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Clifford Performance 6=8

Discussion in 'Intermediate CJ-5 and CJ-6 Tech' started by Raven74CJ5, Nov 30, 2018.

  1. Nov 30, 2018
    Raven74CJ5

    Raven74CJ5 New Member

    san diego,...
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    Jun 13, 2018
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    When I was growing up the most eager upgrade for most people with jeeps was to put this Clifford Performance Upgraded intake and exhaust kit on it. These kits include either a single or dual 2bbl intake, either a single or dual 38mm weber carb, fuel regulator and header. Looking at it, it doesn't sound like a bad deal the single carb set up gives 70% more hp & tq over stock and the dual carb set up does 120 % more.

    So I guess my question is has anyone had any type of experience with this company or their products? If so do you have any input on their products.

    For those who haven't seen or heard about them this is the link for the site:

    Jeep
     
  2. Dec 1, 2018
    Chilly

    Chilly Active Member

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    Looks like high RPM equipment. Is that the goal?
     
  3. Dec 1, 2018
    Chilly

    Chilly Active Member

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    May I comment further despite having no experience with their products?
     
  4. Dec 1, 2018
    timgr

    timgr Jeepin' Nerd Sponsor

    Medford Mass USA
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    I will comment even though I have no personal experience with these products.

    From what I've read, the Clifford stuff seems to be well made and function well, but the pieces are quite expensive. There may have been an era when a 4V intake manifold for the 258 was a viable product, but I think that today it has passed its era. The percent improvements claimed for these aftermarket parts has always impressed me as ... "optimistic", being exceptionally charitable.

    If you are interested in hot-rodding a 258, I'd suggest you first explore the (many!) junkyard enhancements for the 258 that are way less expensive than the Clifford products. I would also mention that the 258 engine, with its very long stroke, starts out with a distinct disadvantage if power is your objective. Horsepower is engine speed (RPM) times torque, and the torque of an undersquare engine like the 258 (3.75"x3.9") peaks at a lower RPM than an engine with a shorter stroke. This is one reason why the 4.0L (242) AMC six makes so much more power than the 258 - it is an oversquare engine (3.88x3.41).

    [​IMG]

    If you do your homework, there are plenty of avenues to upgrade the 258 for more performance. To me, the Clifford products are one of the least appealing of them.
     
    Raven74CJ5, 73 cj5 and Bowbender like this.
  5. Dec 1, 2018
    Chilly

    Chilly Active Member

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    Tim conveyed my thoughts as well, and with considerable more diplomacy than I would have employed.
     
  6. Dec 1, 2018
    heavychevy

    heavychevy Sponsor Sponsor

    Danielsville georgia
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  7. Dec 1, 2018
    Sierra Bum

    Sierra Bum Member

    The High Sierra
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    I did some business with them in 2011. I put in a mildly modified Ford 300 I6 in an 86' F150. I had some of the Clifford stuff on it. I was just wanting something different. There was a performance improvement but not as much as I was hoping for. And I never got it to run right. I would have been happier with a V8.

    The guy who runs the business works out of his garage and had purchased or acquired the business from the original owner/developer. It seemed like there was lots of old stock leftover he was trying to get rid of. Nice enough guy though.

    I don't have any experience with the 258, but with a Jeep I'd be looking at fuel injection.
     
  8. Dec 1, 2018
    mrtii

    mrtii 1972 cj51986 cj7 Sponsor

    gilroy, California
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    I installed a mopar fuel injection kit for my 1986 cj7 with a 258, and was able to shed most of the poor intake system for a superior system in every respect expect cost. fuel economy shot up 4 mpg, driveablility, cold start,reliability since 2001 when I did this, I also improved emissions in all measured exhaust components., and in California where I live that is something, but alas California still classifies my vehicle as a gross polluter and I have had to go to the referee a few times due to most smog shops do not except that I am smog legal even now., I like those above believe that carborator induction systems except for historical vehicles, have seen there days like blacksmiths and others vanish,
     
  9. Dec 1, 2018
    Oldriginal86

    Oldriginal86 Member

    Pasadena, Md.
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    I used the header they make for the 134 and noticed no improvement in anything other than it looked cool.
     
