headers and oil filter clearance

grumpyvette

Administrator
Staff member
Late-model Corvette LT1 V8s use a space-saving offset filter adapter. On many tight custom installations, this assembly can eliminate the need for a remote oil filter and all of the extra complex plumbing. The offset mount fits Chevy engines machined for the standard PF25 or PF35-style filter, but it requires the skinnier PF52 filter.part # 12556204) normal cost $about $90.00
the gaskets are # 88893990 ($3.40)
bolt # 14092398 $3.84
fitting# 462659 $5.49
keep in mind that some combinations of really useful high capacity baffled aftermarket oil pans with extended sumps and some headers that you use to produce better hp,make accessing the oil filter without removing the headers damn near impossible
getimage.php.jpg

http://www.cantonracingproducts.com/cgi ... ey=15-240M

Installation of the 92-95 Corvette offset Oil Filter Adapter

Postby Mark_ZZ3 » Sun May 04, 2003 2:05 pm
Howdy,

Below is information and pictures of my installation of the 1992-1995 Corvette LT1 off-set oil filter adapter.

The reason for the install was to provide added clearance for exhaust and to make changing the oil filter easier.

Simple Rules: Each engine swap is different. Some need more clearance than others. There are more than one way to achieve the same results.

Here are the parts you need for the swap:

ofs1.jpg


Cost (approx.) :
- Adapter - $40
- Gaskets - $5
- Bolts/Washers - $2
- filter - $2

Installation:

The swap is very simple.

- Drain the oil.
- remove fitler
- Wipe down any oil/dirt/etc.
- remove existing adapter and bolts
- clean again
- assemble new adapter with gaskets.
- install new adapter
- torque bolts to 14-19 ft-lbs
- install new filter
- check for leaks

osf4.jpg



Here is a picture of the old parts and the new parts:
osf7.jpg


Notice that the old bolts are special. The are a 5/16th bolt but the hex head is that of a smaller bolt. This is for clearance reasons.
osf8.jpg

osf9.jpg

Note that my picture has standard grade 5 bolts with the 1/2 socket. In the first picture, top right there is a small picture of the interference between the bolt heads and the adapter. Thus you NEED cap head bolts if you want to torque it correctly OR you can buy the correct bolts from GM, but they are not cheap.


General Notes:

- Make sure that your adapter fits correctly. Most V8 blocks should be machined for the same distances, but I suspect there was variances over the years. Thus if you have a 1969 block, it might not work. If you have a 1987-up, it should fit correctly since oil coolers were available from the factory and used the same idea.
- GM release a bulletin about oil leaks. See below for info. The fix is to install a washer under the bolt. I used Grade 8 washers as they are manufacturer to tolerances unlike the grade 1-5 crap you get.

That's it. I hope this is useful to those that want to do this swap.

Tech-articlely,
Mark.


