gaijin_rokurunner wrote:Bad news unfortunetly the engine blew on the dyno today but made 252hp and 164 ftlbs torque at 9000 before it went boom...Sandy at the shop said the lowest torque figure was 140 ftlb which is outstanding...he also said with a dry sump, longer runner intake and a little more c/r this thing would of made 280hp range bo problem he was very impressed...anyhow we suspect incorrect valve to piston clearence in the number 2 cylinder as one of the valve hit a piston over and over till it snapped which in turn tore up the piston and other valves...heading to the shop tomorrow to see the damage...they are investigating if its a part problem which would mean coat to rebuild is out of my pocket or builder error which they would cover everything free of charge...called Zeke down at Ferrea and he told me the valves i have are top of the line before titanium and are not made to break but bend and that fact that one broke means it hit the piston continuously till it snapped again meaning inproper valve clearence...anyhow keep u posted will probably take a while to rebuild since everything is custom more then likely need a new head which will require a whole new port and valve job as well as flow benching then if the cylinder wall is trashed a whole new block...no fixing 83mm bores... On a good note made more hp then the f20 and f22 as well as a FA so my money is well spent in my book....pictures to come

Good luck on the future.... 164#/ft is pretty good.

Besides the piston to valve clearance, I'd also check the valve springs... one reason the Atlantics go over 10,000 is because the valve springs are more than capable (dual), and it seems odd that one piston was machined incorrectly... or one valve was mis-seated. It seems more likely that a spring was not up to the task... floated... and BOOM.....

Ok first let me correct the numbers posted yesterday......engine was only revved to 8500 rpm at 8600 it committed suicide and the numbers at 8500 were 249hp and torque peaked at 155 ftlbs at 7300 rpm...... now this is still with a rich A/F mixture and 32 degrees of timing....final tune will have 37 or 38 degrees like the atlantics and a leaner A/F mixture they were just being safe getting it all the way up to the max redline which will be 9500 then adding timing and playing with the A/F mixture until they were comfortable prior to the final power run....Now the carnage....yeah looks pretty bad but could of been a lot worse and good thing is its all fixable...and the shop is covering it since it was their over-site during the build....the determination of the issue...CP cut the relief pocket angles improperly and when QRE cut the reliefs deeper they didnt check that so all 8 exhaust valves were rubbing on the wall of the relief half way down....its very minimal but enough to bend all 8 and one must of got tired of being pushed around and blew its top...literally.. anyhow QRE is going to weld up the combustion chamber to fix it...ordered a new piston today and pulled all the valves and sent them to Ferrea for inspection and replacement..im assuming 8 exhaust and 3 intake valves will be needed. Once the piston is back the reliefs will be properly cut on all 4 pistons and sent back to swain to be coated again. once back everything assembled and we can do a short break in and pick up where we left off...so im guesstimating a 2 month process as CP stated 3-4 weeks for one damn piston. Im disappointed the engine blew but i rather it do it at the shop then in my car....that would of sucked and the damage would of probably been worse on the good side im happy with the numbers and hope to squeeze a few more ponies out once its all back on the dyno and has the final mapping.

Dan the valve springs are good to go they are actually a spring Ferrea did up for suzuki moto gp...they fit the 20v perfectly just required a seat and new retainer....thats a 15000 rpm engine so it definitely not an issue there.

Can see that the valves were hitting all the pistons... impressed with how long they held up in that environment. Good luck, and it seems like you/they found the cause.

decided to bump c/r up to 14.1 since the engine is apart and invested in a Hy-tech header....the bill keeps getting bigger is there no end to spending money on these damn cars and engines !....

You are the only guy who is optimistic about his engine blowing up! Haha
It sucks that it blew up but seems like you are going to make it even cooler next go 'round!
I can only imagine...

RuizXIII wrote:You are the only guy who is optimistic about his engine blowing up! Haha
It sucks that it blew up but seems like you are going to make it even cooler next go 'round!
I can only imagine...

I would be if I didn't have to pay for the repairs, too.

Yeah dont have to pay for anything since it was their error ...i did buy a hytech header so i ended up spending money anyways lol

Good Luck!

Thanks Orange Rocket...what are u building now i see u sell alot of parts but also buy alot?

Maaaan that's such a bummer dude. Good luck with the rebuild.

gaijin_rokurunner wrote:Thanks Orange Rocket...what are u building now i see u sell alot of parts but also buy alot?

I need to sell my extra parts to go next project. haha

It's seems like your piston tops are 0.3mm to 0.5mm higher than the deck.
1)Quicksilver decked too much for the piston you made?
2) CP mis design the piston pin height?
3) piston dome wasn't hi enough so, used thin gasket to increase compression ratio.
many reasons I can think of

Anyway, if you ever going to re-make whole set of pistons, I would suggest you to make longer rod as well.
CP can make shortest piston pin height for 22.5mm with 3 rings.
5.5 AG has too much pressure to the side wall.
Oh, One more, You might want to use Longer Valve guides.

I can't wait to see next post!

No the block has 0 deck height i just think its the angle of the picture that looks like that...I sent cp an original HKS piston from the 5ag kit as well as the stock 20v piston which at 83mm and 1mm head gasket made it 12.2:1 c/r then the did a thin head shave to get 12.6:1. There is nothing wrong with the short block everything was done properly. Quick silver has been building 4ages before hasselgren, Elite and just about as long as Loyning so they know what they are doing. As far as the side walls the block has been cemented half way up the waterjackets so there is no worry about pressure on the side walls...the whole incident was a simple mis calculation of the valve pocket angle on the deep side thus the edge of the valves hit mid way down...which is why they are covering the cost to fix it. I dont think longer rods are a good idea for the 5ag due to the already longer stroke...the pin has already been moved up far where the pistons already use three rings...also i chose to use the same dome height as the stock piston because of the shape of the combustion area which is very flat compared to the 16v...i think the setup will be fine once the rebuild is done and the reliefs are corrected...the hp made already suggests a good build since nobody has made that much on a 20v to date and it wasnt even tuned 100% when it blew. Once its all done with the changes made and the new header i pedict the mid to high 260s at 9500...anything over 250 is satisfactory to me ...tecarts 7ag 20v only makes 200hp and thier 5ag 20v in Toshiki Yoshioka Team Droo-p AE86 only made 230hp...

Wow I have to come over to Club4ag more often this is way cool, thanks for the build thread
I have a 5AGZE so what makes a 5.5AG?
The term is piston side loading and that’s what orange rocket is referring to it has to do with bore to stroke ratio
My HKS crank was 3.265 stroke instead of 3.267(83mm) so it was a little short of 83MM
My pistons came from Wiseco and the ring package gets pretty tight (I use 18mm pin Carrillo rods)

Looking forward to the next dyno results

5.5ag is 83mm bore 83mm stroke..i dont think when u get into the .000 area it technically matters or makes a difference as its so minuet its mathematically the same. As far as side loading...my skirts are a lot shorter then stock and have also been coated to reduce that friction plus as i show in my thread my block has been cemented which strengthens all 4 cylinders tremendously. A lot of people dont do that when they bore to 83mm which puts them at risk especially if their block is not bored or honed properly....mines was all done at operating temp which reduces wear on the cylinder walls where as people who bore and hone their engines at room temp see extensive wear on the cylinder walls and rings at operating temps and the cylinders change in shape due to heat. My pistons are CP and incorporate a different design then Wiseco...should be a couple weeks before we are up and running again...CP is slow making pistons 3-4 weeks for one...and have to get a few valves made also...

gaijin_rokurunner wrote:5.5ag is 83mm bore 83mm stroke..i dont think when u get into the .000 area it technically matters or makes a difference as its so minuet its mathematically the same. As far as side loading...my skirts are a lot shorter then stock and have also been coated to reduce that friction plus as i show in my thread my block has been cemented which strengthens all 4 cylinders tremendously. A lot of people dont do that when they bore to 83mm which puts them at risk especially if their block is not bored or honed properly....mines was all done at operating temp which reduces wear on the cylinder walls where as people who bore and hone their engines at room temp see extensive wear on the cylinder walls and rings at operating temps and the cylinders change in shape due to heat. My pistons are CP and incorporate a different design then Wiseco...should be a couple weeks before we are up and running again...CP is slow making pistons 3-4 weeks for one...and have to get a few valves made also...

same here....

just as an inquiry... are the suzuki valves similar mass to yours? I'm sure Quicksilver, and Ferrea know what they are doing, I was just wondering outloud.

Not sure about suzuki but Zeke at Ferrea said they are simular to the yamaha motorcycle 5 valves in size..which makes sense since the head is yamaha made...my valve springs are a variation of moto gp suzuki springs with a bew retainer and seat to fit the 20v head

gaijin_rokurunner wrote:There is nothing wrong with the short block everything was done properly.

Except, apparently, piston to valve clearance.

gaijin_rokurunner wrote:the whole incident was a simple mis calculation of the valve pocket angle on the deep side thus the edge of the valves hit mid way down

This is easy to check with plasticine. I'm rather surprised a shop you tout as being as good as they are made such an amateur mistake.

Better luck next time.

Dont think I ever posted pictures of my brake setup ....the front calipers needed rebuilding when I purchased the car so I decided to upgrade to the FC3S setup, Steel lines front and back and rebuilt the rears with project mu pads..had to grind some of the fins off the top of the calipers to fit the rims im currently using....dont think it applies to all 15 inch rims but the barrel design of mines required it

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Sold my Header and bit the bullet for one of the very expensive but top notch Tri-Y Hytech headers from John at Hytech......never knew this but John worked for Quick Silver Race engines long time ago....he and Sandy are actually really close!!! Still had to pay full price haha but this design is based off the Formula Atlantic design just re-bent to fit the AE86 platform...Thanks to Billy Andrea for being the first person to get one made opening the door for others....John has a Jig setup so you dont have to take your car there for a custom build

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Customers custom made car at the shop....pretty cool setup ....Erik one of the engine builders and tuner who been working there for 18 plus year said his dad will be driving the car is some upcoming SCCA competition for the customer to try and spark interest in others possibly purchasing one

Setting up the s2000 gauge cluster.....what a pain in the ASS! all the wiring is done...I think well at least what features apply to the AE86....took the JSP panel and put some 3m textured carbon fiber vinyl on it...cut out 2 holes for my EGT gauge and my Oil Pressure...should look good when im done. Bought a custom carbon fiber HVAC delete from Carbon Fiber Collections in Hawaii to fit all my Omori gauges...looked good but fitment kind of sucks so Im debating if im going to use it now....cant fit the stereo surround under it in properly...so might ditch it if i can trim it properly!

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blast for the past

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I think you two are both doing great work!

Thanks Zenki....its hard being a Consumer!!!

Finished my rear end up....added my revolver traction brackets, and installed the N2 panhard support bracket which bolts to the frame and supports the side to side pressure put on the factory panhard mount....these things can crack and are a pain to reweld...In the future I will install a Watts link setup similar to the one pictured but SS Works makes one that actually bolts on instead of welding the mount to the center of the diff housing.

after 10 years of storage....original OEM stickers have a home