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Search found 2195 matches

by modok
Wed Oct 07, 2020 11:02 pm
Forum: Engine Tech
Topic: Honing 2 stroke cylinders
Replies: 11
Views: 477

Re: Honing 2 stroke cylinders

Definitely j63 for single stage finish.
I'd think a plateau finish should work better, but I did a LOT of them like that and people like it.
by modok
Wed Oct 07, 2020 10:52 pm
Forum: Engine Tech
Topic: Honing 2 stroke cylinders
Replies: 11
Views: 477

Re: Honing 2 stroke cylinders

2 strokes don't have chromoly bores, they have nikasil plated aluminum cylinders, or an iron liner pressed into an aluminum jug. if you are working with nikasil, it is very different from an iron sleeve. Moly 2000 chrome-moly iron along with Moly 2000 iron are the most common iron sleeved material ...
by modok
Mon Oct 05, 2020 8:06 pm
Forum: Engine Tech
Topic: "Cocked" rod bolts
Replies: 9
Views: 676

Re: "Cocked" rod bolts

I would guess it has been re-sized. Check length.

I agree they "should" not be re-sized, but I do lots of things that "should" not be done. sorry. :P
people have different opinions on the matter, and that's fine.
by modok
Mon Oct 05, 2020 3:28 am
Forum: Engine Tech
Topic: Top piston ring gap - whats really required?
Replies: 34
Views: 1697

Re: Top piston ring gap - whats really required?

The idea that the ring and cylinder are the same temp must be wrong. Thew ring is cooled by the cylinder. In order for heat to transfer from the ring to the cylinder, the ring MUST be hotter than the cylinder. the MORE heat is being transferred, the higher this temp differential will be. so, you hav...
by modok
Tue Sep 29, 2020 10:44 pm
Forum: Engine Tech
Topic: Are clearances actually tighter now?
Replies: 25
Views: 1290

Re: Are clearances actually tighter now?

Tighter is not always better. In the 60's, 70's a lot of bearing clearances and skirt clearances were aimed near the minimum, because the engineers had a general expectation that they would wear looser, because that's what used to happen. But all along, as materials, and lubricants and filters, and ...
by modok
Tue Sep 29, 2020 1:00 pm
Forum: Engine Tech
Topic: Worn rings, end gap and blowby
Replies: 32
Views: 1208

Re: Worn rings, end gap and blowby

You forget a very important thing; how the ring fits in the groove. The ring lands of the pistons become wider and tapered and rounded. The more wear.... the more the ring has to TWIST and bend to seat between beat out groove and tapered/ovaled cylinders, ultimately causing the ring surface to be ro...
by modok
Mon Sep 21, 2020 8:31 pm
Forum: Chassis / Suspension / Body
Topic: 54 chevy kingpin boss help please
Replies: 9
Views: 188

Re: 54 chevy kingpin boss help please

A little exercise is good for you. :P
If I had to do them more often I'd like to get an adapter to use the Rod honing mandrels in the ck-10.
by modok
Mon Sep 21, 2020 8:18 pm
Forum: Engine Tech
Topic: Are clearances actually tighter now?
Replies: 25
Views: 1290

Re: Are clearances actually tighter now?

Compared to the average car engine of 30 years ago, Do the newest engines have tighter bearing and piston clearances? And If true, is this possible because of more precise machine work? pistons yes, hyper-eutectic alloys and better skirt designs. Certainly pistons are better and cheaper than ever b...
by modok
Sun Sep 20, 2020 8:31 pm
Forum: Chassis / Suspension / Body
Topic: 54 chevy kingpin boss help please
Replies: 9
Views: 188

Re: 54 chevy kingpin boss help please

The best way is hone the axle bore for the tightest fit possible. Ream or bore to within maybe .002- .005" short of size and hone from there. You can even use a slight press fit, the main thing being that the kingpin can be pressed through without scraping it up. Should be hardened. I worked with so...
by modok
Sun Sep 20, 2020 8:25 pm
Forum: Engine Tech
Topic: Difference between IDA & IDF Webber Carbs?
Replies: 35
Views: 1151

Re: Difference between IDA & IDF Webber Carbs?

Generally the venturi should be between 75-86% of carburetor bore so 36 IDFs could use a 27mm venturi, which is actually HALF the size of a 38mm venturi So they DO make carburetors "small enough" 8 small throats might be a great idea for fuel distribution, but maybe not flow. The wall friction of 8 ...
by modok
Wed Sep 16, 2020 7:32 pm
Forum: Engine Tech
Topic: Difference between IDA & IDF Webber Carbs?
Replies: 35
Views: 1151

Re: Difference between IDA & IDF Webber Carbs?

4 IDA carbs on an IR intake would be sized right for somewhere around 500hp

4 IDA carbs on a plenum would be sized for around 1500hp
Not enough velocity to function
You would need to use two IDAs, not four. Or four of the smallest IDFs
by modok
Wed Sep 16, 2020 12:58 am
Forum: Engine Tech
Topic: Difference between IDA & IDF Webber Carbs?
Replies: 35
Views: 1151

Re: Difference between IDA & IDF Webber Carbs?

"that they will be mounted on a Holley 300-275 tunnel ram"

That's not a good idea. Why would you even do that. I really want to know
by modok
Tue Aug 25, 2020 7:47 pm
Forum: Engine Tech
Topic: Sleeve Flange To Counterbore Clearance?
Replies: 4
Views: 310

Re: Sleeve Flange To Counterbore Clearance?

I agree,
"a few thou per side" is exactly what came to mind.
by modok
Sun Aug 23, 2020 6:28 pm
Forum: Engine Tech
Topic: Single cyl for head development use,,balance problems.
Replies: 21
Views: 657

Re: Single cyl for head development use,,balance problems.

If the engine and it's mountings are heavy and strong (rigid) enough then the vibration is not really important.
90 degree twin should be a lot smoother than a single. A twisted crank v8 is basically 4 v-twins connected for even firing.... as far as balance is concerned.
by modok
Sun Aug 23, 2020 2:52 am
Forum: Engine Tech
Topic: Single cyl for head development use,,balance problems.
Replies: 21
Views: 657

Re: Single cyl for head development use,,balance problems.

if you want to use a v8 block....maybe, a pair of pistons, the other would just be along for the ride to make it into a 90dgree v twin.
Balance the crank with one bobweight OR make collars to bolt on the other crank throws for balance and to block the oil holes also.