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Search found 1949 matches

by Truckedup
Sat Sep 21, 2019 7:52 am
Forum: Engine Tech
Topic: Theory of 4 valve poly quad cylinder heads.
Replies: 92
Views: 2550

Re: Theory of 4 valve poly quad cylinder heads.

4vpc wrote:
Sat Sep 21, 2019 5:02 am


With respect he just comes across as another guy with an opinion in that video.
Because it's somewhat relavent, I would be interested in your opinion on the topic ...
by Truckedup
Fri Sep 20, 2019 6:52 am
Forum: Engine Tech
Topic: Theory of 4 valve poly quad cylinder heads.
Replies: 92
Views: 2550

Re: Theory of 4 valve poly quad cylinder heads.

Not sure where that is measured at though. You could always email Kevin Cameron. Yoshimura, Dan Crower, Honda, YEC (Yamaha), all advertise some racing camshaft numbers if that will help. [/quote] On two valve Ducati's ,cam timing is checked at one millimeter, .040..I suspect the new engines are the...
by Truckedup
Thu Sep 19, 2019 2:07 pm
Forum: Engine Tech
Topic: about a Nitro cackle engine
Replies: 8
Views: 655

Re: about a Nitro cackle engine

Guys run 98 % nitro in fuel class land speed racing bikes..Most of these are N/A vintage engines..Many use modified carbs that literally just pour in the nitro...Obviously it takes some expertise..They are started on alcohol I believe...They use shorter larger diameter pipes than a gas engine...It d...
by Truckedup
Fri Sep 13, 2019 7:13 pm
Forum: Engine Tech
Topic: Theory of 4 valve poly quad cylinder heads.
Replies: 92
Views: 2550

Re: Theory of 4 valve poly quad cylinder heads.

they arent making any higher BMEP than what was done 15-20 years ago so why would they have issues on pump fuel when they pulling around a low mass, there is also a time factor the knock which works in favour of high rpm. two (2) inlet valves 34mm feeding a tiny cylinder like on the ductaui youd ho...
by Truckedup
Fri Sep 13, 2019 3:22 pm
Forum: Engine Tech
Topic: Theory of 4 valve poly quad cylinder heads.
Replies: 92
Views: 2550

Re: Theory of 4 valve poly quad cylinder heads.

Ducati has spent a lot of time and work on it to make a 4.5” bore work at 13,000rpm+, on pump gas, and a single plug. That said, Ducati has going down in bore size for improved combustion characteristics. Ducati has gone to a V4 in their top of line bike.... Yep. A lot of reasons why, but part of t...
by Truckedup
Fri Sep 13, 2019 12:35 pm
Forum: Engine Tech
Topic: Theory of 4 valve poly quad cylinder heads.
Replies: 92
Views: 2550

Re: Theory of 4 valve poly quad cylinder heads.

hoffman900 wrote:
Fri Sep 13, 2019 10:39 am

Ducati has spent a lot of time and work on it to make a 4.5” bore work at 13,000rpm+, on pump gas, and a single plug. That said, Ducati has going down in bore size for improved combustion characteristics.
Ducati has gone to a V4 in their top of line bike....
by Truckedup
Fri Sep 13, 2019 6:52 am
Forum: Engine Tech
Topic: Theory of 4 valve poly quad cylinder heads.
Replies: 92
Views: 2550

Re: Theory of 4 valve poly quad cylinder heads.

I mean, bolt on Coyote's are making 500 whp on regular pump fuel. People are going 9's in Coyote stock (sealed factory stock engines). Making 700 hp from a Coyote is not hard. The aftermarket frequently makes two mistakes: 1. Deleting VVT, the Coyote's biggest advantage 2. Improperly degreeing afte...
by Truckedup
Wed Sep 11, 2019 7:40 pm
Forum: Engine Tech
Topic: Theory of 4 valve poly quad cylinder heads.
Replies: 92
Views: 2550

Re: Theory of 4 valve poly quad cylinder heads.

A lot of this is why I think performance on the 4 valve conversion heads suffer, just lack of knowledge of how these heads work. Would love to see someone rip off a modern Sport bike head (like a Ducati twin, with a 4.5” bore) and apply it to a pushrod V8 shortblock. Obviously it would cost a fortu...
by Truckedup
Tue Sep 10, 2019 5:10 pm
Forum: Offtopic Forum
Topic: New Old Cancer Cure?
Replies: 52
Views: 3487

Re: New Old Cancer Cure?

To much concentration on the those who died...Millions have have survived for years or even cured...Many going into cancer treatment have other health problems made worse by the stress and strong treatments..... I'm faced with a high mortality rate Esophageal cancer...Recent advancements have have g...
by Truckedup
Tue Sep 10, 2019 2:17 pm
Forum: Engine Tech
Topic: Tight lash camshaft questions
Replies: 31
Views: 1402

Re: Tight lash camshaft questions

About 15 year ago I had a tight lash cam reground on a new stock core for a vintage GMC 302 inline powered 37 Chevy PU street truck I had...It was done by the late Lazer Cams owner supposedly to get as much duration as possible from a regrind..It was .005 and .007 hot lash I believe ,stock was about...
by Truckedup
Mon Sep 09, 2019 4:51 pm
Forum: Engine Tech
Topic: Theory of 4 valve poly quad cylinder heads.
Replies: 92
Views: 2550

Re: Theory of 4 valve poly quad cylinder heads.

The "poly" heads are used instead of variable cam timing ?
by Truckedup
Mon Sep 09, 2019 8:26 am
Forum: Engine Tech
Topic: Theory of 4 valve poly quad cylinder heads.
Replies: 92
Views: 2550

Re: Theory of 4 valve poly quad cylinder heads.

There's quite of bit of information on the Internet from a Google search...Maybe start there?
by Truckedup
Sun Sep 08, 2019 10:17 am
Forum: Engine Tech
Topic: Freezing tri metal bearings with Liquid Nitrogen
Replies: 24
Views: 960

Re: Freezing tri metal bearings with Liquid Nitrogen

One Factor is you don't know the actual aluminum alloy, does sand cast or die cast or forged or plate aluminum all expand the same? I believe it's a decision based on actual expereince, some of which has been expressed here....
by Truckedup
Sun Sep 08, 2019 8:07 am
Forum: Engine Tech
Topic: Freezing tri metal bearings with Liquid Nitrogen
Replies: 24
Views: 960

Re: Freezing tri metal bearings with Liquid Nitrogen

I can say from expereince that heating cast aluminim bike cases to 212 F will let a 3 inch diameter roller bearing with a .002 press fit fall out on it's own or a slight blow from a drift....There's been some disagreement on heating hotter than 230F or so and possible effects on the aluminum that is...