New user here, got into Hill Climb & Auto X-ing a FJ powered Legends car. 1349cc (Wiseco pistons, Carillo rods, Lighten crank) Water Cooled, and converted to EFI
Interesting project.
What ECU are you using? What TB's?
A Hank Scott water cooled block I assume?
What headwork and cams?
Quote from: fj1289 on February 04, 2025, 08:02:37 AMInteresting project.
What ECU are you using? What TB's?
A Hank Scott water cooled block I assume?
What headwork and cams?
The Hank Scott one's that have came through here were billet but they were not finned like that. Maybe someone modified it, his ports were similar if I recall.
The thunder roadster water blocks were cast. I think that might be a Baby Grand race car water cooled block.
Hope the oil rings on your 82mm Wiseco pistons work better than mine did....then again, probably not an issue at WFO on a race engine, but definitely an issue on a street engine. Upon closed throttle deceleration, the vacuum and poor oil ring seals sucked up a quart of oil every 800 miles.
Love to hear more about your EFI...
Quote from: Pat Conlon on February 04, 2025, 02:02:33 PMHope the oil rings on your 82mm Wiseco pistons work better than mine did....then again, probably not an issue at WFO on a race engine, but definitely an issue on a street engine. Upon closed throttle deceleration, the vacuum and poor oil ring seals sucked up a quart of oil every 800 miles.
Love to hear more about your EFI...
Now where have I read about those rings.. :empathy3:
Quote from: Pat Conlon on February 04, 2025, 02:02:33 PMHope the oil rings on your 82mm Wiseco pistons work better than mine did....then again, probably not an issue at WFO on a race engine, but definitely an issue on a street engine. Upon closed throttle deceleration, the vacuum and poor oil ring seals sucked up a quart of oil every 800 miles.
Love to hear more about your EFI...
Yep still have those rings in my 1350r. Sucked oil from day one. Someday have to go the route you did Pat. Or maybe use one of the 2 billet bigbore cylinders that I have. I really would like to know about the feul injection too.
Quote from: Pat Conlon on February 04, 2025, 02:02:33 PMHope the oil rings on your 82mm Wiseco pistons work better than mine did....then again, probably not an issue at WFO on a race engine, but definitely an issue on a street engine. Upon closed throttle deceleration, the vacuum and poor oil ring seals sucked up a quart of oil every 800 miles.
Love to hear more about your EFI...
Pardon my ignorance but I'm not familiar with the rings you fella's are referring to. Is it the type of ring pack or the quality of the rings?? Example...are they the thin XA rings or XC or XG. I've use all of these rings packs in the past and can attest to The XA rings....especially the oil rails....to be a PITA to install and get to seal in less than perfect bores. I can also recommend not using the XA's in any turbo or supercharged bike engine.
Hi Mike, good to hear from you.
I can't recall the ring pack used on the HSR short skirt 82mm pistons. I do know that the oil ring tension was the suspected culprit. The pistons could have removed and the ring lands deepened to accept a thicker oil ring with more tension but I went ahead and converted over to the long skirt 83mm Ross pistons...all is well since.
What's good on the track is not necessarily good for the street.
Here is an old post on the then new HSR short skirt pistons vs. the traditional JE pistons...
Quote from: Pat Conlon on October 28, 2010, 07:52:41 PMOk so here are the pictures, courtesy of Randy@RPM:
First the standard JE 1250cc pistons:
(http://fjowners.com/gallery/1/49_28_10_10_6_29_52.jpeg)
Now the new 82mm Wisecos, look at those short skirts and wrist pin:
(http://fjowners.com/gallery/1/49_28_10_10_6_31_04.jpeg)
Wrist pin difference:
(http://fjowners.com/gallery/1/49_28_10_10_6_33_43.jpeg)
No word yet on pricing.....
Thanks for the quick reply Pat....hope life is treating you well! The short and abbreviated skirt circumference could cause problems with long strokes and larger bores....a lot of piston rock. The rings look like XC which are pretty standard for aftermarket bike street engines. That being said 4 stroke MX pistons are basically a nail head with XA rings and they seal well. Same goes for F1 engines. :yes:
I do believe the HSR are XC.
Ring packs do keep getting better and better. We are running 1mm top, 1mm 2nd rings, and the oil control rings are only 2mm tall, in the new LS7 440ci, stroker with 4.185" pistons, 14.07:1 compression, engine we are building for Ryan's Miata.
I think it is more the Wiseco piston design, as Mike mentioned. The 1319 and 1297 Wiseco kits with that same design we have heard of oil consumption problems from a few different engine builders.
Quote from: RPM - Robert on February 05, 2025, 03:53:47 PM....The 1319 and 1297 Wiseco kits with that same design we have heard of oil consumption problems from a few different engine builders.
IIRC Aviation Fred had the 1297 Wiseco's in his engine, the largest piston sleeves that could fit in the stock (unrelieved) engine case. I wonder about his oil consumption?
What say you amigo?
Just looked at Hank's kits he is using/selling XG ring packs and the Andrew's kit that Fred is using are XC ring packs. Both Wiseco slipper skirt pistons, so if Fred's isn't using oil then it looks like a ring pack problem, if it is using oil maybe the skirt and piston rock contribute.