Subject: PRODUCT CAMPAIGN 92C08 - OIL LEAK AT OIL FILTER
Model and Year: 1992 CHEVROLET CORVETTE
Source: Chevrolet Product Campaign
Bulletin Number: 92C08 - (06/15/1992)
TO: All Chevrolet Dealers
BULLETIN REPRINT
This bulletin was originally sent as a DCS bulletin (Administrative Message 01-358) to all dealers on October 10, 1991. The DCS bulletin can now be discarded and this bulletin retained in its place.
General Motors has determined that certain 1992 Chevrolet Corvettes with LT1 engines may develop an oil leak at the oil filter area.
To prevent this condition, dealers are to install washers under the oil filter adapter bolts.
Owners of vehicles involved in this campaign are being contacted by the Chevrolet Customer Assistance Center (CAC) on a branch-by-branch basis in conjunction with Product Emission Campaign 92C11. Refer to 92C11 for details.
VEHICLES INVOLVED
Involved are certain 1992 Chevrolet Corvettes with LT1 engines built within the following VIN breakpoints:
PLANT YEAR MODEL PLANT CODE FROM THROUGH
1992 Y-Car Bowling Green "5" N5100001 N5102614
THE INVOLVED VEHICLE LISTINGS BEING PROVIDED FOR 92C08 WILL CONTAIN ALL VEHICLES WHICH REQUIRE CAMPAIGN ACTION AT THE TIME THE DCS BULLETIN WAS SENT OUT IN OCTOBER, 1991. NOTE THAT SOME OF THESE VEHICLES HAVE BEEN REPAIRED SINCE THE DCS BULLETIN WAS SENT TO DEALERS. THESE VEHICLES DO NOT REQUIRE FURTHER OIL FILTER ADAPTER CAMPAIGN ACTION BUT MAY REQUIRE CAMPAIGN ACTION UNDER CAMPAIGNS 92C10 (LOWER TRIM PANEL/BRAKE PEDAL INTERFERENCE) AND/OR 92C11 (OPTI-SPARK DISTRIBUTOR). DEALERS CAN VERIFY CAMPAIGN STATUS BY USING VISS.
Involved vehicle have been identified by Vehicle Identification Number Computer Listings. Computer listings contain the complete Vehicle Identification Number, owner name and address data, and. are furnished to involved dealers with the campaign bulletin.
These listings may contain owner names and addresses obtained from State Motor Vehicle Registration Records. The use of such motor vehicle registration data for any other purpose is a violation of law in several states. Accordingly, you are urged to limit the use of this listing to the follow-up necessary to complete this campaign. Any dealer not receiving a computer listing with the campaign bulletin has no involved vehicles currently assigned.
OWNER NOTIFICATION
In conjunction with Product Emission Campaign 92C11 (Opti-Spark Distributor) and Product Campaign 92C10 (Lower Trim Panel/Brake Pedal Interference), owners of vehicles involved are being contacted by the Chevrolet Customer Assistance Center (CAC). Dealers will be notified by DCS when owner contacts by CAC will begin in their branch. Owner letters will also be sent after a CAC contact has been attempted by CAC within each branch (see copy of owner letter included with this bulletin).
DEALER CAMPAIGN RESPONSIBILITY
Dealers are to service all vehiclEs subject to this campaign at no charge to owners, regardless of mileage, age of vehicle, or ownership, from this time forward.
Whenever a vehicle sub.ect to this campaign is taken into your new or used vehicle inventory, or it is in your dealership for service in tha future, you should take the steps necessury to be sure the campaign correction has been made before reselling or releasing the vehicle.
Owners of vehicles recently sold from your new vehicle inventory are to be contacted by the dealer according to DCS instructions, and arrangements made to make the required correction according to instructions contained in this bulletin.
PARTS INFORMATION
Parts required to complete this campaign are to be obtained from General Motors Service Parts Operations (GMSPO). To ensure these parts will be obtained as soon as possible, they should be ordered from GMSPO on a "C.I.O." order with no special instruction code, but on an advise code (2).
Part Number Description Quantity
----------- ------------ ---------
00120393 Washer 2
25010908 Oil Filter (PF51) 1
SERVICE PROCEDURE
1. Inspect bottom side of center console cover near label for orange dot.
If orange dot is present, no further action is required. Proceed to stop 14.
If no orange dot is present, vehicle requires washers under the oil filter adapter bolts. Proceed to step 2.
2. Remove oil filter.
3. Remove forward adapter bolt.
4. Add washer (PIN 00120393) under bolt head.
5. Reinstall bolt with washer and tighten, but do not torque at this time.
6. Remove rearward adapter bolt.
7. Add washer (PIN 00120393) under bolt head.
8. Reinstall bolt with washer and tighten.
9. Torque both bolts to 14-19 lb. ft.
10. Install new filter PF51 (PIN 25010908) and tighten 3/4 to 1 full turn after initial seal contact.
11. Add new (synthetic) oil as required.
12. Run engine and check for leaks.
13. If leaks are found, replace gasket and seal.
14. Install campaign identification Label.
CAMPAIGN IDENTIFICATION LABEL
Each vehicle corrected in accordance with the instructions outlined in this Product Campaign Bulletin will require a "Campaign Identification Label." Each label provides spaces to include the campaign number and the five (5) digit dealer code of the dealer performing the campaign service. This information may be inserted with a typewriter or a ball point pen.
Each "Campaign Identification Label" is to be located on the radiator core support in an area which will be visible when the vehicle is brought in for periodic servicing by the owner. Additional "Campaign Identification Label can be obtained from DAC.
Apply "Campaign Identification Label" only on a clean, dry surface.
CLAIM INFORMATION
Submit a Product Campaign Claim with the information indicated below:
* *** REPAIR PERFORMED PC FAILED PARTS CC-FC LABOR LAB OTH NET PART # ALLOW OP HRS HRS AMT
Inspect - Orange Dot Present - No SK-00 V7130 0.2 0.1 Action Required
Inspect - No OrangE Dot Present - Add 3 25010908 SK-00 V7131 0.6 0.1 $#.## washers And Install New Oil Filter
*Campaign Administrative Allowance.
**The "Parts Allowance" should be the sum total of the current GMSPO Dealer Net price plus 30% of all parts required for the repair.
***The $#.## identified in the "Net Amount" column should be submitted as the cost plus 30% for 1 quart of engine oil (synthetic) or appropriate substitution - Mobil 1 used in conjunction with V7131.
Dealers will automatically receive the correct labor and material allowance based on the labor operation performed.
Refer to the Chevrolet Claims Processing manual for details an Product Campaign claim Submission.
General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition

Make sure to use grade 5 or higher bolts, as the 14-19 ft-lbs is higher than anything under grade 5. Stainless is out of the question too, unless you know the exact composition of it. Most stainless bolts are grade 2, although I have seen some that are grade 5. Be safe, get the grade 5 or higher.


Before and After:

Here is the results. You can see how much room I gained with the adapter install. Now I can replace that bad bend on the exhaust manifold with a free-er flowing one. I suspect that bend is worth 10 hp at 5000 rpm. That may sound like a lot, but trust me when I say it is restrictive.

Zoom in (real dimensions: 800 x 600)

osf10.jpg

osf11.jpg

osf12.jpg

osf13.jpg

osf14.jpg

osf15.jpg


555-51715.jpg

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