crack open new engine to port or not?
Thread Starter
Joined: May 2004
Posts: 519
Likes: 28
From: San Pedro, California
crack open new engine to port or not?
So I have decided to order a new engine from Mazda, and the only question is whether I want to break the seal to do a street port or not. I will be installing a precision 5866, and I don't care for big power numbers, just around 350whp as reliable and responsive as possible for my track car.
I like the idea of doing a straight drop in vs opening up a brand new engine, is there any downside to either choice? Or would it be smarter to run higher boost or port the new engine and run lower boost for the same power output? The main goal is rock solid reliability.
I like the idea of doing a straight drop in vs opening up a brand new engine, is there any downside to either choice? Or would it be smarter to run higher boost or port the new engine and run lower boost for the same power output? The main goal is rock solid reliability.
There might be another reason to open it. This was the last post in this thread....
https://www.rx7club.com/3rd-gen-gene...ngine-1133905/
https://www.rx7club.com/3rd-gen-gene...ngine-1133905/
If your new engine is from a rebuilder, please disregard the following.
But if by "new engine", you mean a 0 mile Mazda shortblock, many (from the mid to late 2000's at least) were tested by Mazda techs in Japan after builds without the use of 50/50 coolant, and lower coolant passages became clogged to varying degrees with rust ... and resulting overheat issues.
Yes, blocks were drained before storage, but by design, it's impossible to get all coolant out, which is why using only water for testing was extremely short sighted of Mazda techs.
If bought from Mazda, (depending on purchase date of course), I would recommend flushing it using 50/50 coolant before install, draining outflow into a clean white 5 gal container, preferably at an authorized Mazda service dealership. If any rust is in the bucket, ask for a refund or free rebuild.
It sounds like a hassle, but trust me doing it at home without a witness, will potentially complicate your life more than you could ever imagine.
I did all of the above on my own, at home, and although Mazda was entirely to blame for condition issues described,
Mazda USA did not stand tall, they just walked away, claiming it was not installed at an authorized Mazda repair facility, within 1 year.
I should have received that warranty info, but did not receive anything other than the block and shipping container and invoice.
I had heat issues within 1st 5 minutes of the 1st startup of the new burped short block. I had to pull, disassemble, clean and re-assemble the new block.
I still haven't re-installed it. It was clogged with rust along all bottom cooling passages, and no, it could not all have been flushed out.
It's too bad purchasers of these problem short blocks never organized to file a class action lawsuit against Mazda.
I suspect blocks installed or disassembled for port work shortly after purchase, were settled quietly, but some shortblock buyers were left high + dry.
If Mazda had any idea of the hardship caused for some unsuspecting buyers, without the benefit of local Mazda recognized rotary rebuilders, Mazda would hopefully have handled things differently. Many of the $1500 in support parts purchased for long block assembly can't be re-used. That makes the entire experience doubly infuriating, for those with empty wallets after purchase, on top of all wasted labor.
With any other car company, or shortblock, 100% of buyers would have enjoyed their car for the past 12 years, but my FD has been parked for 12 years and me out about $6000* US and 100's of hours of labor. The unused parts obviously have value, but time and effort lost pulling + installing block twice exceed that value, all because of a Mazda coverup. The 1995 block this new shortblock was supposed to replace, was entirely rust free in all cooling passages.
I sincerely hope you have better luck with your project !
But if by "new engine", you mean a 0 mile Mazda shortblock, many (from the mid to late 2000's at least) were tested by Mazda techs in Japan after builds without the use of 50/50 coolant, and lower coolant passages became clogged to varying degrees with rust ... and resulting overheat issues.
Yes, blocks were drained before storage, but by design, it's impossible to get all coolant out, which is why using only water for testing was extremely short sighted of Mazda techs.
If bought from Mazda, (depending on purchase date of course), I would recommend flushing it using 50/50 coolant before install, draining outflow into a clean white 5 gal container, preferably at an authorized Mazda service dealership. If any rust is in the bucket, ask for a refund or free rebuild.
It sounds like a hassle, but trust me doing it at home without a witness, will potentially complicate your life more than you could ever imagine.
I did all of the above on my own, at home, and although Mazda was entirely to blame for condition issues described,
Mazda USA did not stand tall, they just walked away, claiming it was not installed at an authorized Mazda repair facility, within 1 year.
I should have received that warranty info, but did not receive anything other than the block and shipping container and invoice.
I had heat issues within 1st 5 minutes of the 1st startup of the new burped short block. I had to pull, disassemble, clean and re-assemble the new block.
I still haven't re-installed it. It was clogged with rust along all bottom cooling passages, and no, it could not all have been flushed out.
