2.4 LD9 guide to cam swap...questions answered - Performance Forum

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2.4 LD9 guide to cam swap...questions answered
Thursday, March 29, 2012 8:22 AM
I have noticed lately there is a lot of misinformation going around about cam swapping with a 2.4 here as of late. So hopefully this will answer the questions and clear up the misinformation. I know this wont solve everything, people are too lazy to search. Anyways here goes...

FIRST AND FOREMOST if your cam swapping, then you need to have the ability to tune. Swapping in any cams with an untuned ecu will not gain much power and swapping in any cams larger than secret cams will cause a lean condition in higher RPMs that can and will damage your engine. Also tuning software can turn of the CEL from the lack of a cam sensor.

If you want to retain sequential injection instead of Batch fire injection, then you need to have a metal pad welded to your cam for the cam sensor to be able to read.

Keep in mind that to run any 2.3 intake cam and keep power steering you will need to modify the cam for the hex insert, part number 24572945 from GM. The 2.3 pump will not work with the 2.4 head.

If you choose to keep your factory springs then your cam options are:
1. Stay stock
2. Secret cams
3. 87-88 quad 4 cams (these specific years had 212 duration at 50 but only .340 intake lift and .350 exhaust lift, this was a time when there was no HO or LO)

If you are concerned that the factory valve springs aren't good enough for secret cams, they are, however if you can find a set of mantapart LD9 springs they are slightly better than stock.

To use any other cams readily available such as:
1. HO cams
2. W41 cams

You at minimum must use 2.3 HO valve springs. To do so and retain power steering you HAVE to bore out the 2.4 intake tower to accept 2.3 35mm lifters, you can use a 2.3 exhaust tower. 2.4 33mm lifters will gouge the 2.3 springs because they are wider than the lifters.

To use larger cams with more than .410 lift that are more difficult to come by but are obtainable such as:
1. HG2 cams
2. Crane cams
3. Custom ground cams

You will need better than 2.3 HO springs such as:
1. Supertech VW spring setup Click here for a how to good to .430 lift
2. People have also used springs from an LS1, but be careful to read the specs, there are many many options and some just wont work with our setup.
3. Rocket parts valve springs(hard to find)
4. Mantapart DVS (also hard to come by)


There is one other possible option for springs. This is a Crower spring Part Number 68190-16. No one has actually run this spring as of yet. They work perfectly as far as measurements on paper. It would require 2.3 retainers, 2.4 locks, and 2.4 rotators, the spring is beefy enough to handle .430 lift, but narrow enough to accept 33mm lifters without gouging. Cam tower clearance for the larger cam lobes would be needed but its cheap at a machine shop and even cheaper if you own a dremel. Some people argue that the larger cams should not be used with 33mm lifters due to failures in the past, but no one ever ran them with a proper spring either.

Hope this answers all of the questions going around that people have been asking.








Re: 2.4 LD9 guide to cam swap...questions answered
Thursday, March 29, 2012 8:36 AM
My 87 cams have 365 lift. They are originals, and also came with the original 87-88 "smooth" towers. The towers are also the steel sleeved ones. I wonder if I should send them out to have the checked?





PRND321 Till I DIE
Old Motor: 160whp & 152ft/lbs, 1/4 Mile 15.4 @88.2
M45 + LD9 + 4T40-E, GO GO GO
Re: 2.4 LD9 guide to cam swap...questions answered
Thursday, March 29, 2012 8:56 AM
-MD- Enforcer wrote:My 87 cams have 365 lift. They are originals, and also came with the original 87-88 "smooth" towers. The towers are also the steel sleeved ones. I wonder if I should send them out to have the checked?


I measured the ones I have and they were .340 and ,350 but they were originals with the smooth cam towers, odd that we have different measurements. I probably should have left them out of the write up, they are kind of a forgotten cam anyways. And according to my track times they don't make much more power than stock either.





Re: 2.4 LD9 guide to cam swap...questions answered
Thursday, March 29, 2012 10:04 AM
Re: 2.4 LD9 guide to cam swap...questions answered
Thursday, March 29, 2012 12:11 PM
good stuuf
Re: 2.4 LD9 guide to cam swap...questions answered
Thursday, March 29, 2012 6:14 PM
well you can run larger than "ho" "w41" cams with GM HO springs.... and can run on Sealed power HO springs up to 7200 rpm, you just won't get all of your power band.



Re: 2.4 LD9 guide to cam swap...questions answered
Sunday, April 01, 2012 8:44 AM
damnit. If I had only found this thread first it would've greatly shortened my own thread. Good info here...
Re: 2.4 LD9 guide to cam swap...questions answered
Sunday, April 01, 2012 3:35 PM
Well your thread and some messages in the inbox are what prompted me to make it. Just thought it would be helpful to have the info in one thread.

Kyle you are right HO springs can handle up to .430 lift but that's the limit and the valves will float as you said. It has just been recommended to use them since they are pushed to the limit, piston meet valve sucks

.



