Page 1 of 3 123 LastLast
Results 1 to 20 of 52

Thread: SBC engine and transmission mounting in a YJ.

  1. #1
    Join Date
    Sep 2007
    Location
    Brantford
    Posts
    7,986
    Time Online: 4 Mths 2 Days 17 Hrs 46 Mins 57 Secs
    Avg. Time Online: 10 Mins 7 Secs
    Rep Power
    118

    SBC engine and transmission mounting in a YJ.

    I've done lots of reading and have yet to determine the best way to properly mount the engine and tranny. I have thoughts on how i would like to.

    I do plan on fabricating all of the necessary brackets etc so I'm not interested in people just posting up a link of a M.O.R.E. Mounting kit.

    I also have questions around is it best to use 4 mounts instead of 3. You know 2 for the engine and 2 for the transmission/ transfer case. Is there a rule around this? I have also read that there should be two for every attachment point... IE engine, tranny, tcase. So 6 total.

    I know that some of you guys have done this type of upgrade. What thoughts and experience are you willing to share? Pics will help me to understand as well....



    Thanks in advance.
    My latest project... Collection of Parts

    Other stuff... Building a doubler, D300 Flip kit

    Quote Originally Posted by Deadman 94 xj View Post
    "Coil springs are for ballpoint pens and pogo sticks".
    ебут раком

  2. #2
    Join Date
    Sep 2005
    Location
    somewhere
    Posts
    691
    Time Online: 6 Mths 2 Days 6 Hrs 16 Mins 41 Secs
    Avg. Time Online: 15 Mins 2 Secs
    Rep Power
    13
    I built my engine mounts from poly bushings I had lying around and some 3/16" steel. I prefer to do it myself versus bolt on kits.... bit of Scottish cheapness but more I like to fab after sitting as a desk all week.

    Not sure what engine and trans you are going with.... but really see no point in going to a four(or more) point mounting system. My 3 point mounting hasn't been an issue in 2 years.... but I have a fairly short driveline 350/Jeep T18/Dana 20). But even the GM's I've had only had a 3 point mount and they were 700r4 with 241's.

    Have at her and post up some pics. I'm frickin bored of playing with my electrical gremlins on my Vette.... I need pictures of fabbin 'n stuff.

    P.S. the power of a SBC is totally overkill for a Jeep.... but its sooo much fun and sounds sooo good--- way better than a inline 6 weezer.

  3. #3
    Join Date
    Oct 2008
    Location
    Newmarket Ont
    Posts
    166
    Time Online: 6 Days 19 Hrs 30 Mins 59 Secs
    Avg. Time Online: 33 Secs
    Rep Power
    10
    Have done 2 SBC's into YJ's, and lots of other SBC's into other chassis over the years. I have to mention also, I have had NEGATIVE results dealing with M O R E..ie, they bill ya, but dont ship..so if you ARE uding them, use VISA so u can get your $$ back.

    But anyway, the BEST mounts, and by far the best service has been NOVAK. Thier mounts give you lots of options, and allow you to adjust side to side, (handy for swappin in an 8.8, or other offset pinions) and up and down (although to a lesser degree)
    Thier website is comprehensive, and lists all the possiblitys for most any engine swap into a Jeep. They ONLY DO JEEP. They also supply vertually everything you need.

    You do NOT need 4 mounts..the engine/trans, case, needs to be able to flex a bit. Novak also supplys a beefed up trans mount.

    In the two I have done, I used Hedman block hugger headers (cheaper and fit great) I also used GM TH350 trannys on both..Would suggest 700R4 is probably a better bet, especially if using low gears or smallish tires.
    What you do get, in the end, is a Jeep that you can actually drive, without having to gear down for every hill, even with 38"s. The SBC also lets it handle better, because the weight bias is moved back off the front tires. An iron head SBC weighs less than a 4.0 also.
    Yesterday's HISTORY, Tomorrow's a MYSTERY. LIVE FOR TODAY

  4. #4
    Join Date
    Jan 2009
    Location
    Georgetown
    Posts
    3,442
    Time Online: 5 Mths 3 Wks 5 Days 23 Hrs 16 Mins 16 Secs
    Avg. Time Online: 14 Mins 35 Secs
    Rep Power
    12
    ^^ heard very good things about Novak

    http://www.novak-adapt.com/catalog/e...ts/mmx-wc1.htm

    here's a nice read at novak

    http://www.novak-adapt.com/knowledge/yj_87_95_swap.htm

    some ideas



    Last edited by Pav1; 10-15-2011 at 09:19 AM.

