Hemi crate engines

[HemiMunzy]

Hi there,

I'm interested to know if any has experienced or
has heard of someone having the same types of
problems with the MP crate hemis.

I bought the stroker 472 about 2 yrs ago.
equipped with the original spark plug wires,
chrome box, MP distributor, 850 mighty demon and tti headers,
it just never really runs 'right'.

Its got plenty of power - that's not it ,
but i have to play a lot with the ign. timing to
avoid detonation (even with the 9:1 CR) i have it
down to 0 degrees to keep the total timing in the 28
degree range and only use premium fuel.

I have adjusted a rocker (hyd lifters) on the right bank
4 times already because its so noisy.

The 850cfm was recomended by MP - but the plugs
are always sooty and it runs very rich.

It leaks coolant from the rear of the right cylinder head.

I get frequent engine run-on.

I mean the engine has maybe 2000 miles on it,
is this weird? Or totally normal?

[ehostler]

Do a searh here. You will find plenty of bad about these crates. I have even heard of different piston (different compression heights) in the same engine.

I would pull apart the engine and go through all of the tolerances and torque specs.

The Chrome box isn't bad, however there is better (out thereFBO systems, Jacobs, and MSD). Also, I would contact Don over at FBO Systems and talk to him about your engine and carb. He can tell you if that is actually the correct carb. If it is, he will give you some good pointers on tuning it.

You may also want to look in the archives. There are some tuning procedures there.

[avhoppet]

To me the low speed system of HolleyÂ’s seem to run rich over the transfer slot. DonÂ’t know if the Demon is alike. Anyway, the main jets do not affect the low speed system too much, so playing around with main jets disturbs the main system and is not the way to go. Therefore I am used to install smaller low speed jets in the metering plates. Those are pressed in and very small. One may also tap for Mikuni low speed air bleed jets in the main body and go up in air bleed size. But the gasoline jets make a bigger difference.

Ok, this may be a tricky operation for a person not used to work with carbs, but the problem is that there is no easy fix if rich low speed is the problem and the adjustment screws is less than half a turn open.

It is VERY important not to run rich in the low speed area, otherwise the combustion chambers get sooty and the engine does not respond on the throttle. And the soot glows and creates preignition, afterrun and exhaust bangs under load.

Goran Malmbe

[DonP]

I'm planing on getting a crate hemi for my 71 cuda so keep a close lookout for post like these.

Off topic, is there any other way of getting a hemi besides a crate for the price of a crate (or less?)

On topic, I know you have a deamon, but in the Holley books I read, there is a section on making a double pumper streatable by leaning out the jets and making the power valve kick in at a lower vacuum. This assumes you are not racing your hemi and that you just take it out on the street.

Carbon fouling from running rich would cause compression ratio to increase and could make hot spots that cause detonation - so I'd recommend something to clean out carbon buildup in the cylinders.

Also, the 472 stroker hemi puts out 510hp - does it do this on a 9:1 compression?

[ehostler]

Demon Tuning 101

[HemiMunzy]

Thanks guys and appreciate all the good advice for the demon
tuning - I bought and read all the books and although
Demon tech actually came back wit ha reply that I should
have bought the 750 Vacuum sec carb for the 472 Hemi - unless I buy another $500 carb - I'm screwed.

Didn't think of the carbon causing the hot spots -
it was running so rich for so long - that could definitely be the cause of the pinging and run on.

The other interesting thing from the Demon tech line was the advice that i should be running 18degrees of initial timing.
I don't know but my total (mech plus initial) gets into the
39 degree range which means crazy-detonation for me.
My vacuum advance I always keep plugged.

Even with all this happening - this 9.0:1 CR
Hemi pulls my 1972 Satellite into 12.5's at 113mph.
Its great fun - but I would like the engine to run well all
the time.

[DonP]

I hope to join you with a hemi of my own someday, but I wish someone would recommend what to do if crate motors are not the way to do it.

Is a crate motor still bad if you tear it all apart making sure everything is to spec and then put it back together?

