porting a head for a stock 4.0 ????????????

[Flash]

So are ya happy with the renix porting?????? or will ya be using one of the HO heads when ya go back to gether with the stroker?

Have ya done any of the ether mod like larger throttle body,space, adj map sensor?


Flash.

 

[XJING]

So are ya happy with the renix porting?????? or will ya be using one of the HO heads when ya go back to gether with the stroker?

Have ya done any of the ether mod like larger throttle body,space, adj map sensor?


Flash.

I plan on using the renix head, my bored Renix TB at 59.5, I have had made a spacer to go from my Renix TB to a 99 head I picked up, but dont know if I will use it, (most will say why dont you go with a HO TB, I am just toying with the idea of keeping the TB Renix, and if not, seeing if the '99 intake will fit, and going HO TB from there) Picked up the same cam Dino runs, got a 12 weight crank, gonna bore it out .60, balanced rotating assembly, pistons, rods, crank, Have most of the external mods, Going with a "true cowl" induction set up that I have been working on for some time. Besides bearings and gaskets thats about it.

 

[SCW]

I plan on using the renix head, my bored Renix TB at 59.5, I have had made a spacer to go from my Renix TB to a 99 head I picked up, but dont know if I will use it, (most will say why dont you go with a HO TB, I am just toying with the idea of keeping the TB Renix, and if not, seeing if the '99 intake will fit, and going HO TB from there) Picked up the same cam Dino runs, got a 12 weight crank, gonna bore it out .60, balanced rotating assembly, pistons, rods, crank, Have most of the external mods, Going with a "true cowl" induction set up that I have been working on for some time. Besides bearings and gaskets thats about it.

Are you aware that the good doctor is now running a stock 4.0 cam due to cam failure? There has been a lot of good conversation on the Yahoo! strokers group about cams. It would probably be in your best interest to check up on it before you build your beast.

 

[XJING]

Are you aware that the good doctor is now running a stock 4.0 cam due to cam failure? There has been a lot of good conversation on the Yahoo! strokers group about cams. It would probably be in your best interest to check up on it before you build your beast.

No I wasn't aware of that, I have the cam already, but will definitley be looking into that,,, Thanks for looking out!
I appreaciate it.

 

[Dr. Dyno]

Yup, the no.6 intake lobe on my Crane 753905 went flat after 34000 miles, and the no.6 intake lifter was worn concave. It probably stopped rotating in its bore. Don't know why but it's been suggested that synthetic oil is to blame. I'm not sure I buy that though.
Use the stock valve springs for the cam break-in and use mineral oil ALL the time. Rotella T still has enough ZDDP to protect the cam so it might make a difference. I wish I knew that earlier!
Anyway, even with the stock cam I'm getting 210hp and 250lbft to the rear wheels so the Jeep's not exactly a slouch.

 

[Flash]

Yup, the no.6 intake lobe on my Crane 753905 went flat after 34000 miles, and the no.6 intake lifter was worn concave. It probably stopped rotating in its bore. Don't know why but it's been suggested that synthetic oil is to blame. I'm not sure I buy that though.
Use the stock valve springs for the cam break-in and use mineral oil ALL the time. Rotella T still has enough ZDDP to protect the cam so it might make a difference. I wish I knew that earlier!
Anyway, even with the stock cam I'm getting 210hp and 250lbft to the rear wheels so the Jeep's not exactly a slouch.

Any chance of ya going back to a bigger cam/valve springs........any time ??????


flash.

 

[Dr. Dyno]

Not in the foreseeable future unless my stock cam decides to crap the bed as well. Fingers crossed, that won't happen. I actually like the extra low rev torque of the stock cam and I've only lost 2/10ths of a second to the 1/4 mile, so my Jeep will still do a 14.7@94 in full street trim. The engine pulls smoothly to 5250rpm with ease now that I've got rid of the JET Stage 2 POC.

 

[Flash]

Not in the foreseeable future unless my stock cam decides to crap the bed as well. Fingers crossed, that won't happen. I actually like the extra low rev torque of the stock cam and I've only lost 2/10ths of a second to the 1/4 mile, so my Jeep will still do a 14.7@94 in full street trim. The engine pulls smoothly to 5250rpm with ease now that I've got rid of the JET Stage 2 POC.

So what oil are ya choosing to us with your stock cam.

2/10 is not enough to wary to much about.

Has the fuel economy changed much!

Flash.

 

[Dr. Dyno]

Gas mileage is unchanged and I'm using an SL-rated 10W-40 semi synthetic oil made in the UAE by ADNOC (Abu Dhabi National Oil Company).