  5. #5
    Join Date
    Sep 2005
    Location
    somewhere
    Posts
    691
    Time Online: 6 Mths 2 Days 6 Hrs 16 Mins 41 Secs
    Avg. Time Online: 15 Mins 2 Secs
    Rep Power
    13
    I have Corvette rams horns exhaust manifolds on mine. They are similar to block hugger headers and sometimes you can find them fairly cheap on KIJIJI. Typical truck SBC manifolds will not work on a CJ but I am not sure about a YJ. The rear dump on the passenger side wants to share space with the firewall.

    I dealt with Novaks for my input bearing retainer/ adapter ring and throwout bearing. They were great to deal with when I found out they hadn't machined the input bearing retainer correctly. They machined a new adapter ring to fit it and it was at my front door in a week.

  6. #6
    Join Date
    Mar 2009
    Location
    binbrook ont.
    Posts
    233
    Time Online: 3 Days 21 Hrs 13 Mins 36 Secs
    Avg. Time Online: 19 Secs
    Rep Power
    9
    i might have what you need 350 700r4 np208 tight headers. i was going to install them in my toyota but rusty frame issues.!! 289 286 0498
    Bryn; 86 chev k5 blazer

  7. #7
    Join Date
    Sep 2007
    Location
    Brantford
    Posts
    7,986
    Time Online: 4 Mths 2 Days 17 Hrs 46 Mins 57 Secs
    Avg. Time Online: 10 Mins 7 Secs
    Rep Power
    118
    Interested in the headers... So you have a PM.

    So let's see more of what guys are doing?

    I also want to do a flat bottom which is partially why I was thinking to use two mounting points for the tranny/tcase. Is there any reason not to go this route?

  8. #8
    Join Date
    Sep 2005
    Location
    somewhere
    Posts
    691
    Time Online: 6 Mths 2 Days 6 Hrs 16 Mins 41 Secs
    Avg. Time Online: 15 Mins 2 Secs
    Rep Power
    13
    I'm almost flat bellied.... the T18 and the D20 clocking just don't allow it without a body lift. I am using a stock GM tranny mount.

    I'll try to grab some pictures tonight. It is pretty amazing what you can go over without scraping once this is done.

    What trans and T case are you thinking of using?

  9. #9
    Join Date
    Sep 2007
    Location
    Brantford
    Posts
    7,986
    Time Online: 4 Mths 2 Days 17 Hrs 46 Mins 57 Secs
    Avg. Time Online: 10 Mins 7 Secs
    Rep Power
    118
    The plan is a 350 TBI married to a 700R4. The NP231 will be backed up with a clocked D300. Check out my build thread there is pics there of the parts as they come together.

    Gonna be a trick build. And it's all coming together. Just need to figure out the mounting.

    Pics will be awesome. Thanks.

  10. #10
    Join Date
    Sep 2005
    Location
    somewhere
    Posts
    691
    Time Online: 6 Mths 2 Days 6 Hrs 16 Mins 41 Secs
    Avg. Time Online: 15 Mins 2 Secs
    Rep Power
    13
    Stretching the wheelbase to fit all that in there?

  11. #11
    Join Date
    Sep 2007
    Location
    Brantford
    Posts
    7,986
    Time Online: 4 Mths 2 Days 17 Hrs 46 Mins 57 Secs
    Avg. Time Online: 10 Mins 7 Secs
    Rep Power
    118
    Already done a stretch. And typically a d300 np231 combo is shorter than a stock np 231.

    But if need be I'll add a couple more inches to the read length wise although I don think it will be required.

  12. #12
    Join Date
    Dec 2005
    Location
    niagara south
    Posts
    665
    My Mood
    Buzzed
    Time Online: 5 Days 25 Mins 27 Secs
    Avg. Time Online: 24 Secs
    Rep Power
    12
    hey jak if ya want i got a Advance adapter SBC cradle band new never used yours if ya want it
    what can i say i got I got a jeep body and a jeep frame ,the rest is ford,chevy