[ehostler]

By pulling it apart, checking everything, and replacing the incorrect stuff, the crate is then a good engine.

Honestly, I would buy an RBRE engine for close to the same price (a lot more if you want more power). They have very highy quality standards and build great engines.

[23T]

I've tried all makes of crate engines and the best way to describe a crate engine is " All parts included in a compact shipping container some re-assambley required"

I know some will swear by them but any engine you buy that has NEVER been started can have serious problems.

Does blind date ring a bell?

[HemiMunzy]

You all are a 100% right - but given the fact that it was
the Hemi way for me or NO way - i couldn't find
an easier, quicker and - quite frankly - cheaper way to get my
hands on a real Hemi engine.

I went through the process of finding a used one
that was to be rebuilt by the seller (an accomplished race engine
builder himself) but a 2 month build time - became an 9 month
lesson in patience. Out here in Montreal , our driving season for these cars are like 4 or 5 months. So it gets pretty lonely waiting 2 summers for an engine to be built.

I ordered the Hemi from Chrysler on a Monday and the dealership called me back the next Tuesday asking me where my house
was so they could deliver it to me - in the back of a new Ram 2500.
It was a pretty good experience actually.

It just sucks to know that I may have to spend half of
what I paid for it - to have it rebuilt w/3000 miles on it.

Honestly, I am just going to keep it running best I can and
stick it out as-delivered.

This website has been great and thanks to all who offered me their ideas.

[DonP]

Looking at your original post at the problems you are having:

1. Runs rich
2. Run-on after shutting off
3. Detonation
4. Water leaks
5. Lifter adjustments

Before doing a full tear down, I think you need to get the carb tuned first. Run something to get the carbon out of the cylinders. But if the water leak is bad, tear off the head and see what is going on in the cylinders.

It's hard to say, but could it be that the carb out-of-tune is the causing some of the problems with the motor? I would be curious if the motor always had detonation issues or if they cropped up over time from running rich.

[HemiMunzy]

Thanks Don P,

Definitely would say that all these problem cropped up over the
first 6 months of driving.
I remember no detonation (or engine run on) until after
about 700 miles or so and after the carb switch.

I first ran the engine with a 750 edelbrock but was so convinced by> 1. word-of-mouth and 2. the hard to read "foreign-style" 4 page instruction sheet that came with the engine - that I needed an 850cfm carb asap. People told me that I was killing my Hemi with that small carb!

It was definitely after the switch that it ran rich and then the other problems. I will go out and buy a can of combustion chamber cleaner and once the carb (and timing!) are finally tune I will also use that to clean the chambers - hopefully solving at least some of the problems.

I jetted down two more numbers on both the Primaries and secondaries (this is the second time) and I still don't see a big
improvement - but the black smoke is actually less now when I gun it.

I timed it back down to 28degrees total and the detonation has
stopped - but feels sluggish.

I may actually send my Mighty Demon back to BG - as they said I bought the wrong carb - I have downleg boosters but should have bought a carb with annular boosters. Too bad summit's tech line couldn't have told me that when I asked them before ordering it. Go figure...

[MoparMarcIdaho]

put it back on.clear your combustion chambers and watch the water leak,go have some fun.

[wedgehedd]

I have taken perfectly good motors apart before only to realize it was a simple fix. Demons should have been called Gremlins, but when you get them tuned they will break your neck. I have a BG Sportsclaw, the predecessor to the DEMON and the power valve seemed to be crutial on mine. Set the timing where you know it should be and get it to run to that. Verify TDC at the distributor drive gear and then lock it at 34 total. Choose a power valve that is 2 below your vacuum signal at best idle (10.5 vacuum=8.5 power valve) then drive it enough get a good read on the plugs. Get a box of jets and step em one at a time without changing ANYTHING else on the motor, get it leaned out first then worry about fine idle and timing adjustments. I bought an O2 sensor setup that I use on all my cars, it takes alot of the guess work out of jetting. also, adjustable timing on the dash from MSD is a must for street/strip use. Hope this helps, I have lots of experience in what NOT to do. P.S. you don't even know what that motor is capable of yet, mine (not a hemi, just a 453 wedge)turned from a flacid poop factory into an adrenalyzed hair raising monster just by tuning the carb, hope this gives you something to look forward to.

