fuel injection gaskets

[Frank D.]

Re: fuel injection gaskets

I agree with keeping the gases away from the adapter plate for the reasons stated (heat and corrosion). I use the block off for both of my FI cars. Keep in mind GM never planned or cared about 50+ years of use. JMHO, Don H.

Or modern gas; I've used the vendor 'blocked off' gaskets on my '61 270hp car to help with percolation. However, it changes the sound of the engine (harmonics) I guess so it sounds like two Harleys chasing each other down the street. So, I added a crossover pipe in front of the oil pan to even out the exhaust tone.

[Stuart F.]

Re: fuel injection gaskets

Sounds familiar (no PUN intended).

Stu Fox

[Alan D.]

Re: fuel injection gaskets

Well here's a little help however do not have access to an early intake, but at least these are the dimensions
The only gaskets (GM) I have are pn 3772384

[John D.]

Re: fuel injection gaskets

Joe Lucia and others. The reason why the 3770284 Fuel Injection adapter plate gasket set was unique to Fuel Injection cars is because the kit contained two special gaskets for the FI distributor spacer pin. One notched gasket goes on each side of the pin of the spacer. The spacer goes into a small hole where the distributor mounts.
Other than that the gaskets were the same as other engines. (except no metal plate).
Above info supplied by Michael Hanson. Which is was back on the DB as he forgot more than most of us know. John D.

[Joe L.]

Re: fuel injection gaskets

Well here's a little help however do not have access to an early intake, but at least these are the dimensions
The only gaskets (GM) I have are pn 3772384

Alan-------


Are you saying that you have a GM #3772384 gasket set? If so, I'd like to see a photo of the side gaskets as well as the dimension of one of the port openings (i.e. side-to-side and top-to-bottom).

[Bob J.]

Re: fuel injection gaskets

Stu-------


Yes, the gaskets you described were used for some truck applications.
However, the same type gaskets came back and were used for some passenger car applications in the mid-to-late 70's.

Anybody have a GM part number on these ?

[John D.]

Re: fuel injection gaskets

Some of you say keeping hear away from the aluminum. Well that particular port never seems to have any indication that it' has any issues.
On the FI baseplates the problems I see are the two end ports. Especially the rear for some reason. I see lots of 'them were they eaten up very bad. THe front port also. Period.
Well we spent a lot of time on this and it was fun... But old JD is off to work. Hope you are staying cool. JD

[Joe L.]

Re: fuel injection gaskets

Anybody have a GM part number on these ?[/COLOR]

Bob-------



GM #356801 and, later, GM #10174954. There may have been others.

[Bob J.]

Re: fuel injection gaskets

386801 is for a 75 with AN EGR?
Nice, it will be very attractive on an early FI Corvette.

[Joe L.]

Re: fuel injection gaskets

386801 is for a 75 with AN EGR?
Nice, it will be very attractive on an early FI Corvette.

Bob------

All 1973 Corvette with 350, all 1975 Corvette, and 1976 Corvette with California emissions. However, I believe these gasket sets only have the metal plate with a round hole on one side. The other side is open. Aftermarket replacements usually come with 2 plates to install in one or both sides. Some applications, although not Corvette, use the plates with holes on both sides.

Keep in mind that the 356801 and 10174954 gasket sets include the 1969+ style end seals and these seals cannot be used on 1968 and older.

By the way, all Corvettes from 1973 and later were equipped with EGR.

[Bob J.]

Re: fuel injection gaskets

Joe
Yes, I know on the EGR useage.
That gasket set you mention (356801) is not anything like an early truck gasket set. It's not related to this thread or discussion
The 356801 has one side gasket open with NO blocking plate, the other side gasket has a plate has a big hole in it....nothing is BLOCKED OFF.

I still do not remember any blocked off gaskets (SBC) sold by Chevy for anything but trucks.

John, sorry your thread has run off the tracks with talks on late model unrelated gaskets----I'll no longer ruin your nice thread.

[Joe R.]

Re: fuel injection gaskets

John,

Thanks for your suggestions and input! You have more experience with FI than all the other members combined in the NCRS so it would be wise of the members to take note of your suggestions.
And thanks to Bob J. and Michael Hanson for their input.

