My new Rx7 R1

ecam8000 · Postby **ecam8000** » Mon Jul 30, 2012 9:14

Just curious, but are the MSD boxes compatable with rotory ignitions? I've used them in the past for engines that fouled plugs, had poor idle and even to pass emissions. Used with point and electronic ignitions - stock and aftermarket coils. Had a coil wire come off at a tune and had welding arc type current seeking a ground!

Might be a solution to the ever flooding rotory....

http://www.msdignition.com/products/ignitions/

VRx8 · Postby **VRx8** » Mon Jul 30, 2012 9:14

Yes you can get the MSD to work on a rotary. HKS Twin Power will be a better option sence is plug N play. I used to have that problem with my FD, flooding constantly and fouling plug because of the weak spark. The cure for that was the HKS Twin Power.

4g63<13b · Postby **4g63<13b** » Mon Jul 30, 2012 9:14

VRx8 wrote:Yes you can get the MSD to work on a rotary. HKS Twin Power will be a better option sence is plug N play. I used to have that problem with my FD, flooding constantly and fouling plug because of the weak spark. The cure for that was the HKS Twin Power.

Kind of seems like what mine is doing but it wouldn't just start all of a sudden now?

chickenwafer · Postby **chickenwafer** » Mon Jul 30, 2012 9:14

A less expensive option than the HKS twin power is going an IGN-A1 ignition system, such as the AEM Smart Coils. They are rebadged Mercury Marine engine coils, are absolutely bullet proof, support over 2000bhp, and they also feature a built in internal igniter so you can delete the stock igniter on the FD. A much better solution.

4g63<13b · Postby **4g63<13b** » Mon Aug 20, 2012 9:14

Is it really possible for my car to start and idle with as low as compresion as it has, rear has like 75 psi and front has about 50

chickenwafer · Postby **chickenwafer** » Mon Aug 20, 2012 9:14

How did you get those compression numbers?

50psi is extremely low. Usually 90-80psi is considered a rotary knocking on deaths door, anything less and it will have an incredibly difficult time starting, idling, staying running, etc. Basically I'm saying I find it difficult to believe you only have 50psi on a rotor because I don't see how it could even run.

Piston style compression testers are a crap shoot. They are really only usefully to show even bounces between compressions faces. You want to make sure you have consistently even compression between each face, large variations are bad. The overall number a piston tester gives you will usually be quite low, especially with our altitude effecting the overall number.

VRx8 · Postby **VRx8** » Mon Aug 20, 2012 9:14

What compression tester are you using?
Did you check for even bounces?
What kind of vacuum are you looking at when idling?
Did you cranked the engine with the plugs off and hear how strong the pulses are?
Have you tried putting a little bit of oil thru the plugs and see if it runs better?
Have you change the plugs?
Have you check for spark?

I have done a compression test on my newly rebuild engine and showed like 50 psi can't remember for sure, but it was way lower than spec. So that being said you need to do all this troubleshooting steps before you say is blown.

4g63<13b · Postby **4g63<13b** » Mon Aug 20, 2012 9:14

VRx8 wrote:What compression tester are you using?
Did you check for even bounces?
What kind of vacuum are you looking at when idling?
Did you cranked the engine with the plugs off and hear how strong the pulses are?
Have you tried putting a little bit of oil thru the plugs and see if it runs better?
Have you change the plugs?
Have you check for spark?

I have done a compression test on my newly rebuild engine and showed like 50 psi can't remember for sure, but it was way lower than spec. So that being said you need to do all this troubleshooting steps before you say is blown.

i used two different rent testers from two different auto stores, same results with each
im reading like 10 or 11 vaccume at idle
yea iv cranked with plugs out but havent heard a good motor to compare
yes changed plugs a few times same,
yes i put marvel mystery oil in as a last resort to see if it would break up some carbon, after i first started it after putting in the oil, it started up normally for the fist time and idled normal for the first time for about 10 minutes then died and then went back to the way its been acting

havent checked spark, whats an easy way to?

4g63<13b · Postby **4g63<13b** » Mon Aug 20, 2012 9:14

oh also the bounces for the rear are like 75 40 40 and for the front its like 50 30 30, huge variations between one big number and two little ones for front and rear housing

VRx8 · Postby **VRx8** » Mon Aug 20, 2012 9:14

Did you took the valve out of the tester?

