425 Cam Selection - Need Advice
#1
425 Cam Selection - Need Advice
I'm building a 425 High Compression engine for my 66 Delta 88. Everything is going back pretty much stock with the exception of the exhaust which will breathe a little better. When doing this, can I install a mild cam without changing anything else? This car will never see a strip, only the car shows, the street & an occasional traffic light show off. I really just want it to have a more aggressive sound & idle, I'm not too concerned with high performance. Any advice would be greatly appreciated. Thanks!
#2
Since you have a 425 from a 66 Delta 88 you have the normal .842" lifters. You should be able to get an aftermarket cam easily for your engine. Check out the following website for some good choices.
http://www.supercarsunlimited.com/
http://www.supercarsunlimited.com/
#6
i went to supercarsunlimited.com & they only list OE replacements for cutlass/442. They don't have anything listed for a 425 or any higher performance parts. Am I missing something?
#7
I am sorry. I forgot that Supercars only carries factory replacement cams. Try the following websites.
http://www.summitracing.com/
http://www.jegs.com/
http://www.mondellotwister.com/index.htm
http://www.summitracing.com/
http://www.jegs.com/
http://www.mondellotwister.com/index.htm
#8
I just checked & I do have the 45 degree bank with the .842 lifters.
Thanks for stopping me before I screwed something up.
As much as I enjoy hanging out with friends & working on cars, I wouldn't want to stand around with them for hours listening to everyone giving me different reasons why the timing is off.
Thanks for stopping me before I screwed something up.
As much as I enjoy hanging out with friends & working on cars, I wouldn't want to stand around with them for hours listening to everyone giving me different reasons why the timing is off.
#10
#11
Thanks for all your input. I called some of the places that you guys suggested & the guys over at Mondello were the most helpful (or at least the most eager to sell me some parts). I ordered the cam & lifters from them today. I'll post again to let you know how it works out when I get this thing running. It will probably be a couple of weeks.
Mondello cam JM-22-25-10
lifters 555-H
Mondello cam JM-22-25-10
lifters 555-H
#12
I've finally got the 425 all back together, in the car & running. It's beautiful, but the timing is not right. After trying for a while, I'm starting to worry that there is a camshaft problem. What exactly would the symptoms be if the cam were the wrong one? I was 100% certain that I had the 45 degree bank angle when I ordered the cam, but I guess there is always the possibility that Mondello sent me the wrong one.
#13
When they do get the parts right, they usually come all scratched/biffed up. If/when you send it back, they will say they can't do anything because you damaged it.
I hate ordering anything from there. Stay away. If you do have a timing problem, I also suggest that you refrain from buying one of their 50 dollar timing tabs
#14
Mondello is known to put their names on other parts..Order a piston set from them and you will find out that it is a set of Keith Black pistons. I wouldnt be surprised if they do the same thing with camshafts. I wish I read your post months ago and I could of saved you a couple of $$$. You could of had a custom cam ground to your specs and had better results - and probably for less money too
#16
2 things...
(I first read this post thinking it was new...)
Yeah, Mondello can be a pain. I had a bunch of orders screwed up.
I was gonna say check everything thoroughly before install.
Like take the cam down to a machine shop and have them measure everything.
The second is...that's pretty stout cam. 108 LSA is not what you were looking
for IF you wanted just a hair above stock for an agressive idle.
What's stock lift in a 66 425? About .468"
Your new cam has .520.
Your valve geometry may be on the ragged edge of misalignment.
Your not going to be pulling as much vacuum as you were.
That cam has the potential to run low 12's in a 425.
I don't think it was the right choice.
-Sorry, I know you didn't want to hear this opinion...
And someone correct me if they disagree.
(I first read this post thinking it was new...)
Yeah, Mondello can be a pain. I had a bunch of orders screwed up.
I was gonna say check everything thoroughly before install.
Like take the cam down to a machine shop and have them measure everything.
The second is...that's pretty stout cam. 108 LSA is not what you were looking
for IF you wanted just a hair above stock for an agressive idle.
What's stock lift in a 66 425? About .468"
Your new cam has .520.
