383 heads and cam swap questions

[XH29N0G]

I have a 70 Charger with a 383/4 speed and 4.30 rear.  It has a Performer RPM intake with a Holley 670 vacuum secondary carburetor and headers.  Bottom part of engine is stock.  Factory spec at 9.5 compression.  Cylinder pressure around 135 psi.  I would like to install Edelbrock Performer RPM cylinder heads and a new cam.  I do not plan to port the heads.  I will drive the car on the street, but it is not a daily driver.

I am new to this and have a bunch of questions.  I will be happy if I can get answers for any of them.

1) Can you recommend whether I can buy the complete heads with springs and valves and use them as is, or whether it would be better to install springs recommended by the companies that make the cams?

2) Can you provide a recommendation of a cam for me.  I am thinking that the engine will see between 5500 and 6000 rpm.  I am thinking about the following Cams

Lunati 60301/60302
Comp Cams XE262H/XE268H
Engel K54

3) I have Hooker Comp Plus headers and understand I will need to dent them. For plug clearance.  Any advice on how to do this?

4) Can provide comments on other things that I should change (push rods, rocker arms)?  I am assuming I change the timing chain and am looking at one like that from Comp Cams (2104 or 2109).    

5) Am I likely to run into any surprises changing the cam with the engine in the car.  

Thank you

[MORFF]

James I can not answer your question but the guys on hear always helped me out. I have a question for you  I am looking at a 383 big block this weekend that came out of a 69 charger and its going in my 69 charger. Was your 383 big block with a 4 speed factory or did you have to get after market kit for the tranny? Thanks james

[XH29N0G]

The car came from the factory with a three speed, a floor shifter and a bench seat.  It was my parent's family car.  In the early 1980's I traded a manifold for the 4 speed (OD unit) and put it in. 

In the next few years, I am planning to do much more with this car, restoring the body and having more work done. As part of that, I am considering changing the transmission to an aftermarket transmission, but I want to do the changes to the heads and cam first.

 

[XH29N0G]

An update: 

I called the technical support line at Lunati and the person I spoke with answered some of my questions.  He said (1) the stock rocker arms should work, and (2) that the complete heads would be fine, but I should check with Edelbrock about the specs on the valve springs (what was needed was more than 110 lb closed/300-320 lb open).  This is similar to what I see in the Edelbrock literature, but I will call them tomorrow because their tech line was busy on Friday. 

He also suggested a 60303 cam, which I wonder if it is a little large given what I have seen discussed on the lists.  Any thoughts on this? 

James

[c00nhunterjoe]

For a stock cam, a 135 psi comp reading sounds low, but assuming you bottom end is solid I would suggest calling either comp cams or isky. They are my top 2 picks for cams. Iskys tech support is top notch. Tell them exactly what you want your car to do and how you want it to drive and they will get you the correct cam. We could all give you suggestions that will be in your ballpark.

I will suggest a solid cam. With similar specs to its hydraulic counterpart you will make more power, have better engine vaccum, and a milder idle.  Bear in mind you will have to buy adjustable rockers. I will reccomend the comp xs282s. Its a nice mild solid cam that will work great with the rpm heads. If you look at the flow numbers on the heads they will make the best power nearing 550 lift. You will also see the exhaust side is lacking flow. This will benefit from a split grind cam. The cam I listed will fit the bill and
Make great power at a reliable and usable rpm that will give you a low maintenance, turn-key driver.

Any cam swap denotes checking your pushrod length, most likely you will get new ones.

The complete heads are the best bang for the buck, but as lunati said, check your cam specs to see if the springs will work.

Your carb needs to go, swap it out for a nice 750 dp, mechanical secondaries and you will see a big difference in the car from that alone..