  13. #13
    Join Date
    Oct 2008
    Location
    Newmarket Ont
    Posts
    166
    Time Online: 6 Days 19 Hrs 30 Mins 59 Secs
    Avg. Time Online: 33 Secs
    Rep Power
    10
    Whatever you do, avoid front cradle style engine mounts on an SBC. Reason being, they cause the trans bell housing to crack, by biasing the engine weight to the nose. The stock engine mount position provides the best balance point.
    Personally, I have never had much luck with Advance adapters products. Not to say theres anything wrong with them..just my experiance.
    Trans..I used a TH350 because I had one, and I have been using them for over 40 years, in street rods, race cars, and 4x4's. They are shorter than 700's, so they fit in tighter places, and in a YJ..thats an issue. As an old GM parts guy, I can tell you for sure, AVOID early design 700's..(late 80's to mid 90's) they where JUNK. Also..dont even go around the block with one unless the TV cable is in and working, and dont put one in unless its been fully rebuilt by a licenced tranny guy. Also, in a 4x4, dont even think about a high stall converter, and use the biggest cooler you can fit.
    As far as multiple mount points. The engine and trans needs to be able to move a bit. Reasons being vibrations..first off, it'll be noisy as hell, and annoying. More important, it will eventually vibrate bolts loose, and start cracking parts.
    Flat belly skid plates. I built one for mine, and it works fine. My CJ/YJ combo is shown a few spots down in this forum. It is 2 wd, and lowered about 6". I mounted my engine set back about 6" from stock, and about 2" higher. The firewall and trans tunnel are both cut to fit around the driveline, and the body is sitting right on stock YJ body mounts. (its a glass body, so cutting and moving it was easy) My previous YJ was a 4x4, and I set the engine back in it as well, but it had an Aqualu body, which comes with a big cut out for the distributor, and a massive trans tunnel. I used the same mounts, engine, headers, trans, and a super short 231 case, along with an 8.8. It was featured on Aqualu's website..havent looked for a while.

    Headers. I used Hedman's, but the block hugger design is pretty much all the same for all brands. No steering shaft issues, but the front driveshaft is a close fit..which is why the NOVAK mounts are so versitile..You can slide the engine over to either side, depending on your pinion angles, and to make clearance. On a SBC, the oil filter is close to hitting the front driveshaft, IF the engine is centred. Remember, 8.8's and 60's, have fairly big pinion offsets, and you do need to keep them lined up to at least close.
    I fabricated a true 2 1/2" mandrel bent true dual exhaust system for both Jeeps, out of Dynomax U bends

  14. #14
    Join Date
    Sep 2007
    Location
    Brantford
    Posts
    7,986
    Time Online: 4 Mths 2 Days 17 Hrs 46 Mins 57 Secs
    Avg. Time Online: 10 Mins 7 Secs
    Rep Power
    118
    ^ that is some good info there.

    My plan is to offset the engine t the passenger side slightly to help with the front drive shaft. I was thinking about an inch or so.

    I do plan on allowing movement as I'm not a fan of lots of vibration from the driveline. Rubber mounts are the thought but I'm still thinking of using two on the tranny so that I can get that flat belly. And cutting to make it all fit doesnt scare me.

    Still though. The less cutting the better.

    Quote Originally Posted by scrappy View Post
    hey jak if ya want i got a Advance adapter SBC cradle band new never used yours if ya want it
    Thanks for the offer. But not what I'm looking to do.

  15. #15
    Join Date
    Oct 2004
    Location
    beamsville
    Posts
    1,326
    Time Online: 2 Mths 18 Hrs 57 Mins 48 Secs
    Avg. Time Online: 5 Mins
    Rep Power
    15
    nothing wrong a front mount,.hurst motor mounts were used for years

