Correct FI for 58#1004 with 290HP

[John N.]

Would John or anyone have the expected FI and components for car. Is the 908 distributor correct for the car? When was the latest motor built with the 4960 FI unit?
Thanks

[John D.]

Re: Correct FI for 58#1004 with 290HP

John, The 4800R was used on the early '58 HHP. Probably the '4960 also. Of the two units a '4800R was probably the best of the two since the air meter was reworked. This info came from Gail Parsons. Both the '4960 and '4800-R used the same air meter but the '4800R had a bleed in it to better control the vacuum signal.
But you could probably use either unit and get no static. The 908 is 100% correct for the car. Take care, JD

P.S. I don't have any of the parts needed for your car. I have only worked on a half dozen real '4960's in my life and only owned a couple. Lots of fakes out there though as I know the guy who has made his share of '4960 tags for '4800 units. Can't say who it is though to protect the innocent.

[Tom P.]

Re: Correct FI for 58#1004 with 290HP

John, The 4800R was used on the early '58 HHP. Probably the '4960 also. Of the two units a '4800R was probably the best of the two since the air meter was reworked. This info came from Gail Parsons. Both the '4960 and '4800-R used the same air meter but the '4800R had a bleed in it to better control the vacuum signal.
But you could probably use either unit and get no static. The 908 is 100% correct for the car. Take care, JD

P.S. I don't have any of the parts needed for your car. I have only worked on a half dozen real '4960's in my life and only owned a couple. Lots of fakes out there though as I know the guy who has made his share of '4960 tags for '4800 units. Can't say who it is though to protect the innocent.

John,
The unit that John is inquiring about is for a Nov 57 built car (guess who's building the unit). For this to be as correct as possible for a Nov 57 car (290hp-HD brakes), what should be cast/stamped on the air meter?
I'll be ordering parts for this unit soon---------------after I do a complete inventory of all the parts/unit.
The plenum tag is gone, so I don't know if it is (was) a 4800R or a 4960.

[Jim L.]

Re: Correct FI for 58#1004 with 290HP

The plenum tag is gone, so I don't know if it is (was) a 4800R or a 4960.

Tom,

The only 4800R I've ever seen was a recalibrated 4520 unit. Since 4960s are visually identical to 4800 (non-R) units, it ought to be possible to determine which you have by the presence of the forward hole in the doghouse for the enrichment diaphragm connection (4800R) or its absence (4960).

Jim

[Bill C.]

Re: Correct FI for 58#1004 with 290HP

John,

For what it's worth, page 305 of Noland's book shows VINs as early as 430 and 644 using 4900R units--one of which is an RPO 684 car.

Bill

[John D.]

Re: Correct FI for 58#1004 with 290HP

John,
The unit that John is inquiring about is for a Nov 57 built car (guess who's building the unit). For this to be as correct as possible for a Nov 57 car (290hp-HD brakes), what should be cast/stamped on the air meter?
I'll be ordering parts for this unit soon---------------after I do a complete inventory of all the parts/unit.
The plenum tag is gone, so I don't know if it is (was) a 4800R or a 4960.

Tom etal, Do you have the NCRS pocket spec guide? If not here goes from memory.
A 4800R is an abortion of 57 fuel injection parts. By Abortion I mean the fuel side was built from whatever fuel meter worked good or RP had laying around. Numbers on the fuel bowl would typically be a 7014522 with an 802 stamped over those numbers. Or the number on the fuel meter bowl of a 4800R could be the same as a typical 4800 unit. Stamped just 802.
Now if the unit you have is a '4960 then the stamped number on the bowl ould be a big 962. Now the 962 would have a 4 digit serial number stamped after it. That's typical but not always true. Some of the '4960's just had the number 962 stamped on it.
Now Thomas you said air meter!!! Air meter numbers for '4800, 4800R, and 4960 are all the SAME. 801 or a longer version with the suffix of 7014801 stamped in the air meter.
Do you have Kenny Kaysers wonderful book? "The History of GM's Ramjet Fuel Injection on the Chev V-8"etc etc.???
Turn to page 491. Notice number number stamped on a 4800 air meter. 7014801. Bottom photo. Now to put a wrench into things look at page 490. Notice the 4800 air meter throttle shaft. I know exactly where Ken got this photo. That particular unit is a transition unit. The thottle shaft is not typical of a '4800. Typical of a '4360, some '4960's and all '58 to 62 shafts.
Page 373. The '4960 Fuel Injection. I saw a strange '4960 unit that had a 962 fuel meter but a '4800 ID tag and that it was a bubba unit until I read Ken's book.
By the way if you see a '4960 real deal unit that has a restamped or overstamped fuel meter that says 802 with 962 over top of the 802 it may in fact be an RP factory job. I have seen several '4960's with the overstamp and Ken backs it up.
Can anyone please tell me where th '4800R info is in Ken's book? Does he in fact recognize it as a unit for early '58's or not. I know the '4800 R was an SR unit though.
Read page 422 for late 57 and early 58 FI info.
Those of you that are into FI's must buy this book. It's truly a work of art.
FI Art. JD

[Loren L.]

Re: Correct FI for 58#1004 with 290HP

John, I checked with Don Hill and his 58 #1561 has a 908 and a 4800R - I'm positive about the distributor & 80% sure on the unit.

[Jim L.]

Re: Correct FI for 58#1004 with 290HP

Can anyone please tell me where th '4800R info is in Ken's book? Does he in fact recognize it as a unit for early '58's or not. I know the '4800 R was an SR unit though.

John,

On page 422, the 4800R is acknowledged as having been used in '58.

If there is another mention of it in the book, it's hard to find.

Jim

[Paul B.]