It's too bad purchasers of these problem short blocks never organized to file a class action lawsuit against Mazda.
I suspect blocks installed or disassembled for port work shortly after purchase, were settled quietly, but some shortblock buyers were left high + dry.
If Mazda had any idea of the hardship caused for some unsuspecting buyers, without the benefit of local Mazda recognized rotary rebuilders, Mazda would hopefully have handled things differently. Many of the $1500 in support parts purchased for long block assembly can't be re-used. That makes the entire experience doubly infuriating, for those with empty wallets after purchase, on top of all wasted labor.
With any other car company, or shortblock, 100% of buyers would have enjoyed their car for the past 12 years, but my FD has been parked for 12 years and me out about $6000* US and 100's of hours of labor. The unused parts obviously have value, but time and effort lost pulling + installing block twice exceed that value, all because of a Mazda coverup. The 1995 block this new shortblock was supposed to replace, was entirely rust free in all cooling passages.
I sincerely hope you have better luck with your project !
You may consider swapping to a different apex seal vs OEM as well while your in there for longevity at higher than stock hp levels. The rxparts seals seem to take alot more abuse and dont ruin the housings as bad as some of the other "unbreakable" seals.
It's really up to you. For the power levels you're wanting to attain porting isn't a necessity. Going with better apex seals is a great idea, modern aftermarket apex seals have come a long way and can really survive detonation events better than the stock apex seals.
I'm not sure what soft parts you may need to replace if you do crack it open. In theory the water seals, dowel pin o-rings, etc. should all be reusable but you may have to replace if they tear or look to be a problem.
It would also be a good chance to check the side seal clearances, Mazda has a range that they find acceptable but I try to make side seal clearances all the same. I do .003" on side seals, I get each one exactly the same, that can greatly improve sealing and reduce blow by. I don't know how much slop they have on these new motors, though.
If it was me, I would
- Open the engine up, check side seal clearances. If some are loose, order enough side seals to replace the short ones.
- Replace stock apex seals with RX Parts. Sell stock apex seals to recoup some costs.
- Check all water seals, dowel pin o-rings, tension bolt washers for any deformation or tearing and replace if necessary
- Replace front cover gasket with metal front cover gasket (Atkins has them) if the engine doesn't already have it
- Port engine
Definitely give yourself some time to order parts. If you haven't built a motor yourself you'll need to find a shop you trust to do the work.
I know IR Performance has done this a number of times for customers.
Dale
I'm not sure what soft parts you may need to replace if you do crack it open. In theory the water seals, dowel pin o-rings, etc. should all be reusable but you may have to replace if they tear or look to be a problem.
It would also be a good chance to check the side seal clearances, Mazda has a range that they find acceptable but I try to make side seal clearances all the same. I do .003" on side seals, I get each one exactly the same, that can greatly improve sealing and reduce blow by. I don't know how much slop they have on these new motors, though.
If it was me, I would
- Open the engine up, check side seal clearances. If some are loose, order enough side seals to replace the short ones.
- Replace stock apex seals with RX Parts. Sell stock apex seals to recoup some costs.
- Check all water seals, dowel pin o-rings, tension bolt washers for any deformation or tearing and replace if necessary
- Replace front cover gasket with metal front cover gasket (Atkins has them) if the engine doesn't already have it
- Port engine
Definitely give yourself some time to order parts. If you haven't built a motor yourself you'll need to find a shop you trust to do the work.
I know IR Performance has done this a number of times for customers.
Dale
I've sold over 100 of these motors over the past few years and have yet to see any issues caused by corrosion. Yes Mazda pre-runs the motors with water, but a quick coolant change after initial breakin would flush out anything left in there. I believe the issues a few individuals experienced were from older new motors that were left to sit for several years. All the new ones I have sold have build dates within 6-8 months on average. I haven't seen any excessive rust in the new blocks.
We both install them as is, and tear many down for porting and other upgrades. Porting will improve turbo response and make it easier to meet your power goals with less boost, but isn't absolutely necessary. Better apex seals will give you insurance against detonation at elevated power levels. We use RX Parts exclusively. They are super resilient, yet do not score up the rotor housings prematurely. Engine studs are a worthwhile investment when approaching or exceeding 450 hp. You are looking at about $200 in soft seals and gaskets to properly close a new motor back up.
I have several brand new motors in stock if you need one. They are the absolute best deal to get all 100% brand new parts.