  16. #16
    Join Date
    Dec 2005
    Location
    niagara south
    Posts
    665
    My Mood
    Buzzed
    Time Online: 5 Days 25 Mins 27 Secs
    Avg. Time Online: 24 Secs
    Rep Power
    12
    Quote Originally Posted by kidstf View Post
    Whatever you do, avoid front cradle style engine mounts on an SBC. Reason being, they cause the trans bell housing to crack, by biasing the engine weight to the nose. The stock engine mount position provides the best balance point.
    Personally, I have never had much luck with Advance adapters products. Not to say theres anything wrong with them..just my experiance.
    Trans..I used a TH350 because I had one, and I have been using them for over 40 years, in street rods, race cars, and 4x4's. They are shorter than 700's, so they fit in tighter places, and in a YJ..thats an issue. As an old GM parts guy, I can tell you for sure, AVOID early design 700's..(late 80's to mid 90's) they where JUNK. Also..dont even go around the block with one unless the TV cable is in and working, and dont put one in unless its been fully rebuilt by a licenced tranny guy. Also, in a 4x4, dont even think about a high stall converter, and use the biggest cooler you can fit.
    As far as multiple mount points. The engine and trans needs to be able to move a bit. Reasons being vibrations..first off, it'll be noisy as hell, and annoying. More important, it will eventually vibrate bolts loose, and start cracking parts.
    Flat belly skid plates. I built one for mine, and it works fine. My CJ/YJ combo is shown a few spots down in this forum. It is 2 wd, and lowered about 6". I mounted my engine set back about 6" from stock, and about 2" higher. The firewall and trans tunnel are both cut to fit around the driveline, and the body is sitting right on stock YJ body mounts. (its a glass body, so cutting and moving it was easy) My previous YJ was a 4x4, and I set the engine back in it as well, but it had an Aqualu body, which comes with a big cut out for the distributor, and a massive trans tunnel. I used the same mounts, engine, headers, trans, and a super short 231 case, along with an 8.8. It was featured on Aqualu's website..havent looked for a while.

    Headers. I used Hedman's, but the block hugger design is pretty much all the same for all brands. No steering shaft issues, but the front driveshaft is a close fit..which is why the NOVAK mounts are so versitile..You can slide the engine over to either side, depending on your pinion angles, and to make clearance. On a SBC, the oil filter is close to hitting the front driveshaft, IF the engine is centred. Remember, 8.8's and 60's, have fairly big pinion offsets, and you do need to keep them lined up to at least close.
    I fabricated a true 2 1/2" mandrel bent true dual exhaust system for both Jeeps, out of Dynomax U bends
    i have to be honest their is a reson i didn't use it and made my own mounts but its a freebee so.......

  17. #17
    Join Date
    Apr 2009
    Location
    St. Catharines
    Posts
    373
    Time Online: 3 Wks 3 Days 13 Hrs 54 Mins 15 Secs
    Avg. Time Online: 2 Mins 1 Sec
    Rep Power
    9
    if you use a front mount ,use a mid mount as well you won't regret it

  18. #18
    Join Date
    Sep 2007
    Location
    Brantford
    Posts
    7,986
    Time Online: 4 Mths 2 Days 17 Hrs 46 Mins 57 Secs
    Avg. Time Online: 10 Mins 7 Secs
    Rep Power
    118
    Quote Originally Posted by stach1 View Post
    nothing wrong a front mount,.hurst motor mounts were used for years
    Just need to understand your suggestion?

    Front mount, side mount, two tranny mounts?

    Could be interesting...

  19. #19
    Join Date
    Oct 2008
    Location
    Newmarket Ont
    Posts
    166
    Time Online: 6 Days 19 Hrs 30 Mins 59 Secs
    Avg. Time Online: 33 Secs
    Rep Power
    10
    Front cradle mounts work ok on something that also has a mid plate, and in a drag car. But this isnt a drag car. A Jeep chassis flexes quite a bit..which is why they use the conical shaped bolts on the skid plate. In mine, with the Novak mounts, when I pull the trans, the back of the engine only drops about an inch. A front mount without a mid, puts too much stress on the bellhousing, and it will eventually crack. Chevys bellhousings are not terribly strong in the first place. In early Vettes, with turbo400's, the case was about twice as thick as a normal car, at the bellhousing, and in 4x4 trucks, they used braces between the engine and the bottom of the trans, to stop flex.
    Novak worked for me, and I can honestly say I wish I had have know about thier design 40 years ago. I have swapped SBC's into probably 30 or more cars and trucks, and the Novak design would have worked in about 80% of them. I also spent 28 years as a GM Parts Manager, and supplied parts to a ton of racers and HP guys, so I know what fits what, and what years interchange, and what breaks where, and why. I'm just sayin

  20. #20
    Join Date
    Sep 2007
    Location
    Brantford
    Posts
    7,986
    Time Online: 4 Mths 2 Days 17 Hrs 46 Mins 57 Secs
    Avg. Time Online: 10 Mins 7 Secs
    Rep Power
    118
    ^ I think I will mount the traditional way and I have an idea that was presented to me for the tranny mounting. overall I believe that this will be a great install. I am looking forward to getting into it soon. almost ready to get started.

    Thanks for the info....

    as for pictures.... do you have any of when you were mounting the SBC?

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •