lifters

[turbo addict]

OK here is the deal, I am doing springs and retainers in my DD and it has the original jdm lifters. I can remember but would bet that they are the old style, but I have never had any problems with them no noise or anything. I have jun 264 cams now and my rev limit is at 7800rpm however I plan on upping it to 8800 or 9000rpm with the springs and retainers. What do you all think and why?
The motor has the jdm 30,000-40,000miles plus 15,000 from me= (hard) miles.

 

[dsm-onster]

I don't understand your profile. . .everything runs together. Which car are you wanting to raise the rev limit on?

I see a 1995: with an evo3 16g, you'll be hard pressed to get it to hold high boost to the stock revlimit.

264s seam to work fine to stock redline. I've never heard of any gains from taking them beyond this. My fp2xs (like 272s w/ more ramp rate) like 7500 just fine. I've run to 8500 w/out feeling a loss though.

What intake manifold for this DD do you have?

What springs and retainers? double springs and titanium retainers should get you there w/ no ill effect on themselves. But when revving to 9K, I'd take a look at solid piece SS valves.

 

[turbo addict]

Sorry kind of ran out of room, My dd is a 1989 mirage turbo, I have a e316g on it and it is still a 4g61t (1.6L) I have a fp exhaust mani, and a forrester intake mani on the way now, I also have a set of supertech single springs and a evo8 mas and 850 injectors, I am going to use the e316g for now and next winter change to the bb60trim that is on my talon (98) currently.
With the 2g exhaust manifold and cyclone dr intake and the e316g I run 20-22psi on pump and 32psi on 110leaded, power does not fall off to 7800rpm I am going to clean up my engine bay and get rid of the cyclone intake manifold.

There is also a possibility of upgrading my cams to either the bc 272 or fp2 but that would be with the turbo swap next winter.

I have too darn many projects and it is killing me! 1995 tsiawd (drag car) mirage turbo (DD) 1998 tsiawd (my baby 6008miles on her) a gvr4 and a 1993 pulsar gtir (RHD a friends project I picked up when he married)

 

[dsm-onster]

Ok. There's no need to run over 7000 rpms w/ 264 intake duration due to ram effect (air is elastic) and other more complicated considerations.

With the 2g exhaust manifold and cyclone dr intake and the e316g I run 20-22psi on pump and 32psi on 110leaded, power does not fall off to 7800rpm

That's too hard for me to believe. And I usually like the thoughts that go out side of the box. I know that you have a small engine. But 264 intakce duration cams will not flow well enough up at 7800 rpms to even feel like it's not losing breath. Get a dyno graph so that we can help you out better. Knowing your power band is key to picking you head components. . .

 

[hereitcomes]

And if your on the stock lower end that wont last long. Rev's kill cars not power.

 

[dsm-onster]

You'll need ARP rodd bolts at least. I'm not sure what rpm 6 bolt rods have gone. And you have smaller 7 bolt rods. . . I don't know. . . There's alot more forces acting on the piston rod other than the downward pressure from combustion.

 

[2gAWDTalon]

I have spun my stock 6 bolt rods with stock bolts to 8500 daily and a few 9K shifts. This was above 500 awhp. Never had a problem in 4K miles. Pulled motor and sold it just because my power level was pushing the stock rods.

 

[2gAWDTalon]

I just thought about it and that is not fair, I did not give the whole story. It was a fresh rebuilt 6 bolt, stock crank, stock rods, wiesco pistons. Everything was check and gone through at a machine shop, rods were shot peened. Motor was assembled with all new bearings. So it was a fresh rebuild...
But it was on stock rods with stock rod bolts whitch I belive were in question above.

 

[dsm-onster]

Yea, no matter what you did this w/ stock rod bolts! that's great and another "1 up" for the 6-bolt block. . . I'm so glad to have bought a 1990 .

So would it be your suggestion be not to push it past 8500 rpms. I'm running to 8500 rpms on a DD as well. BUT I don't do it often because I was leary of the rod bolts holding for long. I was tempted just to get arp hardware, but keeping my foot out of it is more affordable . And I have a new baby on the way.

turbo addict, what are your HP goals? It seams that most guys reach 500 hp before 8500 rpms w/ decent cams, smim, proper turbo, and a big intercooler which would be the maximum safe limit of the 6-bolt according to the common consensus.

 

[turbo addict]

Yea, no matter what you did this w/ stock rod bolts! that's great and another "1 up" for the 6-bolt block. . . I'm so glad to have bought a 1990 .

So would it be your suggestion be not to push it past 8500 rpms. I'm running to 8500 rpms on a DD as well. BUT I don't do it often because I was leary of the rod bolts holding for long. I was tempted just to get arp hardware, but keeping my foot out of it is more affordable . And I have a new baby on the way.

turbo addict, what are your HP goals? It seams that most guys reach 500 hp before 8500 rpms w/ decent cams, smim, proper turbo, and a big intercooler which would be the maximum safe limit of the 6-bolt according to the common consensus.

Max power I would ever need is 400 to maybe, almost, 450hp dynojet with the 60trim and bigger cams.
My motor is a 6bolt and stress is not that bad on a 4g61t as it is only a 75mm stroke.
(Stroke (in inches)X Max RPM )/6= piston speed in feet per second

88 MM
(3.4646" x 7500)/6 = 4330.6 feet per min

the 4g61t is a 75mm stroke in my mirage turbo.
(2.9527x7500)/6=3690.944 feet per min.
(2.9527x8500)/6=4182.991 feet per min.
(2.9527x9500)/6=4675.108 feet per min.
and rod to stroke is 5.9/2.9527=1.9981
As you can see the piston speed in lower on the mirage (1.6l) at 8500rpm than the eclipse (2.0L) at 7500. which is why I was going to rev her alittle.
I also am not sure going to 272's will be that great of an upgrade as the jun are known to be a very aggressive cam for there rated duration. Again any thoughts or ideas are very welcome!

 

[dsm-onster]

Max power I would ever need is 400 to maybe, almost, 450hp dynojet with the 60trim and bigger cams.
My motor is a 6bolt and stress is not that bad on a 4g61t as it is only a 75mm stroke.
(Stroke (in inches)X Max RPM )/6= piston speed in feet per second

88 MM
(3.4646" x 7500)/6 = 4330.6 feet per min

the 4g61t is a 75mm stroke in my mirage turbo.
(2.9527x7500)/6=3690.944 feet per min.
(2.9527x8500)/6=4182.991 feet per min.
(2.9527x9500)/6=4675.108 feet per min.
and rod to stroke is 5.9/2.9527=1.9981
As you can see the piston speed in lower on the mirage (1.6l) at 8500rpm than the eclipse (2.0L) at 7500. which is why I was going to rev her alittle.
I also am not sure going to 272's will be that great of an upgrade as the jun are known to be a very aggressive cam for there rated duration. Again any thoughts or ideas are very welcome!

Well, do you have "6-bolt style" rods in your 4g61?



'Aggressive for their rated duration' tells me that they have higher ramp rates and good lift. Great for torque and horspower at their optimum rpm level. But it tells me nothing about rpm range for peak power. The duration tells me that. Are both cam grinds biased toward the top end by retard, or do they exibit very low overlap? The latter is not likely.

No matter what, 272s will be better for high rpms than 264s. The duration w/ the proper cam degreeing is what delivers best results. 264 advertised duration is better where cam timing is tuned for the midrange: 3K-6K. If you tune the 264s w/ cam timing for 7K+ then you're choking the airflow. The air NEEDs the intake cam to open longer because it is "elastic" and "rams" in during the intake stroke. Thus shutting off the intake charge early by closing the valve earlier because of lower duration or open (time) negates the benefit of any tune up top. Pick the right duration for the rpm. 264s are NOT the right duration for your proposed application.

 

[turbo addict]

Well, do you have "6-bolt style" rods in your 4g61?



'Aggressive for their rated duration' tells me that they have higher ramp rates and good lift. Great for torque and horspower at their optimum rpm level. But it tells me nothing about rpm range for peak power. The duration tells me that. Are both cam grinds biased toward the top end by retard, or do they exibit very low overlap? The latter is not likely.

No matter what, 272s will be better for high rpms than 264s. The duration w/ the proper cam degreeing is what delivers best results. 264 advertised duration is better where cam timing is tuned for the midrange: 3K-6K. If you tune the 264s w/ cam timing for 7K+ then you're choking the airflow. The air NEEDs the intake cam to open longer because it is "elastic" and "rams" in during the intake stroke. Thus shutting off the intake charge early by closing the valve earlier because of lower duration or open (time) negates the benefit of any tune up top. Pick the right duration for the rpm. 264s are NOT the right duration for your proposed application.

The cams are not all the same just because they are rated at 264 adv. duration, a lot of the cam manufactures rate at different points which was why I wasn't sure about the upgrade, I have read that the evo guys are making more topend power with the 272juns than on the HK$280s.
And the fact that my power doesn't drop off at 7800rpm, or that the kid I bought them from was running a 1ga with a 20g up to 8200rpm and went to fp2x and didn't make a huge difference (airflow was very close) . But I also realize that part of it could be that he was out of turbo.