We both install them as is, and tear many down for porting and other upgrades. Porting will improve turbo response and make it easier to meet your power goals with less boost, but isn't absolutely necessary. Better apex seals will give you insurance against detonation at elevated power levels. We use RX Parts exclusively. They are super resilient, yet do not score up the rotor housings prematurely. Engine studs are a worthwhile investment when approaching or exceeding 450 hp. You are looking at about $200 in soft seals and gaskets to properly close a new motor back up.
I have several brand new motors in stock if you need one. They are the absolute best deal to get all 100% brand new parts.
Last edited by IRPerformance; Mar 6, 2019 at 01:25 PM.
Joined: Mar 2001
Posts: 31,835
Likes: 3,233
From: https://www2.mazda.com/en/100th/
+1 the current engines are pretty fresh. they seem to be making them to order, which is what you do when you have a rotary engine plant and no rotary engine car
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Thread Starter
Joined: May 2004
Posts: 519
Likes: 28
From: San Pedro, California
Thanks for all the feedback! It's a lot to think about...what do you think about just doing this to my current engine that still runs? I believe an apex seal may be chipped but it seems that compression is still good. The car starts right up and drives strong. Comparing costs, it seems that getting new housings and every associated seal already adds up to the cost of getting a new motor, so I am leaning strongly towards getting a completely new engine.
Thanks for all the feedback! It's a lot to think about...what do you think about just doing this to my current engine that still runs? I believe an apex seal may be chipped but it seems that compression is still good. The car starts right up and drives strong. Comparing costs, it seems that getting new housings and every associated seal already adds up to the cost of getting a new motor, so I am leaning strongly towards getting a completely new engine.
If you had a chipped seal it would likely idle rough, low vacuum, hard to hot start. If it just seems tired it's more likely the seals are worn down, side seals are sticking, etc. which is reducing compression, along with worn rotor housings.
A compression test will tell for sure.
Regardless, the new Mazda engines are a very good deal.
Dale
A compression test will tell for sure.
Regardless, the new Mazda engines are a very good deal.
Dale
Thread Starter
Joined: May 2004
Posts: 519
Likes: 28
From: San Pedro, California
Yep that is exactly what's happening. A rotary mechanic heard me pulling away and stopped me to tell me it sounds like a chipped seal, so that's what's prompting me to start this thread.
I was in the EXACT boat as you this time last year with oem motor having the same issue & faced with rebuilding that or going with another donor motor. I then personally picked up a new Keg from Ray C. and was dead set on just using getting that in. After some thought and waiting to get the work done, I went with the porting route (street) as I knew what my end goal target was. In the end, I did a lot of the 'might as well' stuff while the motor was out instead of spending twice down the line with future upgrades. I guess it really comes down to your TRUE goal including budget. Exactly what IRP said in post #9 was my issue & post #6 was the upgrade with studs etc based on my goals. (They also did the work)
OT, but I recall your username from way back on SF
OT, but I recall your username from way back on SF
Thread Starter
Joined: May 2004
Posts: 519
Likes: 28
From: San Pedro, California
I was in the EXACT boat as you this time last year with oem motor having the same issue & faced with rebuilding that or going with another donor motor. I then personally picked up a new Keg from Ray C. and was dead set on just using getting that in. After some thought and waiting to get the work done, I went with the porting route (street) as I knew what my end goal target was. In the end, I did a lot of the 'might as well' stuff while the motor was out instead of spending twice down the line with future upgrades. I guess it really comes down to your TRUE goal including budget. Exactly what IRP said in post #9 was my issue & post #6 was the upgrade with studs etc based on my goals. (They also did the work)
OT, but I recall your username from way back on SF
OT, but I recall your username from way back on SF
I think I am gonna go this same route as well. I fall in that trap of "might as well" way too deep every time.
I'm running a completely stock new 13B-REW block from Mazda that I put in last fall.
Couple of notes-
With just modded/ported throttle body, lightly cleaned up intake manifold runners, emissions delete, 3" downpipe, to high flow cat with muffler to 3 1/3" catback, ROM tuned ECU and 11 heat range plugs the engine is surprisingly rowdy.
Its got the slightly wandering idle to the point people comment on it, some random backfires starting it or shifting when cold, shoots a couple feet of flame on the revlimiter. Stock this engine ain't no Earth Dreams.
The engine we get is the later '99+ high hp engine. I don't know if they revised anything, but the oil pressure is outstanding. Anything over 2,500rpm and the oil pressure is right up there just under the 120psi mark where it lives.
Starts fast, tight engine. Friend commented at the last meet he never heard a rotary start that fast.
Yes, it had coolant traces in it and no rust when I received it.
