- I have the RCR motor mounts. It can fit in two directions and it will impact motor fitment. There are two upright threaded tubes welded to the outside edge of a horizontal cross member that attaches to the main chassis frame (see picture).
Question 1: Are the vertical uprights oriented forward or aft?
Question 2: The GM engine mount holes (bottom ones) and the vertical RCR engine mount "rail" are off just enough (estimate 1/16) so they do not mate. (I seem to recall someone else had this issue) - Is it best to shim the GM mount at the engine or
- Is it better to make the GM mount hole an "oval" vice round (I wouldn't think this would allow the engine to slide left or right once torqued down.
RCR Motor Mounts - which direction do they fit
- Thread starter Dan carter
- Start date
I put the motor mount so that the mounts are facing towards the back.
Gents
Thanks for the clarification on the mount.
Mike I note in your picture that my mounts differ from yours. Are you using an LS3 block? If so, than I have another GM problem (#3).
Did either of you experience a problem with the holes/mounts not lining up. I am off by 1/4 inch.
Thanks for the clarification on the mount.
Mike I note in your picture that my mounts differ from yours. Are you using an LS3 block? If so, than I have another GM problem (#3).
Did either of you experience a problem with the holes/mounts not lining up. I am off by 1/4 inch.
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Dan, I have the stock crate LS376 block. IIRC the mounts came with my SLC kit - I ordered the full monty (all stages) up front.
Stage 9 – Drivetrain fitting package $3,805
Stage 9 – Drivetrain fitting package $3,805
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- Engine mounts
Mike
I may be confusing the question with semantics, aka a rose by any other name......I was curious about the second picture....the brackets on your block. My crate motor did not come with engine "brackets" so I purchased "C6 Corvette" brackets. To me yours seem different somehow.
I ask since the RCR motor mount and the engine brackets are out of alignment by about 1/4 of an inch. I had 3 engineers and 1 physicist, yes a physicist look at the car today and got 4 differing solutions. My hot rod buddy suggested I simply elongate the engine bracket hole by 1/8 inch on both sides to mate up. The other engineering solutions were much more involved.
I thought I read about this problem elsewhere in the forum, but don't recall a proven solution. I presume you had no fitment issues.
I may be confusing the question with semantics, aka a rose by any other name......I was curious about the second picture....the brackets on your block. My crate motor did not come with engine "brackets" so I purchased "C6 Corvette" brackets. To me yours seem different somehow.
I ask since the RCR motor mount and the engine brackets are out of alignment by about 1/4 of an inch. I had 3 engineers and 1 physicist, yes a physicist look at the car today and got 4 differing solutions. My hot rod buddy suggested I simply elongate the engine bracket hole by 1/8 inch on both sides to mate up. The other engineering solutions were much more involved.
I thought I read about this problem elsewhere in the forum, but don't recall a proven solution. I presume you had no fitment issues.
Mike/Eric
Can either/both share a picture of your serpentine setup......did you use the CTSV alternator bracket?
Can either/both share a picture of your serpentine setup......did you use the CTSV alternator bracket?
Dan, I ordered the front accessory kit when I also purchased the new crate, GM wiring harness etc. If I recall correctly it was the "tall & narrow" LS1/F Body type kit or as others call it the CTS-V setup. Here's a link with also individual part numbers. I did not use the PS bracket, but upon further inspection it looks like it could be cut down and modified with use of a generic pulley - I think Bill/Rumbles modded his P/S bracket with success?:
Don't quote me on this but the mounts may be stock GM C5/LS6 -- I forget. The C5 & C6 mounts are different I think - be careful. Ask Fran - they'll know what works.
Chevrolet Performance 19155066, Chevrolet Performance LS Engine Serpentine Belt Drive Systems | Chevrolet Performance
BTW: I spent hours/days of time trying to make the GM supplied A/C compressor/bracket system work. The main issue was trying to find a compressor pad/adapter to work correctly with the supplied Denso 10S17F compressor. Finally gave up and used Fran's compressor bracket and a Sanden compressor.
Engineers.... I on occasion have to call upon them for my clients and are present during on-site meetings. I found that one engineer, the meeting is 20 minutes. You have 2-3 with you at the same time - set aside a couple hours.......ya know what I'm sayin'
Don't quote me on this but the mounts may be stock GM C5/LS6 -- I forget. The C5 & C6 mounts are different I think - be careful. Ask Fran - they'll know what works.
Chevrolet Performance 19155066, Chevrolet Performance LS Engine Serpentine Belt Drive Systems | Chevrolet Performance
BTW: I spent hours/days of time trying to make the GM supplied A/C compressor/bracket system work. The main issue was trying to find a compressor pad/adapter to work correctly with the supplied Denso 10S17F compressor. Finally gave up and used Fran's compressor bracket and a Sanden compressor.