I am curious of anyone that has had personal experience with juns.
Also my mirage is a turbo from the factory (1989) so the 6bolts are the exact same that are in the 6bolt eclipse.

I am not trying to argue just curious why it pulls so well.

 

[dsm-onster]

The cams are not all the same just because they are rated at 264 adv. duration, a lot of the cam manufactures rate at different points which was why I wasn't sure about the upgrade, I have read that the evo guys are making more topend power with the 272juns than on the HK$280s.

Agreed. This is why knowing the .05" lift duration is a good idea. . . Do your research.

Cam shape is not really a black art. ASSuming they both have zero lift advertized duration, and not drastic enough ramp rate to require a spring upgrade, AND they share similar overlap characteristics; THEN duration is king. Get a cam card or the manufactures specs. Otherwise we're bench racing .

And the fact that my power doesn't drop off at 7800rpm, or that the kid I bought them from was running a 1ga with a 20g up to 8200rpm and went to fp2x and didn't make a huge difference (airflow was very close) . But I also realize that part of it could be that he was out of turbo.

If he was running a TD05H 20g then this is likely and possibly why he felt no difference. I have zero experience w/ JUN 264s. But, my FP2Xs want more than 8500 rpms w/ my RS60 and a stock intake that wants to sh!t out at 6500 rpms according to the intake manifold test done a few years back.

I am curious of anyone that has had personal experience with juns.
Also my mirage is a turbo from the factory (1989) so the 6bolts are the exact same that are in the 6bolt eclipse.

I am not trying to argue just curious why it pulls so well.

Then you're good if that's the case. Let her rip.

 

[wvturbo2]

Jun 264's and Jun 272's are meaty cams. The 264 and 272 means nothing they are just numbers. You need to look at lift and duration. Their lift and duration are higher than other "264" and "272" cams. Don't assume they are the same as your fp, hks, bc cams. The Jun 272's were used on a 1000 + hp evo If that helps to prove my point a little better. I still wouldn't rev above 8 grand. See where the power drops off then stop reving. 9k Is overkill.

 

[dsm-onster]

Ok. So 264 is just a number and has nothing to do w/ duratioin at all. Like i said i do not profess to know anything about JUN cams. I still stand by my recommendation to go w/ the higher duration cams; which noone here seams to be disquailifying .

9K is not overkill if the duration and cam timing allows high VE at 9K. This guy hasn't mentioned HP goals. So I'm assuming he's done a little homework and knows that volume he has to dispace over time (rpm) to reach the goal he wants. If the jun 264s fall off at 8K then it is highly likely that the FP2Xs have MUCH more duration than JUN 264s. If JUN 264s fall off at 8K then they are not proper for the original poster's goal.

turbo addict, dyno the cams. Or, better yet, get a good log of the airflow in lbs/min from 2K to 7.5K; and, from there, we can calculate your VE based on your engine volume. Where your VE starts dropping, you've got your upper end of powerband for your particular cam grind. Or, get the cam specs and report back here.

BTW, you'll need a good SMIM.

 

[turbo addict]

Ok. So 264 is just a number and has nothing to do w/ duratioin at all. Like i said i do not profess to know anything about JUN cams. I still stand by my recommendation to go w/ the higher duration cams; which noone here seams to be disquailifying .

9K is not overkill if the duration and cam timing allows high VE at 9K. This guy hasn't mentioned HP goals. So I'm assuming he's done a little homework and knows that volume he has to dispace over time (rpm) to reach the goal he wants. If the jun 264s fall off at 8K then it is highly likely that the FP2Xs have MUCH more duration than JUN 264s. If JUN 264s fall off at 8K then they are not proper for the original poster's goal.

turbo addict, dyno the cams. Or, better yet, get a good log of the airflow in lbs/min from 2K to 7.5K; and, from there, we can calculate your VE based on your engine volume. Where your VE starts dropping, you've got your upper end of powerband for your particular cam grind. Or, get the cam specs and report back here.

BTW, you'll need a good SMIM.

I am going to take the engine to the machine shop this week to get it cleaned up and the exhaust main. stud fixed so I hope within a 2-3weeks everything will be back on and ready to go. I will try to get some logs as soon as it is running again.
I have a forrester intake manifold and a fp exhaust manifold going on with the e316g for now, so I will how everything works together.