Your valve geometry may be on the ragged edge of misalignment.
Your not going to be pulling as much vacuum as you were.
That cam has the potential to run low 12's in a 425.
I don't think it was the right choice.
-Sorry, I know you didn't want to hear this opinion...
And someone correct me if they disagree.
#17
The first thing I did was check that #1 cylinder was at TDC & the distributor matched. Then I idled it up to about 1000 rpm with the vacuum line removed & adjusted the distributor until the motor ran as smooth as possible. When I put the light on it, it showed that it was 6 degrees off. If i adjust the distributor to get the timing to 0, it runs rough, gets rougher, backfires through the carb. At this point it idles back up momentarily, then does the same thing again. It definitely runs best at higher rpms. When I drive it, it starts out feeling like it lacks power, then picks up as the speed increases. The car is basically a rolling chassis, so I can only test it out in the parking lot. When you rev it in neutral, it actually sounds really good.
I'm now thinking that the cam is ok, & that maybe the 3 key timing gear was installed on the retarded setting. Would that explain the 6 degrees & the symptoms I'm experiencing?
I think I'm going to pull the timing cover off & check it to be sure, unless anyone has another suggestion to try first.
I'm now thinking that the cam is ok, & that maybe the 3 key timing gear was installed on the retarded setting. Would that explain the 6 degrees & the symptoms I'm experiencing?
I think I'm going to pull the timing cover off & check it to be sure, unless anyone has another suggestion to try first.
#18
As far as the cam selection, I pretty much relied on the information they gave me to make the selection. I told them I was running a stock motor with the exception of adding dual exhaust & that I simply wanted to give it a more aggressive idle/sound. Then I went with his recommendation. This is my first engine build, I got some help on the assembly, but basically did everything based on the information I gathered from several sources, including this one. Can I make it work? Shouldn't I still be able to get some power out of this thing?
#19
Yes. It will definitely make power...
It just seems pretty big for what you originally stated you wanted.
What gears & converter were you planning on using?
A heavy car with highway gears and that cam isn't optimal.
Where's Norm when you need him?
I'd like his take...
It just seems pretty big for what you originally stated you wanted.
What gears & converter were you planning on using?
A heavy car with highway gears and that cam isn't optimal.
Where's Norm when you need him?
I'd like his take...
#21
I am not following your timing method.....with a timing light you need to adjust dist. for advance with the engine running not zero. You install dist. at zero TDC compression stroke on #1 cylinder. You will need to advance the timing as much as possible without having the engine ping for better engine output. I dont know cam specs. but if they are what were posted that is a lot of cam for a stock engine...a cam like that needs a lower rear end gear and a higher stall torque converter. The trouble you say when driving about starting out with no power then the engine picking up some is typical performance with a big cam in a stock engine....poor driveabilty.
#22
Wow. Why would you EVER want ign timing at 0?
You need ignition advance.
That needs to have 36-38 degrees advance (no more than that) by 3000 rpm, with vacuum advance off. Put a mark on the BALANCER 2.009 inches to the right of the factory mark. Run the engine up to 3000 rpm and advance distributor until you line up the new mark with the 0 on the pointer.
***Make sure the engine does not try to advance more at a higher rpm, you need to keep a limit of full advance to 38 max.
***After this step, you need to purchase the best fuel you can find, or back down timing until it does not ping anymore!!!
You need ignition advance.
That needs to have 36-38 degrees advance (no more than that) by 3000 rpm, with vacuum advance off. Put a mark on the BALANCER 2.009 inches to the right of the factory mark. Run the engine up to 3000 rpm and advance distributor until you line up the new mark with the 0 on the pointer.
***Make sure the engine does not try to advance more at a higher rpm, you need to keep a limit of full advance to 38 max.
***After this step, you need to purchase the best fuel you can find, or back down timing until it does not ping anymore!!!
#23
Similar to my Isky 280 Mega. If I was looking for an “aggressive” idle, instead of a specific power output, I would have stepped up to the (12ş more duration, .050" less lift) 292.
But then, everyone here will have different perceptions of “aggressive”.