  10. Dec 1, 2018
    numbersix

    numbersix Newberg, Oregon

    Oregon
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    I purchased a Clifford intake manifold for my 258, very nice quality but don't expect quick shipping. From what I've heard, they do them in batches once they get enough orders. It took almost 3 months to get my manifold. My CJ wasn't operable at the time so it wasn't a big deal, it might be for someone else. I'm also running Hedman headers, grinding and sanding was required to make them work the intake. My only real complaint about this intake is you are completely on your own regarding throttle linkage. I've not been able to drive the jeep yet so I can't speak to performance. The idle is much smoother, but I suspect that is my new distributor and Summit CDI module.
     
  11. Dec 1, 2018
    timgr

    timgr Jeepin' Nerd Sponsor

    Medford Mass USA
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    I hope we did not chase off the OP with our negative comments!

    The Mopar multiport injection kit for the 258 is pretty neat, but not cheap. It's almost identical to the Mopar/Bosch MPI system that came from the factory with the 4.0L HO engine, except for 1) the intake manifold fits the 258 (the HO head is different), and 2) it comes with a kit to mount the crank position sender (CPS) on the front of the engine. If it were for me, today I would take the 4.0L HO engine complete and drop that in to replace the 258. Novak will modify your bellhousing to work with the original CPS, or you can get a kit from HESCO to front-mount the CPS, like the Mopar kit for the 258. The 4.0L HO is rated at 180 HP, compared to the 110 for the 258... more than a 60% gain!

    Even the '87-91 non-HO 4.0L would make nice swap if you found a donor with a good one. The computer for the native Renix (Renault-Bendix) EFI can be replaced by a Megasquirt board, which has a special Renix mode. https://www.cleggengine.com/downloads/specs/JEEP_4.0_PERFORMANCE_SPECS.pdf
     
    Last edited: Dec 1, 2018
    Jrobz23 and 73 cj5 like this.
  12. Dec 3, 2018
    Raven74CJ5

    Raven74CJ5 New Member

    san diego,...
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    Thanks everyone for your input. I'm honestly not looking for performance out of my CJ... that will never happen unless I do some considerable mods to it and I would rather keep her as close to stock as I can. Especially since I'm only able to get her up to 65 on the freeway with the set up I'm running now. What I'm basically looking for is something that gets better gas mileage and better on cold starts. I'm not wanting more horsepower or more torque but I do want a cleaner looking set up over the hoard of vacuum lines that run all over the engine compartment with what I currently have.

    Any further input would be greatly appreciated.
     
  13. Dec 4, 2018
    Chilly

    Chilly Active Member

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    Is this for your 74 CJ5? I wouldnt expect too much clutter on that engine, buy I see you are in CA so that could be the difference.

    A thorough ignition tune-up and carb cleanup (rebuild?) Can do wonders.
     
    Jrobz23 likes this.
  14. Dec 4, 2018
    Chilly

    Chilly Active Member

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    Also, when decluttering an engine one must understand the function of every element of clutter. Some of it helps with emissions and hinders performance, some of it helps with emissions and doesnt affect performance, some of it actually helps engine performance and isnt related to emissions at all.
     
  15. Dec 4, 2018
    timgr

    timgr Jeepin' Nerd Sponsor

    Medford Mass USA
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    Why do you think your top speed is 65? These Jeeps are capable of speeds way past the legal limit on the highway. BTDT. If you really have 4.10s (a ratio that the factory never offered), you should be at roughly 3000 RPM, which would be fine for a healthy 258.

    What mileage do you get now? I usually got around 14 mpg or maybe a little better with my 258 CJ-6 back in the day, as I recall. About the only thing you can do that will have much of a positive effect on mileage is slow down. It's an issue of aerodynamics. In San Diego, you should have no trouble with cold starts unless something is broken or badly adjusted. A couple of pumps, turn the key and it should start and you can drive away.