[Budnicks]

If your going to just be mainly a street driven/mostly, maybe it might be a better idea is to go to the new E-Street 440 Edelbrock 75cc combustion chamber 291cfm int/217cfm ext. flow @ 0.600" lift 1.55" valve springs, 11/32" 2.14"int/1.81"ext. valves, E-Street 440 aluminum heads they are very simaliar to the RPM's in design & flow #'s they are rated to 5500rpms with stock components & they are cheaper {also use cheaper valvetrain componenets, to keep costs low}, but have 9cc-13cc smaller combustion chambers {compaired to 84cc-88cc RPM's}for more compression & you will need to change the valve springs, retainer & locks too possibly/probably for your specific camshaft, I believe that they are straight plug design heads too {not absolutely sure}... Go to www.edelbrock.com website & check out the specs, maybe even just call them, to make sure of spring pressures & angle or straight plug design... I haven't seen a set in person yet, just read about them, if they are anything like the RPM's you will be happy with the performance & workmanship, all American made products...

[c00nhunterjoe]

A 9.5:1 motor is great for a cruiser on pump gas. If you want to step it up a little then run the 84cc heads and get around 10:1. Valvetrain is the last place to cut corners, especially if you want a reliable cruiser.

What are those new heads flowing at .500?

[Budnicks]

A 9.5:1 motor is great for a cruiser on pump gas. If you want to step it up a little then run the 84cc heads and get around 10:1. Valvetrain is the last place to cut corners, especially if you want a reliable cruiser.

What are those new heads flowing at .500?

They say 278cfm int./206cfm ext. @ 0.500" valve lift go to www.edelbrock.com/ to see flow #'s & specs for yourself...

[firefighter3931]

I would use the 84cc RPM heads and the Lunati #302 cam. I specced a similar 383 build for another member using that cam and its a tire fryer  Awesome off idle throttle response and descent manifold vaccum for easy tuning. 

Check out Jackson's video in the thread below for a nice burnout & full throttle blast. 

http://www.dodgecharger.com/forum/index.php/topic,78094.0.html


Ron

[Budnicks]

I used the Eddy 84cc RPM's on my personal 383 build also,   I just wanted to throw out the less expensive option for mainly street cars of the new Edelbrock E-Street w/75cc combustion chamber, they looked promising for the $979 per/pr. price, same style ports & valve sizes as the RPM's, {I think this is their attempt to get the customers over from Stealth price range} especially if your just using a stock bottom end with low compression pistons & going to do some porting or replace the springs, retainers & lock anyway, why pay the extra $500 for the RPM's....    I haven't seen them in person or used them yet, I was told about them by a very trusted professional engine builder/head porter

[firefighter3931]

The 75cc E-heads aren't even in production yet so there might not be anything available until the summer.    I wonder if that pricing is infact correct ; Summit shows the 84cc E-Street heads at $50 less than a set of Rpm's  We'll see how much they end up selling for once they hit the market

With 9.5 compression the 84cc heads will work just fine and still keep him in "pump gas" territory 

I do think the 75cc heads will be a hit with the guys that have low compression shortblocks that need a boost in compression. One thing that will need some checking is the bore shrouding. Oversize 2.14/1.81 valves with a small 383 (4.25in) bore can create clearance issues....best to check 



Ron

[XH29N0G]

Thank you for these replies.  These will help me a lot.  I have a few quick questions.

Do the RPM heads have an issue with valve size and the 383 bore as is suggested will need to be checked with 75cc E streets that may be released?  I am assuming not, but if they do, it will be important for me to know.  

I am assuming I measure the pushrod lengths after getting the cam and lifters and heads installed, or is there information on the specific push rods that would be good with a 60302/Eddy RPM combination with stock rocker arms?

Finally, I am assuming I will figure out how to dent my headers if needed? and if that does not work to change to TTI.  Any experience on what tools people have used successfully/unsuccessfully would be appreciated.

[firefighter3931]

Thank you for these replies.  These will help me a lot.  I have a few quick questions.

Do the RPM heads have an issue with valve size and the 383 bore as is suggested will need to be checked with 75cc E streets that may be released?  I am assuming not, but if they do, it will be important for me to know. 

I am assuming I measure the pushrod lengths after getting the cam and lifters and heads installed, or is there information on the specific push rods that would be good with a 60302/Eddy RPM combination with stock rocker arms?

Finally, I am assuming I will figure out how to dent my headers if needed? and if that does not work to change to TTI.  Any experience on what tools people have used successfully/unsuccessfully would be appreciated.

James

James, the RPM heads will be a bolt on deal here....the valvesprings/retainers/locks will all be fine with the #302 VooDoo cam. I would recommend having a shop go over them for a quick check and have them look at the valve guide clearance. On occasion a few might be tight and need a quick pass with the hone to open them up a thou or two. 

If your rocker arms are in good shape you can reuse them but i will recommend a quality 5/16 chrome moly pushrod as an upgrade. Mancini has them for ~$75. The Comp Cams "Magnum" double roller chain is all you need. You need to order a 3 bolt upper gear timing set to match the Lunati cam.

As for the shrouding issue ; i don't see that as a problem with the #302 cam because it has less than .500 valve lift. Bigger cams with higher ratio rocker arms create some issues but not in your case.

Denting headers for clearance isn't that difficult. Use a torch to heat up the pipe and place an impact socket on the area you want to dent. Hit the socket with a hammer and bingo...instant clearance. Using the socket will give you a nice radiused clearance pocket and won't impede flow significantly.



Ron

[Budnicks]

The 75cc E-heads aren't even in production yet so there might not be anything available until the summer.    I wonder if that pricing is infact correct ; Summit shows the 84cc E-Street heads at $50 less than a set of Rpm's  We'll see how much they end up selling for once they hit the market

With 9.5 compression the 84cc heads will work just fine and still keep him in "pump gas" territory 

I do think the 75cc heads will be a hit with the guys that have low compression shortblocks that need a boost in compression. One thing that will need some checking is the bore shrouding. Oversize 2.14/1.81 valves with a small 383 (4.25in) bore can create clearance issues....best to check 



Ron

Firefighter your 100% correct... I saw that also in the Jegs advertisement & asked the same question, I was also under the impression they were out already, What I was told by a friend who is pretty spot on on this stuff most all of the time, said the 75cc version is the $979 & the 84cc version is $1470+ "I'm not sure if that is correct or not" {I am on the phone with Edelbrock tech. as I'm here waiting}, but I do trust the guy who told me... The 2.14"/1.81" intake valves will clear the tops of the cylinders, but some very slight notching/beveling in the immediate effected area is recommended for better flow, with out any valve shrouding problem... I called the source Edelbrock them selves, they said "They are the same port as the RPM", the 84cc versions are available now,  the 75cc is in delvelopment, some extra machining needed to be done, that caused a delay & will they will be out in arround 60 days & that price will be more like the RPM's not the $980 range, the only person I could talk to said " but there isn't a price on the 75cc head as of yet"... I suggested to him that it would be a very good idea to price them at the level of the Stealth heads that are $980 range... So I would guess the price that was said earlier will be much higher, after talking to the Edelbrock tech. rep., to bad-so sad, I'm profoundly sorry for any confusion I may have caused over the pricing, I will contact my cylinder head/porter friend & set him straight...

[XH29N0G]

Hi All,

A quick question.  I decided to make the changes in steps.  Change the heads first, make sure I understand how it is working and then change the cam (which I will do in the next week or two).  

With the change in heads, I think I repaired a slightly leaking head gasket. [The compression in the # 8 was a little low (120 -125 psi instead of 135 psi which the other cylinders were) and the piston was much cleaner (no carbon buildup) compared to the other pistons.]  It is now at 140 PSI and that is where the others are.

With the change to the Eddy heads, I noticed a change in manifold vacuum at idle 20 inches instead of 18, but there is now a slight hesitation and backfire on accelleration from 1500 RPM.  

The Question: Could changing the heads and fixing the #8 cylinder mean that I have to adjust my carburator?  Should I do this before changing the cam?  

The car has a vacuum secondary Holley Avenger 670 and a performer RPM intake and heads.  When these were first installed there was hesitation, backfire, and surging that were eliminated by increasing the nozzle to an 035 and changing to a blue cam (1st hole) and by increasing the jet sizes by 3 and 2 (primary/secondary).  

Any feedback will be greatly appreciated.

[heyoldguy]

The 75cc E-heads aren't even in production yet so there might not be anything available until the summer.    I wonder if that pricing is infact correct ; Summit shows the 84cc E-Street heads at $50 less than a set of Rpm's   We'll see how much they end up selling for once they hit the market

With 9.5 compression the 84cc heads will work just fine and still keep him in "pump gas" territory  

I do think the 75cc heads will be a hit with the guys that have low compression shortblocks that need a boost in compression. One thing that will need some checking is the bore shrouding. Oversize 2.14/1.81 valves with a small 383 (4.25in) bore can create clearance issues....best to check  



Ron

Firefighter your 100% correct... I saw that also in the Jegs advertisement & asked the same question, I was also under the impression they were out already, What I was told by a friend who is pretty spot on on this stuff most all of the time, said the 75cc version is the $979 & the 84cc version is $1470+ "I'm not sure if that is correct or not" {I am on the phone with Edelbrock tech. as I'm here waiting}, but I do trust the guy who told me... The 2.14"/1.81" intake valves will clear the tops of the cylinders, but some very slight notching/beveling in the immediate effected area is recommended for better flow, with out any valve shrouding problem... I called the source Edelbrock them selves, they said "They are the same port as the RPM", the 84cc versions are available now,  the 75cc is in delvelopment, some extra machining needed to be done, that caused a delay & will they will be out in arround 60 days & that price will be more like the RPM's not the $980 range, the only person I could talk to said " but there isn't a price on the 75cc head as of yet"... I suggested to him that it would be a very good idea to price them at the level of the Stealth heads that are $980 range... So I would guess the price that was said earlier will be much higher, after talking to the Edelbrock tech. rep., to bad-so sad, I'm profoundly sorry for any confusion I may have caused over the pricing, I will contact my cylinder head/porter friend & set him straight...

Budnicks yer dah man, but you ain't settin' me straight. If you call Summit Racing and order the 5090 heads now, you will get them for $979.95 WHEN Summit takes delivery from Edelbrock. I just called Summit and asked them. They gotta bunch of 'em on order. I am gunna get one of the heads, put on the flowbench in stock form, then port it and reflow it......Jim

[heal0048]

I expect you will have to make more carb adjustments after the cam... just like after the heads.  Needs more fuel and quicker.

Did you see where your pistons sit relative to the deck when you had the heads off?  My 383 is only 8:1 with the pistons .080" below and .020" head gaskets.  The motor had the Comp Xtreme 268 and I would NOT recommend this cam for your application.  It was ok, but you could do much better.  I went with the Hughes Whiplash and the results are much better - although not enough vacuum for power brakes.  This might not be the best cam for your setup either; however, I would verify your compression ratio before you select a cam.

[XH29N0G]

Unfortunately I did not verify how far down the pistons sit, and I already have the cam I intend to try (the Lunati 60302). 

The bottom is original, and my guess is that it cannot be that far from the original compression which was advertized at 9.5:1.  While I read somewhere that compression does not relate to cylinder pressure, the 140 PSI I measure divided by the ~14.7 PSI of the atmosphere is also close to 9.5:1.  Does someone have more insight into this.  I also think the compression will not change much with the head change because the thicker Felpro gasket and slighly smaller 84cc combustion chambers of the eddy heads would compensate for the original gaskets and the 87-89cc 906 heads that were in it before. 

Thank you also for making your recent post on your car.  It is an interesting read.

I have another question.  After the install of the cam, it has to be broken in at 2000 + RPM.  Is there a reason not to set the idle screw on the carb at 2000 rpm just before I shut it down for the install?

[Chryco Psycho]

most cams recommend to be broken in in the 1800-2000 range at steady speed , you can set the carb up , you will be close when you refire it

[Budnicks]

The 75cc E-heads aren't even in production yet so there might not be anything available until the summer.    I wonder if that pricing is infact correct ; Summit shows the 84cc E-Street heads at $50 less than a set of Rpm's   We'll see how much they end up selling for once they hit the market

With 9.5 compression the 84cc heads will work just fine and still keep him in "pump gas" territory  

I do think the 75cc heads will be a hit with the guys that have low compression shortblocks that need a boost in compression. One thing that will need some checking is the bore shrouding. Oversize 2.14/1.81 valves with a small 383 (4.25in) bore can create clearance issues....best to check  