Should be an Engle cam with a Mondello part number..
Not a 108.
The -10 after the JM-22-25 (108ş) makes it JM-22-25-10 (110ş). For his application/goal, it wouldn't make any difference.
Nothing to do with the topic. Unlike duration/overlap, lift will not help him to reach his goal.
Not even close. .584” was not ideal, but it was not a problem.
I believe someone else, on this board, has gone higher.
That is a given. I would bet that vacuum was discussed during that conversation with the Mondello tech.
As I recently found out, opinions are what discussion forums are all about.
And disagreements lead to discussions, which (in theory) lead to the dissemination of factual information.
And that information was based on your input. All he/she did was choose (from the catalog) the profile that (in his/her opinion) fit your input.
With a recurved distributor that matches your combination, it will work fine.
No need to. He already made his choice. I just dropped by to see who I can pizz off.
Once you've found the optimum total, you can experiment with initial settings to find the “idle” you want.
Less advance = more radical idle = slower throttle response.
More advance = smoother idle = quicker throttle response.
Once you have both numbers, the advance “curve” needs to be modified, to meet (without the vacuum advance) your new requirements. Look for a “tune up” guy that has a Sun distributor machine.
Norm
#24
Well, the above is just what I asked for...
Exactly.
I 'read into' his desire for a more aggressive idle as more
then just an aggressive idle. I thought it was the desire to just step
it up over stock in both sound and performance but err on the side
of drivability over all out speed.
Maybe I read into it wrong.
So Norm, you're saying this will fill the bill perfectly...when
it comes to him choosing a cam for the sound it provides...?
OK.
But I still think without proper gearing and converter he won't be happy
driving around with this cam installed.
As far as:
Some one achieved this without any shimming or spring perch modification?
With stock rockers and bridge and springs?
Wow.
None for me thanks.
And disagreements lead to discussions, which (in theory) lead to the dissemination of factual information.
I 'read into' his desire for a more aggressive idle as more
then just an aggressive idle. I thought it was the desire to just step
it up over stock in both sound and performance but err on the side
of drivability over all out speed.
Maybe I read into it wrong.
So Norm, you're saying this will fill the bill perfectly...when
it comes to him choosing a cam for the sound it provides...?
OK.
But I still think without proper gearing and converter he won't be happy
driving around with this cam installed.
As far as:
Not even close. .584” was not ideal, but it was not a problem.
I believe someone else, on this board, has gone higher.
I believe someone else, on this board, has gone higher.
With stock rockers and bridge and springs?
Wow.
None for me thanks.
#25
"Some one achieved this without any shimming or spring perch modification?
With stock rockers and bridge and springs?
Wow."
Back in '79 I used a Mondello/Engle cam in a 425 with .590 lift on the exhausts...intake was slightly less. I cant find the cam card but used stock valve train with exception of adjustable pushrods. Did not have a problem and did not break anything but axles
With stock rockers and bridge and springs?
Wow."
Back in '79 I used a Mondello/Engle cam in a 425 with .590 lift on the exhausts...intake was slightly less. I cant find the cam card but used stock valve train with exception of adjustable pushrods. Did not have a problem and did not break anything but axles
#28
Reading into it = Reading what is not there = Reading what one thinks, is there.
When reading something that is not there, how does one determine which part is "wrong" vs which part is "right"?
Did I say that?
First you edited the original post, by adding the modifier "hair",
then you edited mine, by adding the word "perfectly".
Is there anyone here, who does not understand why I "post the quote" ahead of my response?
Maybe, maybe not. He did not ask about gears or converter, he asked for cam advice. Which leads to the obvious question:
From the information given, how do you know what will, or will not, will make him happy?
Yes.
The two members above,
plus a third.
I cannot speak for anyone else, but I used the same pushrods that came with the engine.
In our defense, I believe we all did it before we discovered (via the Internet) that it is not possible.
Norm
When reading something that is not there, how does one determine which part is "wrong" vs which part is "right"?
Did I say that?
First you edited the original post, by adding the modifier "hair",
Is there anyone here, who does not understand why I "post the quote" ahead of my response?