[waldo67]

dp carbs dont need to be retuned for street use i had a simular problem on a small block i drooped the power valve down to a high flow 2.5 and played with squirters size and the jets also and it does make a difference a bid difference drop the pv down play with the squirters and jetting

[DonP]

Originally posted by waldo67
dp carbs dont need to be retuned for street use i had a simular problem on a small block i drooped the power valve down to a high flow 2.5 and played with squirters size and the jets also and it does make a difference a bid difference drop the pv down play with the squirters and jetting

Waldo,

I think most of us consider changing power valves, jets, and squirter sizes retuning

What do you call it

[Dick]

RE.: Crate Motors;

I had done a little research on this subject before, since I was considering a street crate 360 just for kicks and giggles.

I had read some negative posts about crates in general. Most of the stories were about loose bolts (inside!) missing rings, incorrectly sized bearings and assembly flaws. Even the MP tech advised over the phone that the street crate 360 wasn't that much more powerful than the 235 horse unit in my truck. He said the crate was around 260 and it wasn't even advertised as that. He did say, off the record, that if I bought one to tear it down and check everything for fit and torque.

I asked him if these engines were built on Chrysler's engine line and he said no. They were built up at low-bid engine shops. Whatever.

The only good response I read in my search was from a Canadian who claimed that some crates are built in a Canadian plant and they have quality equal to or better than the OEM units in new cars. He said if I could order a crate and specify Canadian built I wouldn't have any problem and would have a good motor.

I contacted the dealer that was going to sell and install the crate (they were very anxious to install it and even had a couple of engine mechanics volunteer to stay after hours to do it) and asked if they could order a Canada built crate and they said it would come from wherever DC had them available.

At that point I gave up on the idea and figured I would try to get another 100K out of my oil thirsty 360. I am at 180K now and it still pulls hard.

[MoparMarcIdaho]

you would sure think that you could get a quality engine from Diamler Chrysler,whats the world coming to anyway?I have a 71 440 HP in my service truck and it has never been touched as far as rings,bearings,cam,heads,I had to replace the rear main years ago and bought a new set of bearings just in case.It didnt need them.I have a slightly smaller carb on it but outside of that,its stock.Try to get that kind of life from todays engines and see what happens.

[waldo67]

hey don p you sre correct what i was going to say was detuned for the street i just had my head up my but on that one but thans for the catch

[HemiMunzy]

Thanks for the input on the Power valve tuning - I will be diving into that for sure - it might just be the problem as the Hemi at idle is pulling 9.5hg vacuum.

Funny that Dick should mention the Canadian built vs elsewhere for the crate motors from DC - When I fisrst decided to go to the dealer to order the crate hemi - I first wanted to know how long it would take me to get it - because that was the big lesson I learned with the "used 426 Hemi" i never ended up getting after an 8 month wait.

The parts manager checked on the computer and told me that there would be 3 - 472ci stroker hemis ready for sale (built) in the 2 weeks to come. He told me that one of them was already ordered by a fellow in California and the other by a customer in Connecticut - they would still have 1 left before it hit backorder status and average build time was anywhere between three months to six.

I said I would think about it and get back to him - the price was just about $20K CAD including taxes. I asked if the engines were built in the USA and he said - he couldn't say they could be built anywhere the factory decided.
I did make the order the next day.

When I got the engine - it came with what best could be describes as a super crude photocopied instruction sheet of 4 pages.

