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Search found 2078 matches

by ptuomov
Wed Jul 08, 2020 1:30 pm
Forum: Engine Tech
Topic: 2 stroke for drag racing cars?
Replies: 46
Views: 8015

Re: 2 stroke for drag racing cars?

The downfall I understand to nikasil is you have do all cylinders over in event of failure. The heat process distorts whole block. I didn't know what, that's surprising. For example, we do nothing ever to those Porsche blocks in terms of mains, no line boring or anything. They measure exactly the s...
by ptuomov
Wed Jul 08, 2020 11:05 am
Forum: Engine Tech
Topic: 2 stroke for drag racing cars?
Replies: 46
Views: 8015

Re: 2 stroke for drag racing cars?

Sort of off topic, but same thinking.... For context.. A lot of the higher hp 2 strokes released by yamaha and Kawasaki around 1999-2004 were 1200 cc, 155 hp triples. Made peak power at about 7500 rpm. They had nickel silicone carbide (Nikasil) plated aluminum cylinders. Always wondered why the big...
by ptuomov
Tue Jul 07, 2020 9:31 pm
Forum: Engine Tech
Topic: 2 stroke for drag racing cars?
Replies: 46
Views: 8015

Re: 2 stroke for drag racing cars?

Gas exchange I think limits the rpm of two strokes when the bore size gets bigger, so there’s a rev limiter in there that goes down as displacement increase.
by ptuomov
Sun Jul 05, 2020 10:02 am
Forum: Engine Tech
Topic: Dyno result for the risky business Porsche
Replies: 133
Views: 24088

Re: Dyno result for the risky business Porsche

dannobee wrote:
Sun Jul 05, 2020 9:54 am
Those look pretty low in the chassis. Are you running a scavenge pump on the drains?
Yes, no other way to fit them.
by ptuomov
Sat Jul 04, 2020 10:26 pm
Forum: Engine Tech
Topic: Dyno result for the risky business Porsche
Replies: 133
Views: 24088

Re: Dyno result for the risky business Porsche

Custom cast exhaust manifolds bolted on, ready to have the turbos to be attached.
B209C997-734D-4225-85D7-B1722A7C48CA.jpeg
1187C807-2EA7-4BF3-AC03-88F27649B022.jpeg
by ptuomov
Sat Jul 04, 2020 8:28 am
Forum: Engine Tech
Topic: recognizing alusil
Replies: 12
Views: 466

Re: recognizing alusil

If you are just doing a freshen on those liners, BRM makes flex hones specifically for nikasil. I have one app that I use one on and it does give the correct finish. Opinions vary on whether anything needs to be done or should be done to Nikasil bores when pistons and/or rings are replaced. Some sa...
by ptuomov
Fri Jul 03, 2020 11:16 am
Forum: Engine Tech
Topic: Straight through mufflers
Replies: 88
Views: 3037

Re: Straight through mufflers

I had a customer who had the dreaded highway 60mph drone, it was worse after he switched to a manual 5 speed od trans which we thought had more to with how and where the muffs were mounted. Same engine I built for him, was much worse with manual than the auto ...OD was the worst, in 4th not so bad....
by ptuomov
Thu Jul 02, 2020 8:06 pm
Forum: Engine Tech
Topic: Dyno result for the risky business Porsche
Replies: 133
Views: 24088

Re: Dyno result for the risky business Porsche

Delayed video update:

by ptuomov
Thu Jul 02, 2020 7:14 pm
Forum: Engine Tech
Topic: recognizing alusil
Replies: 12
Views: 466

Re: recognizing alusil

so I guess nikasil can be applied to iron blocks and sleeves, something I was not aware of. This coming from total-seal and ptuomov. nikasil has a distinct bright appearance to it however, this looks to be DLC. Diamond like carbon coating which google is telling me has been applied to cylinder bore...
by ptuomov
Thu Jul 02, 2020 4:16 pm
Forum: Engine Tech
Topic: recognizing alusil
Replies: 12
Views: 466

Re: recognizing alusil

bentvalves wrote:
Thu Jul 02, 2020 3:23 pm
If I had to wager a bet, these bores are DLC treated.

It is like trying to hone glass.
That’s what Nikasil is like.
by ptuomov
Thu Jul 02, 2020 1:54 pm
Forum: Engine Tech
Topic: recognizing alusil
Replies: 12
Views: 466

Re: recognizing alusil

Alusil is not applied, the parent material is a high silicon content aluminum. It's a special process to hone them, I did a Youtube video showing how I do BMW V8's, using a profilometer to ensure that each step arrives at the right Ra value before moving on to the next step. I'll try to attach the ...
by ptuomov
Tue Jun 30, 2020 7:58 am
Forum: Engine Tech
Topic: Straight through mufflers
Replies: 88
Views: 3037

Re: Straight through mufflers

I own a muffler shop and I can tell you this. In your case I would adapt down to a 3 inch muffler with 2-3 inch tailpipes using the Dynomax super turbo muffler. It will sound a little quiter but more grown man sound and it breathes very well. I am a very big fan of there mufflers. I have uncapped m...
by ptuomov
Mon Jun 29, 2020 5:01 pm
Forum: Engine Tech
Topic: Straight through mufflers
Replies: 88
Views: 3037

Re: Straight through mufflers

I dont care if i loose 50 HP if I can kill the drone.Car operates 99.9% of the time from off idle to 2500 max.Cruise either in 4th on the street of 5th on the freeway is at 2000.Tom In my opinion, a key to eliminating the drone is to have many mufflers, many pipe sections of different length, and a...
by ptuomov
Mon Jun 29, 2020 12:26 pm
Forum: Engine Tech
Topic: Straight through mufflers
Replies: 88
Views: 3037

Re: Straight through mufflers

“A” would be correct, but for now it’s just a temporary exhaust system. I’m going to add a crossover of some sort, probably an X pipe My car went from true separate duals with a single straight thru muffler on both sides to this, also with straight thru mufflers, and the sound improved dramatically...
by ptuomov
Mon Jun 29, 2020 11:07 am
Forum: Engine Tech
Topic: Dyno result for the risky business Porsche
Replies: 133
Views: 24088

Re: Dyno result for the risky business Porsche

Models Dimensions Tolerances book for: 928 81, 82 Models 928 S 80, 81, 82, 83, 84 Models Engine weight (dry) Pg. 14 '81-'82 M28.09/10/15/16 245kg Pg. 17 '80-'83 M28.11/12/19/20 261kg Pg. 17 '84 M28.21/22/19/20 261kg Technical Specifications book for: 928 S Models 85, 86 928 S4 Models 87, 88, 89 Engi...