From the information given, how do you know what will, or will not, will make him happy?
I cannot speak for anyone else, but I used the same pushrods that came with the engine.
In our defense, I believe we all did it before we discovered (via the Internet) that it is not possible.
Norm
#29
When doing this, can I install a mild cam without changing anything else?
God Norm, your so pedantic.
Your so worried about proving your knowledge about the smallest details
that you miss the big picture.
Do you think that's a mild cam that he picked?
Do you think it was the best choice?
That cam is meant for a car that's either going to be a boulevard bruiser
or will see some track time. IMHO, it's not a good cam for a land yacht,
with possible highway gears that will be idling around town and occasionally lighting the tires up at a street light.
If someone asked you for directions to the supermarket, and you realized
their car was on fire...I honestly think you'd pull out a map and then wave
them off.
-go ahead, pick this apart and show me what I misspelled, guessed wrong,
misunderstood and don't understand.
#31
wow, I gave up reading that about 3/4 of the way through. I'll have to come back for a 2nd sitting. I do appreciate all of the input though.
I showed it to a buddy who builds race engines & he said it sounds like my valves are "floating". He recommended that I definitely beef up the valve springs.
I believe we have ruled out the cam being the wrong bank angle.
It sounds as though it's mis-firing & the plugs turn black very quickly. It did the same thing with the old quadrajet as it does with the new edelbrock I have on it.
I showed it to a buddy who builds race engines & he said it sounds like my valves are "floating". He recommended that I definitely beef up the valve springs.
I believe we have ruled out the cam being the wrong bank angle.
It sounds as though it's mis-firing & the plugs turn black very quickly. It did the same thing with the old quadrajet as it does with the new edelbrock I have on it.
#32
I can't help you much with the problem itself but I can tell you I have the same cam in my 425 and it works really well. I had some of the issue you have but it was mostly timing related. Since I did a complete bottom up rebuild I was able to degree the cam so I knew it was spot on. I trashed the old distributor and went with an MSD system, advanced the timing to about 30-36 degrees then worked on the spring set up in the distributor until I got it coming in full on at around 2500 - 2800 RPM. Then went back and retarded it a bit to get a harder sound. All in all, I am very happy with the cam and performance, can't keep rubber on the tires though so looking to change the rear end to posi. I did upgrade valve springs etc though. This probably wont help much except give you comfort that the cam works great with the right set up.
#34
And again, the "engineer/moderator" showcases his psychic abilities.
Your childish personal attack belongs in a PM.
From the beginning of my first post:
Since he already owns it, it doesn't matter much, does it?
Doesn't matter what I think, he already owns it
Another immature comment that belongs in a PM.
Having trouble keeping up with an adult discussion?
If you would like to discuss it further, send me a PM.
Norm
Your childish personal attack belongs in a PM.
From the beginning of my first post:
Doesn't matter what I think, he already owns it
If you would like to discuss it further, send me a PM.
Norm
#35
After I posted, I decided to do the same. Considering his immature attitude, I was curious whether I had been insulted, or not.
http://thesaurus.reference.com/browse/pedantic
Sounds like some "engineers" I've dealt with.
It seems, I am long on education, and short on knowledge/experience.
Either I have had more schooling, and less experience, than I thought, or he intended that as a juvenile insult.
Or is it, that he does not understand, that the difference between "winners" and "losers" is in the details. Naw, can't be. Any "engineer" would know the value of details.
Biggest reason, I use the thesaurus.
Norm
http://thesaurus.reference.com/browse/pedantic
Originally Posted by thesaurus.com
........ Characterized by a narrow concern for book learning and formal rules, without knowledge or experience of practical matters.
It seems, I am long on education, and short on knowledge/experience.
Either I have had more schooling, and less experience, than I thought, or he intended that as a juvenile insult.
Or is it, that he does not understand, that the difference between "winners" and "losers" is in the details. Naw, can't be. Any "engineer" would know the value of details.
Biggest reason, I use the thesaurus.
Norm
#36
ijasond...Sorry this turned into a whine-fest in the middle of your problem.