Ron

Firefighter your 100% correct... I saw that also in the Jegs advertisement & asked the same question, I was also under the impression they were out already, What I was told by a friend who is pretty spot on on this stuff most all of the time, said the 75cc version is the $979 & the 84cc version is $1470+ "I'm not sure if that is correct or not" {I am on the phone with Edelbrock tech. as I'm here waiting}, but I do trust the guy who told me... The 2.14"/1.81" intake valves will clear the tops of the cylinders, but some very slight notching/beveling in the immediate effected area is recommended for better flow, with out any valve shrouding problem... I called the source Edelbrock them selves, they said "They are the same port as the RPM", the 84cc versions are available now,  the 75cc is in delvelopment, some extra machining needed to be done, that caused a delay & will they will be out in arround 60 days & that price will be more like the RPM's not the $980 range, the only person I could talk to said " but there isn't a price on the 75cc head as of yet"... I suggested to him that it would be a very good idea to price them at the level of the Stealth heads that are $980 range... So I would guess the price that was said earlier will be much higher, after talking to the Edelbrock tech. rep., to bad-so sad, I'm profoundly sorry for any confusion I may have caused over the pricing, I will contact my cylinder head/porter friend & set him straight...

Budnicks yer dah man, but you ain't settin' me straight. If you call Summit Racing and order the 5090 heads now, you will get them for $979.95 WHEN Summit takes delivery from Edelbrock. I just called Summit and asked them. They gotta bunch of 'em on order. I am gunna get one of the heads, put on the flowbench in stock form, then port it and reflow it......Jim

I can't wait to see what you get from them in flow & CC #'s Jim

[XH29N0G]

Hi All,

I spent the past weekend swapping the cam and believe I did things correctly, but this is the first time I have done this and I have not been able to get the car to start for break in. 

It backfires through the carburator but does not start. 

The information I can provide is:

The disassembly/install
1) I scribed a mark in the distributor when I removed it and returned it to the original position. 
2) I used a degree wheel to check the Cam and it looked OK with respect to TDC and opening/closing of the intake on #1.
3) I was not able to do the intall in one day.  Day 1 was spent disassembling, day 2 & 3 spent reassembling and tracking down leaks in heater hoses, day 4 (today) spent tightening rocker arms and buttoning up
4) I did scratch the cam bushings on removing the old cam (I think it had to be me), several had a 2mm x 0.5 mm scratched that I initially took for inscribed numbers, but then realized they were scratches.
5) I believe everything else went the way it should.

Trying to start the car.
1) There is a regular backfire and the car does not catch.
2) I advanced and retarded the timing trying to start the car with little change. 
    At one point my son said it started to backfire out the exhaust rather than the carburetor.
3) I initially started with the idle adjustment screw set in (the setting was 2000 RPM before starting)
       - I returned it back to the original setting

Can someone give me advice on what I should do next.

I need advice on what to check, or if I have to go back, how far back I have to go.


Thank you,

James

[AirborneSilva]

I know you said you marked the distributor but it still sounds like you are 180 degrees out, id pull the distributor and rotate it 180...

[willard]

Try with distributor 180 off. As you - I wrote down the position of the reluctor and then reassembled it same way. I got terrible backifre and couldnt start the engine. Yup, the dizzy was 180 deg off...
So set it 180 deg off, adjust timing and here you go. (I hope!)

[XH29N0G]

Thank you,

Yes, the distributor was 180 degrees off.  Now I am trying to figure out why/how that happened.  I have pictures of the before and it looks like it was 180 out then, but that does not make sense to me. 

I switched the distributor, it started, I ran it at 1800-2500 RPM for 20 minutes.

Now I am working on checking everything out.  It is not quite right, but it is pretty close.  Vaccum is at 17 inches, but jumpy, and every so often there is a little stumble when idling.  My guess is that these will be sorted out.

I checked for the compression stroke and that is right now with the #1 firing at that time.

One more thing I found interesting.  This was the first time the engine was apart and I noticed that the vibration damper had a layer of blue paint under the orange paint.  The rest of the engine does not appear to have this.

Thanks again

James

 

[XH29N0G]

A thank you for the recommendations. 

I took the car for a longer drive today and it feels considerably stronger than before and than I expected.  I still need to work through tuning and carburetor adjustments.