On the engine and blue plastic crate it was in - were all sorts of codes and upc symbols all of them basically indicating "built in the USA" - one of them mentioned a company called "OER" after researching I found out this was a Cummins Diesel Plant in Ontario somewhere and I contacted them - they ended up not telling me anything of interest - but it did get me my actual serial # matched Dyno sheet - the engine had made 514HP and 518lb-ft of torque. The dyno used a 750 cfm vac sec Holley and timing was at 36 degrees. Did it knock on the dyno?
Who knows.
Plus I realized that it had already been broken in.

Hope that helps anyone with crate engine inquiries

[Plum6Pak]

After reading through some of the posts here about the crate engine hemi, I couldn't resist puting in my 2 cents worth. The hemi is a nice engine and is legendary to say the least but, the 440 on low end if built correctly will have that hemi watching your tailights. For about half of what you can get a crate hemi for, you could build a 440 into a stroker that has more torque and horse power and still streetable. I am not bad mouthing the hemi but it was originally made for the higher rpm racing and that is where it's power comes in, the stroker would be a much stronger more economical approach. I too have talked with an experienced Mopar engine builder who has had to repair some of these crate engines right out of the box. As stated, it's like going on a blind date, unfortunatly this post is just another example of this. If you are looking to turn heads at the local shows the hemi is the one that will do it, you want them watching your tailights? Stroked 440 all the way.

[avhoppet]

Originally posted by Plum6Pak
For about half of what you can get a crate hemi for, you could build a 440 into a stroker that has more torque and horse power and still streetable.
I too have talked with an experienced Mopar engine builder who has had to repair some of these crate engines right out of the box. As stated, it's like going on a blind date, unfortunatly this post is just another example of this.
If you are looking to turn heads at the local shows the hemi is the one that will do it, you want them watching your tailights? Stroked 440 all the way. [/B]

Allways hard to discuss the balance cost vs power as we dont know what everyones wallet looks like. But most of the time money is a big factor.
The crate Hemi may be a good choice of one like the concept. All parts needed for a reasonable price in a mock-up for easy delivery. Giving insurance all parts is included (still hopfully).
Then on must build a motor from it.
If any engine needs to be bored and stroked for street use, it is the HEMI, in order to get reasonable Cr ratio without to domed pistons. Then we have both the looks, Tq and Hp, even if not very cheap.....
Goran Malmberg

[DonP]

Originally posted by Plum6Pak
After reading through some of the posts here about the crate engine hemi, I couldn't resist puting in my 2 cents worth. The hemi is a nice engine and is legendary to say the least but, the 440 on low end if built correctly will have that hemi watching your tailights. For about half of what you can get a crate hemi for, you could build a 440 into a stroker that has more torque and horse power and still streetable. I am not bad mouthing the hemi but it was originally made for the higher rpm racing and that is where it's power comes in, the stroker would be a much stronger more economical approach. I too have talked with an experienced Mopar engine builder who has had to repair some of these crate engines right out of the box. As stated, it's like going on a blind date, unfortunatly this post is just another example of this. If you are looking to turn heads at the local shows the hemi is the one that will do it, you want them watching your tailights? Stroked 440 all the way.

I totally agree, but there is just something about the words Hemi 'Cuda that really do something for me

[DonP]

Originally posted by waldo67
hey don p you sre correct what i was going to say was detuned for the street i just had my head up my but on that one but thans for the catch

Not a problem. I found the same info on making Holley DP's streetable in an HP Holley book (can't remember which one).

[Plum6Pak]

Originally posted by DonP
I totally agree, but there is just something about the words Hemi 'Cuda that really do something for me

I agree, but due to finances I went with the 500 stroker, not a crate stroker but from the ground up. With Eagle 4.15 forged crank B1BS heads, Manley rods, JE forged pistons, new Mopar block siamese bored with cross bolted mains, sixpack setup all brand new dyno'd at 560 hp and 591 fpt and still well less than the cheapest hemi. But like you said, something about a "Hemi Cuda" mine is actually a 70 Challenger but still a 500 SixPack Stroker Challenger sounds cool too. Nothing will ever replace the infamous Hemi though.

[HemiMunzy]

Well,
The whole "hemi" mystique definitely figured in my plans to getone.

