A better cylinder head

Performance mods and Advanced Stroker discussion.
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I6FAN
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Re: A better cylinder head

Post by I6FAN »

Way back when Silver XJ was having all of his cam-bearing problems, he shared his woes over on Speed Talk. Speed Talk, for those that don't know, was created by a guy named Don Terrill, and when he passed away, a guy named Mike Jones of Jones Cam Designs bought and took over the site. Speed Talk is full of all kinds of very knowledgeable engine builders of ALL types (and theory). I believe it was Mike Jones who finally located the correct cam cores for the later Jeep key-way retention plate-style cams for Silver XJ. Since then he sells his grinds or customs based on that proper core. I think I remember him saying he could make a custom roller cam for the Jeep inline, but it was upwards of $1,500. I believe Mike Jones' father was involved in cams and racing in the '50s and '60s and then took it over, and up, to a whole new level. He has stuff in all kinds of big-name racing, and I believe domestic corporate also. There was another company that was marketing a roller cam, but I believe there was a metallurgy problem between the matching components which resulted in a very limited life piece(s). If I was interested in a roller, Mike Jones would be my first inquiry.

The benefit of a roller over hydraulic doesn't really appear until after ~270ish adv duration ((~220ish @.050") for sbc according to D. Vizard). Being that only about 5%, or less, of the people building the Jeep inline, are building it for higher rpm rigs i.e. drags, sand drags, mud bog, hot street, and sand running, etc. there isn't much of a market justification for a roller, as the other 95% of Jeep builders are looking to build higher torque at low rpm. The roller doesn't benefit that other 95%. If higher rpm is your goal, and the cost isn't an obstacle, then by all mean the custom roller is the obvious choice.
I6FAN
I made it to triple digits!
I made it to triple digits!
Posts: 172
Joined: March 28th, 2010, 9:31 am
Stroker Displacement: 4.2
Vehicle Year: 1987
Vehicle Make: jeep
Vehicle Model: wrangler

Re: A better cylinder head

Post by I6FAN »

Btw, Silver XJ has been somewhat dormant on this site for a while, but he did respond to a question not too long ago. He brought a wealth of knowledge to the table here at Jeep Strokers; was sorry to see him not so active :( (life does go on). Maybe he remembers the Jones Cam Designs roller option I mentioned (that way we get it straight from the horse's mouth rather than its A-- :? :lol: ). What say you Silver XJ?
Randy Bobandi
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Re: A better cylinder head

Post by Randy Bobandi »

I6FAN wrote: January 2nd, 2023, 9:52 am I think I remember him saying he could make a custom roller cam for the Jeep inline, but it was upwards of $1,500.

The benefit of a roller over hydraulic doesn't really appear until after ~270ish adv duration ((~220ish @.050") for sbc according to D. Vizard). Being that only about 5%, or less, of the people building the Jeep inline, are building it for higher rpm rigs i.e. drags, sand drags, mud bog, hot street, and sand running, etc. there isn't much of a market justification for a roller, as the other 95% of Jeep builders are looking to build higher torque at low rpm.
Having a roller cam option could be huge for a lot of us. Huge for the Jeep aftermarket in general. A chopped up, one off cylinder head doesn't really have any effect.

$1500 sounds like the typical number for a custom billet 8620 roller cam. I bet if we bugged Comp long enough, they would cut a few bars of 8620 for us. I know 505 attempted to grind roller lobes onto stock Jeep cams. Steel rollers on cast iron lobes obviously didn't last very long, especially on a small base circle.

The theory is that it is harder to justify an inline 6 LS7 head than a roller camshaft. Well, naturally aspirated, none of these mods make sense. The flow of LS7 chambers will be limited to the bore of the Jeep's block. Sure, a flat tappet under 230' duration @.050" should produce the same power as a roller under 230'. This is probably due to the slow and controlled closing ramps on roller cams negating the power increase from valve velocity and a loss of friction. We can go well over 230' of duration with the stock heads though. What did Newcomer have in his turbo engine 245'? Now imagine a 260 duration roller cam. Low friction, super fast valve actuation, go up to .600" valve lift and you can put as much spring pressure on that steel cam as you want. With an 80mm turbo, you would make around 1400 HP. Probably more. But would it hold a head gasket? lol
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Cheromaniac
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Re: A better cylinder head

Post by Cheromaniac »

505 Performance is the only company that continues to supply hydraulic roller cams for the Jeep I6.

https://505performance.com/shop/ols/products?page=7

Their reputation wasn't the best in the past but they still appear to be going strong.
1992 XJ 4.6 I6 - 5MT - Stroker build-up, Stroker "recipes" Sold
1995 Mustang GT - 4AT - Modded Sold
2006 Mustang GT - 5MT - Modded Midlife Crisis Car :mrgreen:
Randy Bobandi
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Re: A better cylinder head

Post by Randy Bobandi »

Cheromaniac wrote: January 3rd, 2023, 1:31 am 505 Performance is the only company that continues to supply hydraulic roller cams for the Jeep I6.

Their reputation wasn't the best in the past but they still appear to be going strong.
There is now way 505 is still doing business. Are you sure?

The "Roller" cam that they "offer" is actually a stock iron flat tappet camshaft. They tried to grind a roller profile on the stock lobes. I don't see how this could last longer than a couple hours. Too small of a base circle, and obviously, incompatible materials between the lobes and the rollers. Depending on how rowdy the profile is, It could shed enough iron to wipe out the crankshaft.
Skulljeep
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Re: A better cylinder head

Post by Skulljeep »

Cheromaniac wrote: January 3rd, 2023, 1:31 am 505 Performance is the only company that continues to supply hydraulic roller cams for the Jeep I6.

https://505performance.com/shop/ols/products?page=7

Their reputation wasn't the best in the past but they still appear to be going strong.
I recommend checking out what Rick Mudge did for the 10k rpm 4.0L top fuel motor.

https://youtube.com/playlist?list=PLP9z ... 6Ze_3CCqdj
Skulljeep
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Re: A better cylinder head

Post by Skulljeep »

I'm also going to check on the LS1 or LS6 head to see if we can get something to match up as well.
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