 

[Pro Stock John]

Interesting thread. I don't plan to do any engine mods to my 95 XJ but I have other cars that are modded (98 Formula, 8:1, turbocharged, 867rwhp), but if I did mess with it I'd probably port the head, do beefier springs, and look into rockers.

 

[Flash]

Interesting thread. I don't plan to do any engine mods to my 95 XJ but I have other cars that are modded (98 Formula, 8:1, turbocharged, 867rwhp), but if I did mess with it I'd probably port the head, do beefier springs, and look into rockers.

Until these "cam failed' settle down............that would be vary scary!!!!


Flash.

 

[Pro Stock John]

Could be lifter preload issues...?

 

[Flash]

Could be lifter preload issues...?

Yup, there is many places to to point blame AND, I think, that every one of these have a piece of the pie, that make the problem!!!!!!!! lifter Quality,spring pressure improper brake in of the new cam, valve train out of tolerance(not in spec.) and the "WONDER FULL new recipe" that has been forced a ponded are favorite brand of OIL!!!!


Only time will tell how far spread the cam fail will spread if it is the oil!!!!!!


Flash.

 

[Pro Stock John]

I've never broken in a new cam. I wonder what the lifter from that cylinder looked like.

 

[MudDawg]

If you check the websites of any cam manufacturer, they ALL have warnings about oil...I have been building engines for the best part of 35 years...and the one thing I have learned is nothing remains the same....for example the old leaded gas we used to have that was so good at controlling detonation is out the window because of the environmental impact....now its the heavy metals in oil that protect the wear areas in flat tappet cams...the reality is in this age, most everything uses roller lifters as OEM....roller lifters are not affected adversely by modern "green" oils.

Another issue that may be a major contributor is extended idle times especially during cold weather engine warm up...the lifter/lobe interface is lubricated by splash....long idle times=poor cam lobe lubrication. Add in high valve spring pressures and the problem is compounded....and just for grins...toss in fast lobe ramp rates....I know this does not cover all the possible failure scenarios, but it does cover a sizeable percentage...

 

[Flash]

If you check the websites of any cam manufacturer, they ALL have warnings about oil...I have been building engines for the best part of 35 years...and the one thing I have learned is nothing remains the same....for example the old leaded gas we used to have that was so good at controlling detonation is out the window because of the environmental impact....now its the heavy metals in oil that protect the wear areas in flat tappet cams...the reality is in this age, most everything uses roller lifters as OEM....roller lifters are not affected adversely by modern "green" oils.

Another issue that may be a major contributor is extended idle times especially during cold weather engine warm up...the lifter/lobe interface is lubricated by splash....long idle times=poor cam lobe lubrication. Add in high valve spring pressures and the problem is compounded....and just for grins...toss in fast lobe ramp rates....I know this does not cover all the possible failure scenarios, but it does cover a sizeable percentage...

I couldn't agree more!!!!!!!!

no lead = hardened ex valve seats

As you put it the heavy metals in oil has been removed! = ..........Even harder lifter faces???????????

WOULD SOME ON .....:idea: .PLEASE! BUILD A HYD ROLLER LIFTER FOR US:idea:


I SAID PLEASE

Flash.

 

[Slo-Sho]

I agree a roller cam for the I6 application would be a major step forward towards performance. There is one thing though, How would the roller lifter stay oriented in the correct position being that far apart from any either adjacent lifter? The only roller lifters I've ever seen are paired together to stay lined up.

 

[Flash]

I agree a roller cam for the I6 application would be a major step forward towards performance. There is one thing though, How would the roller lifter stay oriented in the correct position being that far apart from any either adjacent lifter? The only roller lifters I've ever seen are paired together to stay lined up.

Well the lifter bore is the same as a Chry V8 and LUNATI now make them for the Chry(non roller) eng, so the lifter is avalible...........just as ya say "how do ya keep it oriented?'

5-90 sound like he has a good idea on it He just don't have the time to dedicate to it......................so, don't give up hope...........but don't hold your breath eater.
There is so many grate possibility to these 4.0 (AMC/ Chry I-6 In general!) with a ROLLER Hyd lifter.:sunshine:

Flash.

 

[Pro Stock John]

If only one lobe got messed up it points to a valvetrain issue, not a cam grind issue.

 

[Flash]

If only one lobe got messed up it points to a valvetrain issue, not a cam grind issue.

Unless that lifter was not heat treated corectly! I read a arctice that......some one sent me were crane was testing there lifters for just that reason.

Don't get me wrong i agree, just that this ^ could be related also! Just one bum lifter could make for a bad day!


flash.