When I spoke to the first guy wanting to sell me his 1966 426 - he asked me how fast I wanted to go with my Satellite.

I told him the truth - that I currently had an '87 ragtop vette and
i had modified it enough to run 14.2s on the 1/4 (which seemed plenty fast at the time - especially on the street)
so I told him if I could be in the low 13's I would be very happy...
well the guy broke up laughing and just kept saying I didn't need any Hemi to do that - and I should stick to a small block or 383 at best. He pointed to me like I was nuts or something..."this guy wants a Hemi to run 13's!"

The truth is all i really wanted was the Hemi - it wasn't about just the strip - I wanted to have a piece of history.
To own the legend... as they say...
I wanted to open my hood at the show and shine and see those big hemi valve covers.
I knew all along I could have gone quicker - cheaper.

But don't forget that a hemi does have some value to it - even in used condition - I couldn't sell my used 440 for a $1000 - and I had $4000 put into it.

[Plum6Pak]

Yup, the hemi is a legend, it would bring a lot of value in years to come, a worn out 440 doesn't do that unless it is an original numbers matching SixPack engine or a certain one someone is searching for. I guess you could call the hemi an investment of sorts, I don't believe the crate hemi's will bring the same value as a date coded 66-71 would though. All I know is I cannot wait to fire up my new stroker, I have about 6 months of work to do to the car first then yeeehaaaaa!

[bigiron]

I aggree 100% with "There's nothing like a HEMI." That's why I bought one myself... I had one when I was 16 and got another one at 45 both 426's.

Even if I could build a quicker 440 or whatever it would not be a HEMI.

http://www.omniracing.net/manip_DSCF0042.JPG

Allready the reputation of this car has filtered through town and every one I talk to seems to know as much as I do about it, the only blowen HEMI in the area. There are a few blowen Chevies around and they get very little notice.

When I first recieved it I did have my friend (That has been a Mopar Mech for 27+ years) tear it down and check it out. He told me later it didn't have to be done on THAT partcular engine, everything had been right but he went on to say that the only way to know that for sure was to tear it down.

He charged me $500 and gaskets to do it.... think about it your sitting with what... mine ran around $10,000 the bigger one was about $1000 bucks more.... (I wanted the 426 even if it had been more than the bigger ones) what's $500 even $750 to know things are right with the engine.

Boy... I could go on and on and on about this project but......

I just wanted to say "Yeah it's a HEMI"

[Dick]

This thread seems to have focused on the crate hemis as if Chrysler didn't build a decent engine until 1966 and that re-pros are the way to go.

Doesn't anyone play with the original hemis from the 50s any more? Remember, the 66 hemi was brought out and rode on the reputation of the 392 Chrysler Hemi.

Displacements of early hemis ranged from 331CI to the 392, with a 354 in the middle. Dodge also had a 325CI hemi in the 1957 D500.

The 392 was THE engine to have in rail drags. Parts were plentiful, as were the blocks and heads. This was a production passenger car engine and it was plentiful. It lended itself to supercharging and was very strong.

I guess my question is, have all the venerable 392s gone to hemi heaven?

[bigiron]

I agree with you,the 392 still has it's place in history. But it was the 426 that was detuned from the race version that became feared machine of the 60's wheather earned or not.

The 392 started the reputation but it was the cross bolt mains, the dual 4bbl carbs, the advertised 425 (That everyone knew was conservative.) factory headers, all the cool stuff that the 426 came with that really became the legend.

I know Ford had it's 427 Chevie had the 409 and 427 and other manufacturers had there own performance engines but I think it was the fact that the 426 was allways a detuned race engine and only came as a detuned race engine, while all the others were made into performance engines first offered as production engines. I think I'm lieing about the 427 Ford though, it comes to mind that it was first intoduced as a race engine, but then it's just a Ford and who really could take them serious?

No.... for me the 426 was, is, and allways will be the legend... that is why I choose it above the strokers. But that's just my opinion. Nothing to get upset with me for.