![]() |
#81 | |
![]() ![]() Join Date: Aug 2009
Location: South Dakota/California
Posts: 3,791
|
![]() Quote:
![]() Adapting 91 IH to 90 Heads. Three Dorman 550-013 plugs (two plugs drilled 7/32) were used to restrict IH PVC ports of the 91 IH (90 Heads do not have the required restriction). ![]() |
|
![]() |
![]() |
![]() |
#82 |
![]() Join Date: Nov 2011
Location: Dunbarton NH
Posts: 7,351
|
![]()
Thanks Cliff, I've got some 550-013 and 550-012 on the way. This would have brought my weekend project to a grinding halt. I ASSUME I cannot pop the old ones out of the original IH?
|
![]() |
![]() |
![]() |
#83 |
![]() Join Date: Dec 2004
Location: Jacksonville, FL USA
Posts: 4,645
|
![]()
I never gave that a thought....hummmm? I am thinking they do come out? I can't remember, but we did have a thread that discussed exactly how much trouble it was on the assembly line to do the 90 oil vapor holes. I just don't remember all the particulars.
Sorry I'm so forgetful Steve! ![]() Tom
__________________
1990 ZR-1, Black/grey, #2233, stock. ZR-1 Net Reg Founding Member #316 & NCM member |
![]() |
![]() |
![]() |
#84 |
![]() Join Date: Dec 2003
Location: Arcadia,OK
Posts: 3,384
|
![]()
You could remove the baffles from the 1990 housings, but they would not fit into the 91 housings without machining. The drive plugs fit the cast hole as-is.
__________________
Jerry Downey JERRYS LT5 GASKETS & PARTS http://www.jerrysgaskets.com 1994 ZR-1, Black/Black, Lingenfelter Aerobody, 416cu in, 3.91 gears, coil-over susp, Brembo brakes, etc. 2016 Black-Red, 3LT-Z51 Auto 8-speed. |
![]() |
![]() |
![]() |
#85 |
![]() Join Date: Nov 2011
Location: Dunbarton NH
Posts: 7,351
|
![]()
Thanks guys.
Jerry, I still have to put an order together for you. I think I have a side line on injectors. -Steve |
![]() |
![]() |
![]() |
#86 |
![]() Join Date: Nov 2011
Location: Dunbarton NH
Posts: 7,351
|
![]()
Ended up using the Dormann 555-012 plugs. flattened them in a vise to make them slightly larger in diameter. Drilled 7/32" holes in two of them and drove them in place with a 3/8" extension. Looks good, lets hope it works good.
|
![]() |
![]() |
![]() |
#87 |
Join Date: May 2007
Location: Chicagoland, IL
Posts: 9,696
|
![]()
Someone had asked about the plenum and IH I have for sale. They have a 90 and so the issue of oil port restriction came up. Searched the forum and came up w this thread. For grins, and since different people were using different sized Dorman plugs, I decided to measure the 2 sets of IHs I have.
One is a NOS w a manuf date of Sept.89, the other was on a motor and they were made 1 year later. Here's a picture comparing the two ports. The dimensions are 1 5/32" 29.32mm 1 1/32" 26.25mm The larger ports are the earlier NOS IH. ![]()
__________________
[SIGPIC][/SIGPIC]Former Membership Chairman Former ZR-1 Registry - BOD 1972 Corvette 4speed base Coupe SOLD long time ago 1984 Corvette Z-51/4+3 SOLD 1992 Corvette ZR-1 Aqua/Gray #474 SOLD 1992 Corvette ZR-1 Black Rose/Cognac #458 2014 Honda VFR Interceptor DX |
![]() |
![]() |
![]() |
#88 |
![]() Join Date: Dec 2003
Location: Arcadia,OK
Posts: 3,384
|
![]()
The top picture is of the same injector housing used for 90~92. The machine work to increase the port diameter to 1-5/32" is obvious and was done at Mercury in preparation for the baffle to be installed. The baffle was just never installed and it would work just fine on 91~92 models, just as it is, without the baffle installed. Some like this were probably installed on early 91 engines.
The bottom picture is of an "un-machined" port and would have been installed on 91~92, (can't see the injector bores so I am assuming it's the 90~92 style).
__________________
Jerry Downey JERRYS LT5 GASKETS & PARTS http://www.jerrysgaskets.com 1994 ZR-1, Black/Black, Lingenfelter Aerobody, 416cu in, 3.91 gears, coil-over susp, Brembo brakes, etc. 2016 Black-Red, 3LT-Z51 Auto 8-speed. |
![]() |
![]() |
![]() |
#89 |
Join Date: May 2007
Location: Chicagoland, IL
Posts: 9,696
|
![]()
Jerry,
Correct, they are both 90-92 style injector housings.
__________________
[SIGPIC][/SIGPIC]Former Membership Chairman Former ZR-1 Registry - BOD 1972 Corvette 4speed base Coupe SOLD long time ago 1984 Corvette Z-51/4+3 SOLD 1992 Corvette ZR-1 Aqua/Gray #474 SOLD 1992 Corvette ZR-1 Black Rose/Cognac #458 2014 Honda VFR Interceptor DX |
![]() |
![]() |
![]() |
|
|