Re: Correct FI for 58#1004 with 290HP

Is there any instance of a 7014800-R unit leaving the factory in a 1957? What about warranty work by Rochester? When units were returned by dealers for service, did Rochester replace earlier models with the improved 7014800-R unit?

[John D.]

Re: Correct FI for 58#1004 with 290HP

Is there any instance of a 7014800-R unit leaving the factory in a 1957? What about warranty work by Rochester? When units were returned by dealers for service, did Rochester replace earlier models with the improved 7014800-R unit?

Paul, I never heard of an instance that a '4800R was used on the line for a '57. Typically it was a service replacement (SR) unit and a good unit at that.
Yes is the answer to your last question.
A friend of mine was the 2nd owner of a '57 FI car. When he bought it the car had a '4800R unit. But it should have had a '4520. The '4800R was a SR unit. Or so we think.
As mentioned Ken's fine book doesn't have a lot in it about the '4800R. I turned a lot of the pages carefully.(I have a hard cover book which is my pride and joy) and couldn't find anything on the '4800R except at the end of the book.
Tip: Be very careful buying a '4800R if you are in the restoration business or have plans on modifying it for your '57. You will get burnt like I did. The '4800R is a great parts unit but for '57's but that's about it. The plenum was typically a '4520 plenum that had the nozzle block holes reamed out for the later style nozzle blocks. Makes a nice door stop. JD

[John D.]

Re: Correct FI for 58#1004 with 290HP

John, I checked with Don Hill and his 58 #1561 has a 908 and a 4800R - I'm positive about the distributor & 80% sure on the unit.

Loren, Don Hill's car was FI setup is 100% correct. That's typically what they used on the early '58's. A '4800 or '4800R and a left over 57 distributor.
Then the next unit was the '4900 with a 906 or a 915 and a '4900 R with a 908 and then a 914 distributor.

Oops. I missed a unit. The '4960 was used also on the early '58's. Sorry. JD

[Tom P.]

Re: Correct FI for 58#1004 with 290HP

Here are pictures of the air meter and three fuel meters that I'm trying to piece together for a unit to go on John's Nov 57 built 58 car.




All three fuel meters are cast 7014312.


One fuel meter appears to be stamped 962 and 1802.


Another fuel meter appears to be stamped 802 3 or 4 times.


The third fuel meter appears to be stamped 802 and 1981.


The plenum has no front hole, thus it wasn't a 4520. It does not have a right side hole for a cranking signal valve, no Winters foundry logo and it has a notch in the center of the left fin. Thus, the plenum would appear to have come from a 4800, 4960 or maybe a 4800R.
What kind of a unit will these pieces make for a Nov built 58? I'm thinking a 4960 unit or a 4800R.

[John N.]

Re: Correct FI for 58#1004 with 290HP

Here are pictures of the air meter and three fuel meters that I'm trying to piece together for a unit to go on John's Nov 57 built 58 car.




All three fuel meters are cast 7014312.


One fuel meter appears to be stamped 962 and 1802.


Another fuel meter appears to be stamped 802 3 or 4 times.


The third fuel meter appears to be stamped 802 and 1981.


The plenum has no front hole, thus it wasn't a 4520. It does not have a right side hole for a cranking signal valve, no Winters foundry logo and it has a notch in the center of the left fin. Thus, the plenum would appear to have come from a 4800, 4960 or maybe a 4800R.
What kind of a unit will these pieces make for a Nov built 58? I'm thinking a 4960 unit or a 4800R.

John
When I bought the car it had a 4900R unit on it(with I believe had a high serial number) and a 914 dist. You had informed me that a 908 dist would
be correct. I recently bought from the second owner (in Hawaii, a young Roland Leong was reported to be a tuner) major parts of a fuel injection unit which Tom now has. His story was that when he bought the car it had two units with it and he put the 4900R on it as that was considered
correct. I thought that portions of this purchased unit might have been
been original to my car and is the reason for the original question. I am trying to determine
(1) What is the correct original unit and components for the car.
(2) Are any of the parts which I purchased correct for the unit.

The 962 802 fuel meter did not come with the unit, but was purchased seperately. It was sent to Tom in case it was determined that it would be correct.

John and everyone thanks!

[John D.]

Re: Correct FI for 58#1004 with 290HP

John & Tom, As far as the nice pics go the 962 casting is not that great and is someone questionable. Although it may well in fact be correct.
4800R and '4960 units are quite similiar. In fact from 3 ft away they may be identical in appearance. On the other hand a lot of the '4800R's used the '4520 plenum. Now that is vague info to you as there were at least 3 of '4520 plenums. The last generation '4520 plenum does NOT have a winters foundry snowflake. The first two do.
Call me Tom so we can figure out this puzzle. Stick with the '4800R as it will fly thru judging with no flags. Use the '908 distributor and you are done.
4800R is a piece of cake for you Tom in that you have some nice castings. The 802 stamped 3 times is no cigar but it is original!!! Sorta reminds me of a '7380 plenum where the worker was trying to stamp the serial number of the 64-65 while the chassis was moving down the line.
Tip: Don't mix up the fuel valves for the '57's if you can help it.

Tom. Use 802 1981 along with the 801 air meter. You didn't post a pic of the serial number of the air meter though. Notice the throttle shaft. Bill Connell showed me one like that. It's for real. Leave it alone. The late '4800-4800R used that shaft. I have seen too many of those units with the 58 to 62 throttle shaft. Kenny agrees with me. Or I agree with him. JD

[John N.]

Re: Correct FI for 58#1004 with 290HP

John
Thanks again for the help! Is the serial number of the air meter the 7014801 that is stamped into the top of the flange area of the air meter in Toms picture?
Regards