Re: 2.4 LD9 guide to cam swap...questions answered
Sunday, April 01, 2012 5:36 PM
whood mantapart LD9 springs be good to use with HO cam, if not wath is the top rpm i can go
Re: 2.4 LD9 guide to cam swap...questions answered
Sunday, April 01, 2012 7:55 PM
The mantapart LD9 springs would not be good to use with HO cams. The are slightly better than stock LD9 springs. If you can find a set of the 2.3 Mantapart dual valve springs they are the good ones. Certainly can't run stock LD9 springs with HO cams. Stock 2.3 springs at minimum are what you need to run with HO cams.



Re: 2.4 LD9 guide to cam swap...questions answered
Monday, April 02, 2012 2:40 PM
dow every 086 head have HO sping

Re: 2.4 LD9 guide to cam swap...questions answered
Monday, April 02, 2012 2:55 PM
As far as I can recall there is no HO specific spring. From what I remember every 2.3 has the same springs in it. 086 Heads can be found on HO and LO 2.3s.



Re: 2.4 LD9 guide to cam swap...questions answered
Tuesday, April 03, 2012 4:13 PM
so i can take the spring from my 086 head, and put it on my 2.4l head ?
it will be beater then the mantapart spring and safe to run my HO cam right
but i wont know if the spring will from a Lo engine
thank
Re: 2.4 LD9 guide to cam swap...questions answered
Tuesday, April 03, 2012 7:20 PM
francis chartrand wrote:so i can take the spring from my 086 head, and put it on my 2.4l head ?
it will be beater then the mantapart spring and safe to run my HO cam right
but i wont know if the spring will from a Lo engine
thank


Yes they will work on a 2.4 head but No, you cant just swap the 2.3 springs over unless you bore out the towers for 35mm lifters. As stated above the stock 2.4 lifters will gouge the spring.





Re: 2.4 LD9 guide to cam swap...questions answered
Wednesday, April 04, 2012 3:47 PM
I wish I wasn't going for shoulder surgery at 5am and could pull my heads apart and get some pics and stuff up of the springs and such. Idk why but I just can't remember how the setup looked in the two heads to see the areas that don't match up..
Re: 2.4 LD9 guide to cam swap...questions answered
Wednesday, April 04, 2012 4:01 PM
I should rephrase I suppose. All the 2.4 stuff will bolt together with the 2.3 springs, it will even run, but the edge of the lifters will ride the springs cutting into them over time, and potentially causing complete spring or lifter failure.



Re: 2.4 LD9 guide to cam swap...questions answered
Wednesday, April 04, 2012 4:05 PM
thats what I mean, it's been a bit since I've had a quad style head apart, just been too busy to have fun
Re: 2.4 LD9 guide to cam swap...questions answered
Wednesday, April 11, 2012 7:14 PM
Actually some LO LD2s had a different valve spring than the HO. Theres a post on Q4forums about it IIRC lol
Re: 2.4 LD9 guide to cam swap...questions answered
Wednesday, April 11, 2012 7:25 PM
"alright so another stupid question, to the point to where its probably right in front of me, what cars and how do you identify a 2.3HO?

"To use any other cams readily available such as: 1. HO cams 2. W41 cams"

"You at minimum must use 2.3 HO valve springs. To do so and retain power steering you HAVE to bore out the 2.4 intake tower to accept 2.3 35mm lifters, you can use a 2.3 exhaust tower. 2.4 33mm lifters will gouge the 2.3 springs because they are wider than the lifters."

so does that mean i need the lifters from said 2.3? so part list being: 1, 2.3HO valve springs. 2, lifters from said 2.3HO. 3, exhaust cam tower from said 2.3HO. 4, cams from same 2.3HO?

now the w41 cams i would still need 1-3 correct? but where do the w41 cams come from and what cams would be better w41 or HO? stupid question #129632986986: running these sets of cams would mean id run premium gasoline? but im not changing the compression... so i would still use same old 89octane?

im sorry for the zillion questions its just my motor is down to the block im changing the rods as of now and id like the reassembly to be straight forward as in not running around for parts i missed. im planning on reassembling the block one day dropping in the motor the next. washing the garage dust off the car on the third. and bringing the 94 dodge ram 1500 (better known as 1.500mpg) back to my dad."

(copied from my thread post-secret cam. Stupid question.)
Re: 2.4 LD9 guide to cam swap...questions answered
Wednesday, April 11, 2012 8:24 PM
First off i should mention that when I mention 2.3 I am completely disregarding the 95 2.3. It has many parts that are like the 2.4.

To run HO or W41 cams you will need 2.3 springs and retainers, 2.3 lifters, 2.3 exhaust cam tower, and have your 2.4 intake bored out for the 2.3 lifters. Also the hex insert installed into the intake cam. HO cams come in cars that have a D in the vin and can be found in a scrap yard somewhat easily. W41 cams are slightly bigger with 7* more duration but are harder to come by. They are easy to get if you want to spend the money for them, you can probably find a set on quad4forums.

Hope that helped



Re: 2.4 LD9 guide to cam swap...questions answered
Wednesday, April 11, 2012 9:32 PM
What type of cars do you know? Like years and such. And is it the 8th digit that a "D?"

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