    Engines and engine bays are very uncluttered in this era, especially a Jeep with an inline engine. Some cleaning and engine enamel will make things look a lot tidier. I agree with Chilly, don't remove anything until you understand what you are doing. There is a 1974 TSM here Jeep® 1974 TSM online that you can read and download for free. It has a section about the YF carburetor that came with your Jeep that explains its function very well.
     
  16. Dec 5, 2018
    Raven74CJ5

    Raven74CJ5 New Member

    san diego,...
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    Thanks Tm for the info... I actually already have the TSM for my jeep my dad gave it to me when he gave me the jeep. But back to what you mentioned, yes at 65 I am doing roughly 3000 rpm's on the freeway. Which I know doesn't sound like a high rpm but when I'm driving she sounds like she is screaming down the road even though only doing 60 to 65. It has been a while since I actually calculated out what my miles per gallon but if I remember right it was about 14 to 15 mpg. And as for the cold starts I'm assuming there must be something damaged with this carb since the choke doesn't like to work sometimes in the early morning when I'm leaving for work. If I do leave prior to getting her warmed up she tends to spit and sputter through the carb. Either way purchasing a new carb is in my future.
     
  17. Dec 5, 2018
    timgr

    timgr Jeepin' Nerd Sponsor

    Medford Mass USA
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    What have you done with the carburetor? If the carburetor has never been rebuilt, it's way past due. The choke of the YF is of conventional design, using hot air from the exhaust manifold to activate the thermal spring and open the choke plate. The hot air comes from a pocket in the exhaust manifold in which the hot air tube (to the carburetor) rests loosely. Not much to it - read the TSM and it will tell you about how it works and how to adjust its operation.

    Again, San Diego is a dead easy environment for carburetor and choke operation. You hardly need a choke there. The choke's purpose is to richen the fuel mixture and overcome the fuel's tendency to condense on the inside of the cold intake manifold. There is also a manifold heater, consisting of a flap that directs hot exhaust gas against the intake manifold where the two manifolds are bolted together. You hardly need that feature in San Diego - proper operation of the choke should be sufficient for hassle-free driving.
     
    Last edited: Dec 5, 2018
  18. Dec 8, 2018
    Raven74CJ5

    Raven74CJ5 New Member

    san diego,...
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    I know the carb probably should be rebuilt but Im not even sure if the carb I have is a YF, I remember my dad telling me it was switched out years ago for a 1 bbl holley. I could be wrong so I would have to look and verify to see what carb I actually do have. I'm familiar with the exhaust thermal spring as I have replaced that exhaust manifold once before because of the spring wore out and broke on my last one.
     
  19. Dec 8, 2018
    steve1973

    steve1973 Member

    Charlestown, RI
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    Everything Tim said. Best upgrade for the $ I did on my 73 was a Msd billet distributor, msd6 digital box, wires, coil and iridium plugs. That is more of wake up and kick in the pants then the Weber 38 that is also on it. The hi power ignition can overcome a problematic choke in warner weather. With a working choke it starts easily down to at least 5 to 10 below zero. BTW, factory listed top speed of an intermediate with the 6 is 81MPH. No top, no sound deadening material and all the wonderful mechanical noises, of course it will be load. Don’t worry, it’s fine and 3000 isn’t screaming. I don’t have a tach, and happy I don’t. It’s one less thing to thing to measure against the sea of misleading info out there
     
  20. Dec 8, 2018
    Raven74CJ5

    Raven74CJ5 New Member

    san diego,...
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    Jun 13, 2018
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    Thank you everyone for your input and advice... I believe the best route for me to go now is to either have this carb rebuilt or even find a new original YF carb for my jeep. I have priced them out not expensive at all less than $100 for the carb. I am however going to need to see if they have a diagram in my tsm to properly route the vacuum lines that go to the intake and everything for this system.

    With this project I have been going off of what my dad has told me he did to the jeep or what he believes the jeep had when he bought it. So I'm learning a lot about what is actually on the jeep versus what he told me was there.

    Again thank you all for your help

    Neal
     

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