Didn't mean to do anything other then alert you to some of the cams characteristics and possible downfalls when used in a car that heavy.
What gears do you have? Is it a 2 speed?
Like I said before that cam is capable of producing some stout #'s.
Engle grinds are some of the best.
If you can change the springs and sort out the timing issue the 425's
make for a killer street engine.
Didn't mean to do anything other then alert you to some of the cams characteristics and possible downfalls when used in a car that heavy.
What gears do you have? Is it a 2 speed?
Like I said before that cam is capable of producing some stout #'s.
Engle grinds are some of the best.
If you can change the springs and sort out the timing issue the 425's
make for a killer street engine.
#37
It's a 3 speed TH400. Gears are stock. I plan to change it over to posi at some point, so I'll sort that out soon. I'm going to get the valve spring set on the way, I know it's causing a problem so I figure I'll take care of that before I move to the next step. I still need to pull the timing cover & make sure the timing was set right during assembly. I just haven't had much time to work on it here recently. I'll try to get some pics posted soon.
#38
Back to that post I made about the timing. My brain farted all over on that one, maybe even sharted. When I disconnected the vacuum advance & ran it at 1000 rpm, It's about 60 degrees advanced, not 6. Sorry to get you all confused with that one. If I try to back it down below 40, it gets pretty rough.
As I may or may not have mentioned before, this is my first engine build & I've found that it is more beneficial to seek advice from you who have loads of experience with the Olds engines. Thanks to those of you who have been patient with someone who doesn't know what they are doing.
As I may or may not have mentioned before, this is my first engine build & I've found that it is more beneficial to seek advice from you who have loads of experience with the Olds engines. Thanks to those of you who have been patient with someone who doesn't know what they are doing.
#39
I'll save you some trouble. Following are the parts that actually relate to your original post.
........ What he said. ↑
Once you've found the optimum total, you can experiment with initial settings to find the “idle” you want.
Less advance = more radical idle = slower throttle response.
More advance = smoother idle = quicker throttle response.
Once you have both numbers, the advance “curve” needs to be modified, to meet (without the vacuum advance) your new requirements. Look for a “tune up” guy that has a Sun distributor machine.
Once the timing is addressed, we can deal with any loose ends.
Which part did he base his "opinion" on?
You did not get a "valve spring" recommendation from Mondello?
Sounds like it belongs in its own thread. This one does not need any more confusion. Is it a new, or existing, problem?
Quadrajet, as in before, or after, your cam change?
Norm
........ You need ignition advance.
That needs to have 36-38 degrees advance (no more than that) by 3000 rpm, with vacuum advance off. Put a mark on the BALANCER 2.009 inches to the right of the factory mark. Run the engine up to 3000 rpm and advance distributor until you line up the new mark with the 0 on the pointer.
***Make sure the engine does not try to advance more at a higher rpm, you need to keep a limit of full advance to 38 max.
***After this step, you need to purchase the best fuel you can find, or back down timing until it does not ping anymore!!!
That needs to have 36-38 degrees advance (no more than that) by 3000 rpm, with vacuum advance off. Put a mark on the BALANCER 2.009 inches to the right of the factory mark. Run the engine up to 3000 rpm and advance distributor until you line up the new mark with the 0 on the pointer.
***Make sure the engine does not try to advance more at a higher rpm, you need to keep a limit of full advance to 38 max.
***After this step, you need to purchase the best fuel you can find, or back down timing until it does not ping anymore!!!
Once you've found the optimum total, you can experiment with initial settings to find the “idle” you want.
Less advance = more radical idle = slower throttle response.
More advance = smoother idle = quicker throttle response.
Once you have both numbers, the advance “curve” needs to be modified, to meet (without the vacuum advance) your new requirements. Look for a “tune up” guy that has a Sun distributor machine.
Which part did he base his "opinion" on?
Norm
#40
Disconnect the MSD. Do not reconnect it until you are satisfied with the way the car runs.
Recheck your firing order. Counterclockwise = 18436572.
When you've found #1 TDC and verified the cam timing, do not move the crank until you are sure the timing tab matches the mark on the balancer.
Norm