Try to use seafoam, sometime seals get stuck because of the carbon build up. Oil helps building compression, you may have a stuck seal and when the oil burns off you loose compression because of the stuck seal. I recommend running seafoam a few times and be ready for lots lots of smoke!!

I refuse to believe you engine is blown lol. Unless you has a big detonation witch it would've shit the apex seals out the exhaust lol. Another thing you can do is get an inspection camera from harbor freight and take the exhaust manifold off then take a look at the apex seals. And whats actually going to tell you the exact compression number would be a mazda compression tester or something equivelent like this http://www.twistedrotors.com/

4g63<13b · Postby **4g63<13b** » Mon Aug 20, 2012 9:14

VRx8 wrote:Did you took the valve out of the tester?

Try to use seafoam, sometime seals get stuck because of the carbon build up. Oil helps building compression, you may have a stuck seal and when the oil burns off you loose compression because of the stuck seal. I recommend running seafoam a few times and be ready for lots lots of smoke!!

I refuse to believe you engine is blown lol. Unless you has a big detonation witch it would've shit the apex seals out the exhaust lol. Another thing you can do is get an inspection camera from harbor freight and take the exhaust manifold off then take a look at the apex seals. And whats actually going to tell you the exact compression number would be a mazda compression tester or something equivelentyhe like this http://www.twistedrotors.com/

Yea that's what this one guy I know told me that's why I injected a shit ton of marvel mystery oil in and dry cranked and then let it sit for a coyple days and when I started it it started and idled normally for a few mins then stopped and started acting the same again, so I'm guessing all the oil in there made the compression good for a little, it was smokin like a mofo the whole time, I was really high in the rpms when I spun and it died, the air temps were also very high this day, does sea foam break down carbon and loosen the seal? That's what the marvel oil was supposed to do, you really think its not blown??

VRx8 · Postby **VRx8** » Mon Aug 20, 2012 9:14

Seafoam will decarbon your engine but people have different opinions on it, some say i'll mess up your engine some say is great. But to be safe you can also use water and steam clean you engine. Here is a thread that explains
http://www.rx7club.com/general-rotary-tech-support-11/water-instead-atf-decarboning-42318/

4g63<13b · Postby **4g63<13b** » Mon Aug 20, 2012 9:14

VRx8 wrote:Seafoam will decarbon your engine but people have different opinions on it, some say i'll mess up your engine some say is great. But to be safe you can also use water and steam clean you engine. Here is a thread that explains
http://www.rx7club.com/general-rotary-tech-support-11/water-instead-atf-decarboning-42318/

Hmm where can I get seafoam? And what do I do to use it just inject it in and dry crank?
I got to figure this out this week! I have a trade deal I'm talkiong to this guy about and I sure as hell don't want to if my motors actually good? it was wanting to over heat that dayf as well had to pull over to let it cool alot , can a slight overheat do any damage as far as compression goes? And would it have for sure blown out the apex seals if it were blown? Or can it have the apex seals still in tact with low compression?

4g63<13b · Postby **4g63<13b** » Mon Aug 20, 2012 9:14

Also if this means anything, when it first happened and it wouldn't start for like 10 mins when I did finally get it to turn over it blew a super fat amount of white smoke out for like a min like blew out!

chickenwafer · Postby **chickenwafer** » Mon Aug 20, 2012 9:14

4g63<13b wrote:Hmm where can I get seafoam? And what do I do to use it just inject it in and dry crank?
I got to figure this out this week! I have a trade deal I'm talkiong to this guy about and I sure as hell don't want to if my motors actually good? it was wanting to over heat that dayf as well had to pull over to let it cool alot , can a slight overheat do any damage as far as compression goes? And would it have for sure blown out the apex seals if it were blown? Or can it have the apex seals still in tact with low compression?

You can get Seafoam at Autozone. I usually recommend it as a last ditch attempt to potentially save a motor. It can sometimes do more damage than good. I would recommend distiller water first.

To use seafoam or water, you just start up the engine and hook up a vacuum hose to a nipple on the UIM, drop the hose in the Seafoam or water container, hold rpm at 3000, and let the engine vacuum suck it in.

Apex seals aren't the only seals in the engine...you could have a bad side seal, corner seal, flattened apex seal, corner seal, or side seal springs, etc. Most of these failures will drop compression on a single face, whereas apex seal damage will drop compression on at least two faces.

That's why you use the piston tester, remove the Schrader valve and watch for even consistent bounces. Don't pay attention to overall compression numbers.

My new Rx7 R1

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