JR

[Joe L.]

Re: fuel injection gaskets

Joe
Yes, I know on the EGR useage.
That gasket set you mention (356801) is not anything like an early truck gasket set. It's not related to this thread or discussion
The 356801 has one side gasket open with NO blocking plate, the other side gasket has a plate has a big hole in it....nothing is BLOCKED OFF.

I still do not remember any blocked off gaskets (SBC) sold by Chevy for anything but trucks.

John, sorry your thread has run off the tracks with talks on late model unrelated gaskets----I'll no longer ruin your nice thread.

Bob-------

The sentence of my thread that you hi-lighted in your question as to part numbers involved the passenger car applications, not the truck applications. So, that's what I responded to. I did not say that the passenger car applications or the truck applications used block-off plates. I was responding to Stu Fox's question regarding truck applications with plates with holes. Light duty and medium duty truck applications also used gaskets with plates with holes on one or both sides. In fact, the GM #356801 was one of those used on trucks from 1973 onward. I don't know of any truck application that ever used block-off plates on both sides although there may have been some. I don't follow truck applications too closely.

Many 1985+ applications, including Corvette, used gaskets with a block-off plate on 1 side. Mostly, these included applications with cast iron heads which still had exhaust cross-over passages while the PFI manifolds, of course, had no cross-over. PRODUCTION aluminum head applications did not have cross-over passages although the gaskets continued to have un-blocked cross-over ports (block off plates would have been superfluous). Part numbers for the gasket sets with a block-off plate on 1 side included GM #14089151, 10159564, 10046309, and, likely, others.

By the way, I don't consider that any of the discussion here "ruined" John's original post. This is a discussion board and, therefore, we discuss things. The discussion goes wherever it takes us.

[Joe L.]

Re: fuel injection gaskets

I hate to be inordinately thick and I'm a newbie with only 10 years of C1/C2 ownership but now I'm confused...I've been told over the years:

1) F/I intake gaskets have the metal block off plates (apparently a myth promulgated by vendors?)
2) Certain cars had NON-blocked off gaskets but were delivered with thin metal shims you could install yourself
3) F/I gaskets (factory) do NOT have the block off plates.

From what I'm reading from people that know oodles more than me is that #3 is the truth...
But then, did the F/I cars allow the hot exhaust gases to circulate under the F/I "doghouse" -- just like a carbed car.

Trying to learn here so don't kick my teeth in pls...

Frank-------

1) I don't know, for sure, if the FI applications originally used cross-over block-off plates. If someone will post photos of a GM #3772384 gasket set, preferably in a sealed package, we'll know. Several folks have said that they had these but no one's posted photos as of yet;

2) I don't know of any application which had gaskets with open exhaust cross-over ports AND was delivered with block-off plates for owner installation. 1969 L-88 might have been built with gaskets with the exhaust cross-over blocked ( I have a set of these gaskets, GM #3955528, but I'm too sore right now to go out and dig them out);

3) See my answer to (1). Also, as I've mentioned, the reproductions of the 1960-65 FI gasket set do have the block-off plates. Whether, or not, this is correct, I do not know.

With respect to your last question, the 1957-65 FI Corvettes did not allow hot exhaust gasses to circulate under the "doghouse". There was no cross-over in the FI adapter manifold so no exhaust gasses could ever get under the "doghouse". The only purpose the plates would have served is to prevent the exhaust gasses from directly contacting the flange surface of the adapter manifold. Among other things, this would have reduced the heat transferred to the adapter manifold at this point. As I mentioned, even if the plates were not originally used, I think their use would be of benefit and no judge will ever be the wiser.

[John D.]

Re: fuel injection gaskets

Your are most welcome Joe Ray.
One more piece of trivia about this gaskets. Not all were black. I have a NOS set that is grayish. Also have a sert that is the typical black.
The repros are not repros. They are stock gaskets that are recut. The two long gaskets are very nice and easily massaged for our judging.
The camel hump has a verticle rib. You need to flatten out the rib and you are done. Then you just have to locate original and expensive end rubbers with the GM logo.