No issues with the full skirt Ross for sure. The LS is getting custom Ross pistons made currently.
Quote from: RPM - Robert on February 06, 2025, 10:55:10 AMNo issues with the full skirt Ross for sure.
Yes, I'm very happy with my RPM engine with the Ross pistons, very happy.
Came off of a 4K mile tour last spring and used very little oil, about 1/4 quart.
Engine runs like a top....
Robert, you guys staying normally aspirated on the LS?
Quote from: Pat Conlon on February 06, 2025, 11:25:38 AMQuote from: RPM - Robert on February 06, 2025, 10:55:10 AMNo issues with the full skirt Ross for sure.
Robert, you guys staying normally aspirated on the LS?
Yes sir. Hoping be around 750-800 hp and maybe a touch over 700-750ft lb torque to the wheel. We have around 20% parasitic drivetrain loss after adding the Winters quick change.
Bought a 525hp LS3 crate motor and made 419hp/390 ft lb to the wheel with a FAST 102mm. Put a 4150 Wilson Manifold t body and a single plane high rise and that bumped it to 489hp and 424 ft lbs.
This LS7 was in a Formula drift car and made 660hp and 590 torque with a stock corvette intake with 4.125" pistons and 12.5:1 compression. We are hoping with the new higher .700" lift cam, increased bore to 4.185", higher compression, and the 13+% gain from a better intake we will be up there.
Sounds like a hairy E85 beast of a Miata Robert.
I wonder if tires will be the limiting factor?
You can only get so much width under that Miata.
There ain't a whole lot of Miata left in that thing! Pretty much full on race car :i_am_so_happy:
Chris, the unibody and chassis are all miata along with all the suspension pickups points and geometry. The drivetrain is the only swapped parts.
Pat, we put some over fenders on it and stuffed an 11 inch Hoosier A7 in there. Not many tire options in a 15" tire. Going to an 18 would require extensive cutting of the back.
Car is down to 2100lbs with 4 gallons oil and 8 gallons of fuel. No driver. 52% front and 50% cross weight
750hp/2,100 = 2.8 lbs per hp....normally aspirated, dead nuts reliable, that's gonna be a handful, and a hoot.
Now....Back to your regularly scheduled program.
Quote from: RPM - Robert on February 07, 2025, 12:03:38 PMChris, the unibody and chassis are all miata along with all the suspension pickups points and geometry. The drivetrain is the only swapped parts.
Sweet! I thought it had been front and back halfed.
Be cool to see it run in anger!
Quote from: fj1289 on February 07, 2025, 05:30:55 PMQuote from: RPM - Robert on February 07, 2025, 12:03:38 PMChris, the unibody and chassis are all miata along with all the suspension pickups points and geometry. The drivetrain is the only swapped parts.
Sweet! I thought it had been front and back halfed.
Be cool to see it run in anger!
Nope just sheet metal cut away and tubing added to beef everything up. The old car the front end would sag when you jacked it up. So adding all the extra tubing was necessary to make it a bit more rigid.
We also used 1.75" tubing instead of 1.5" for safety/speed reasons. The weight of the car we could "legally" use 1.5" but peace of mind is worth its weight in gold sometimes.
Quote from: RPM - Robert on February 07, 2025, 10:16:01 PMWe also used 1.75" tubing instead of 1.5" for safety/speed reasons. The weight of the car we could "legally" use 1.5" but peace of mind is worth its weight in gold sometimes.
Robert, don't forget your front and back hubs. Front wheel bearing failures are common on track Miata's
https://www.miatahubs.com/product-page/na-nb-miata-front-enduro-hubs
Nicely done!
Fully agree - a tad extra weight is worth the extra strength and rigidity.
Quote from: Pat Conlon on February 08, 2025, 10:00:50 AMQuote from: RPM - Robert on February 07, 2025, 10:16:01 PMWe also used 1.75" tubing instead of 1.5" for safety/speed reasons. The weight of the car we could "legally" use 1.5" but peace of mind is worth its weight in gold sometimes.
Robert, don't forget your front and back hubs. Front wheel bearing failures are common on track Miata's
https://www.miatahubs.com/product-page/na-nb-miata-front-enduro-hubs
Ryan's friend runs a small business called bro-fab.com we have been using his hubs for several years with no issues. However, with the g forces we are pulling we check them after every event when doing our nut and bolt. AIM data shows lateral g a touch above 3 and inline under braking around 1.5 deceleration is around acecel .7 g
A 3g lateral load is impressive.
Makes my pencil neck ache just thinking about it.
When you get a chance, post some progress pictures for us.
Here is an in car from this Saturday. On old tires but still putting down a pretty good lap. For comparison the nascar cup series last qualified the full track in 2019. Kyle Larson was on pole with a 1:34.598. Ryan ran a 1:35.02 on work out tires. The SCCA spec Miata record is a 1:54.933
https://youtu.be/AZzVuzMgE-Q?si=eZ0ZtQw_UopqmKPs
THAT's what splitters are for! :rofl:
I've been intrigued by the watercooled blocks, especially since I've noticed quite a few electric water pumps being used in other similar applications.
interesting!