Couple of notes-
With just modded/ported throttle body, lightly cleaned up intake manifold runners, emissions delete, 3" downpipe, to high flow cat with muffler to 3 1/3" catback, ROM tuned ECU and 11 heat range plugs the engine is surprisingly rowdy.
Its got the slightly wandering idle to the point people comment on it, some random backfires starting it or shifting when cold, shoots a couple feet of flame on the revlimiter. Stock this engine ain't no Earth Dreams.
The engine we get is the later '99+ high hp engine. I don't know if they revised anything, but the oil pressure is outstanding. Anything over 2,500rpm and the oil pressure is right up there just under the 120psi mark where it lives.
Starts fast, tight engine. Friend commented at the last meet he never heard a rotary start that fast.
Yes, it had coolant traces in it and no rust when I received it.
Thanks for all the feedback! It's a lot to think about...what do you think about just doing this to my current engine that still runs? I believe an apex seal may be chipped but it seems that compression is still good. The car starts right up and drives strong. Comparing costs, it seems that getting new housings and every associated seal already adds up to the cost of getting a new motor, so I am leaning strongly towards getting a completely new engine.
Buy the new donor, pull your current engine down and keep the good parts stored after vigorous clean up, inspection, and oiled/labeled in something other than a shitbox garbage bag :P It's nice to have a spare 90% complete engine, you can either build it as a spare or have a pool of parts for later.
Hell if that's the case, they need to start pushing out some brand new 20b blocks. The used market pricing has gotten ridiculous. After paying what I paid for my used block back in 2003, I'm not paying double that for a spare used block that's rusted and has broken coolant walls like mine already does.
Last edited by t-von; Mar 18, 2019 at 01:36 PM.
Hell if that's the case, they need to start pushing out some brand new 20b blocks. The used market pricing has gotten ridiculous. After paying what I paid for my used block back in 2003, I'm not paying double that for a spare used block that's rusted and has broken coolant walls like mine already does.
Last edited by dguy; Mar 18, 2019 at 08:35 PM.
Joined: Mar 2001
Posts: 31,835
Likes: 3,233
From: https://www2.mazda.com/en/100th/
Hell if that's the case, they need to start pushing out some brand new 20b blocks. The used market pricing has gotten ridiculous. After paying what I paid for my used block back in 2003, I'm not paying double that for a spare used block that's rusted and has broken coolant walls like mine already does.
Full Member
Joined: Dec 2015
Posts: 102
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From: Thessaloniki
I'm running a completely stock new 13B-REW block from Mazda that I put in last fall.
Couple of notes-
With just modded/ported throttle body, lightly cleaned up intake manifold runners, emissions delete, 3" downpipe, to high flow cat with muffler to 3 1/3" catback, ROM tuned ECU and 11 heat range plugs the engine is surprisingly rowdy.
Its got the slightly wandering idle to the point people comment on it, some random backfires starting it or shifting when cold, shoots a couple feet of flame on the revlimiter. Stock this engine ain't no Earth Dreams.
The engine we get is the later '99+ high hp engine. I don't know if they revised anything, but the oil pressure is outstanding. Anything over 2,500rpm and the oil pressure is right up there just under the 120psi mark where it lives.
Starts fast, tight engine. Friend commented at the last meet he never heard a rotary start that fast.
Yes, it had coolant traces in it and no rust when I received it.
Couple of notes-
With just modded/ported throttle body, lightly cleaned up intake manifold runners, emissions delete, 3" downpipe, to high flow cat with muffler to 3 1/3" catback, ROM tuned ECU and 11 heat range plugs the engine is surprisingly rowdy.
Its got the slightly wandering idle to the point people comment on it, some random backfires starting it or shifting when cold, shoots a couple feet of flame on the revlimiter. Stock this engine ain't no Earth Dreams.
The engine we get is the later '99+ high hp engine. I don't know if they revised anything, but the oil pressure is outstanding. Anything over 2,500rpm and the oil pressure is right up there just under the 120psi mark where it lives.
Starts fast, tight engine. Friend commented at the last meet he never heard a rotary start that fast.
Yes, it had coolant traces in it and no rust when I received it.
get 9 all around and you will be amased
Joined: Mar 2001
Posts: 31,835
Likes: 3,233
From: https://www2.mazda.com/en/100th/
Joined: Mar 2001
Posts: 31,835
Likes: 3,233
From: https://www2.mazda.com/en/100th/
I know, I meant as far as actually being able to have one delivered. Similar to the old reman'd blocks, the part was still in the system though everywhere I tried to source one wasn't able to get it. We bought a couple from Sylvain Tremblay before he bailed on speedsource so its no biggie but for a personal project it'd be nice to start from a clean slate.