not waste castings.
A 7320 unit is the identical unit as a 7250 except for the plenums. Both had the same air meters and fuel meters. Or did they.
Be suspicous seeing a 7250 unit that does not have a 7017251 air meter and a 7017250 fuel meter. It has a ribbed plenum.
Now in all the 7320 units I have seen they stamped numbers on the castings just use the suffix.
Recap in order of improvements of the 3 units.
7300 is the most primitive.
7250 was the first to have built in anti-siphon valve although you still should have an add on syphon breaker kit to help from bending rods.
7320 was about the same as the 7250 except it has a flat top plenum.
In all the years I have been playing with FI's I have only owned 3 or 4 real deal 7250's. They are tough to find.
You didn't ask Bruce but if you take a 58-59 7014900 or 4900R unit and set it next to a 7250 unit most people wouldn't know the difference as they are almost identical on the outside. Sorry I didn't have the above notes more organized. Suffering from nice flu as didn't get a shot.
John,
That was exactly the info I was looking for.
A friend is looking for a very nice 60 Corvette with either 270HP or 290 HP. I wanted to understand the 3 different FI units before I commented back to him.
BYW, ididn"t get a flue shot, got the flu for 2 days and I now feel great.
Again, thanks.
Bruce B
1960 290 Hp Fi
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