Engineers.... I on occasion have to call upon them for my clients and are present during on-site meetings. I found that one engineer, the meeting is 20 minutes. You have 2-3 with you at the same time - set aside a couple hours.......ya know what I'm sayin'
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Thanks. I will ask Fran on the mounts before I alter anything.
Yes the "meeting" took 4 hours, but beverages were involved........:laugh:
Yes the "meeting" took 4 hours, but beverages were involved........:laugh:
Ken Roberts
Supporter
The C6 Corvette mounts are correct for a LS engine. I had to slot my mounting holes as well. I compensated by using thicker and larger flat washers on the bolts.
The correct belt wrap for the accessory drive components is on the Corvette beltline. The F Body, Truck and new Camaro beltlines don't fit. They stick out too far. If you don't custom make your accessory drive set up (as Will and Bill has done) then you have approx. three choices. CTS V, G8 GXP or the RCR factory kit. These three choices are on the Corvette belt line.
Which LS water pump are you using? Is the outlet on the left or the right of the pulley? Newer pump outlets were on the left. Earlier pump outlets were on the right.
The correct belt wrap for the accessory drive components is on the Corvette beltline. The F Body, Truck and new Camaro beltlines don't fit. They stick out too far. If you don't custom make your accessory drive set up (as Will and Bill has done) then you have approx. three choices. CTS V, G8 GXP or the RCR factory kit. These three choices are on the Corvette belt line.
Which LS water pump are you using? Is the outlet on the left or the right of the pulley? Newer pump outlets were on the left. Earlier pump outlets were on the right.
Ken
I purchased the accessory drive system from RCR, and had RCR modify my LS3 water pump. see the picture.
I will go to my dealership and price out the alternator mounts and go with the best deal. BTW, how many AMP output did you use? I have the ISIS system and I here it is a battery killer.
I really hate to elongate the hole, but if I must. I wonder if anyone has notified RCR that the jig may be off.
Thanks
I purchased the accessory drive system from RCR, and had RCR modify my LS3 water pump. see the picture.
I will go to my dealership and price out the alternator mounts and go with the best deal. BTW, how many AMP output did you use? I have the ISIS system and I here it is a battery killer.
I really hate to elongate the hole, but if I must. I wonder if anyone has notified RCR that the jig may be off.
Thanks
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Ken Roberts
Supporter
I'm using the Pontiac G8 GXP alternator and bracket. It's rated at 140amps. Your best bet is the CTS V.
If you purchased the RCR accessory drive set up then why are you looking for an alternator Dan?
I always recommend changing out the spring loaded belt tensioner for a solid one like the Katech tensioner. I just saw a used one for sale for $50.
If you purchased the RCR accessory drive set up then why are you looking for an alternator Dan?
I always recommend changing out the spring loaded belt tensioner for a solid one like the Katech tensioner. I just saw a used one for sale for $50.
Did not get an alternator with the accessory kit. Is there supposed to be one?
Ken Roberts
Supporter
Yes ...I would assume it would include an alternator. I believe they used a truck alternator with an in house fabricated bracket.
Personally it wasn't my favorite set up. The drive kit should include a tensioner, idler, alternator and belt.
I better take another look. I have some of it, don't recall an alternator. I will advise after another search...........:drunk:
Can not seem to find details on what is included in the kit. I bought one, got some parts but no alternator/bracket. I will ask RCR, what's in the kit.
thanks
thanks
Fran Hall RCR
GT40s Sponsor
Alternator bracket is a pair of spacers , there is nooint per se as the alternator we recommend mounts to the block
The GM cast mount needs the holes opened up as we recommend using a larger bolt than GM, hence the larger hole in the chassis engine mount.
We prefit a lot of engines at the shop and don't have any issues that I have been made aware of by the guys, once the hole has been enlarged
I will ask this week
The GM cast mount needs the holes opened up as we recommend using a larger bolt than GM, hence the larger hole in the chassis engine mount.
We prefit a lot of engines at the shop and don't have any issues that I have been made aware of by the guys, once the hole has been enlarged
I will ask this week
Fran
Thanks for checking. I did note that even though the holes may be different diameters, they are not centered on each other. Apparently what builders have had to do is elongate the GM bracket vice drilling a bigger hole.
It Will be interesting to hear their solution. BTW as a reference the GM part numbers are 10349964 and 65.
Try to stay warm up there.
Dan
Thanks for checking. I did note that even though the holes may be different diameters, they are not centered on each other. Apparently what builders have had to do is elongate the GM bracket vice drilling a bigger hole.
It Will be interesting to hear their solution. BTW as a reference the GM part numbers are 10349964 and 65.
Try to stay warm up there.
Dan
