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Search found 59 matches

by Nut124
Sun Jul 12, 2020 2:12 pm
Forum: Engine Tech
Topic: Tired rod bolts - inconsistent torque development?
Replies: 4
Views: 108

Re: Tired rod bolts - inconsistent torque development?

If your talking 1800 rod bolts your book is wrong. Or your looking at the 2000 engine rod bolt torque. They run a bigger bolt and nut. Factory 1756cc rod nuts tighten to 36ftlb! You have prob started pulling the heads off them at that torque value. I've seen it many times. Look around the head of t...
by Nut124
Sun Jul 12, 2020 10:31 am
Forum: Engine Tech
Topic: Tired rod bolts - inconsistent torque development?
Replies: 4
Views: 108

Tired rod bolts - inconsistent torque development?

I found one rod bolt in my Fiat twincam not developing torque as expected when adding torque in 5lbs increments. I replaced those two bolts and they felt "firmer." The replacement bolts are from a factory original block. The book calls for 53 ft lbs. I went in 5 lbs increments from 30 to 50 then 3 l...
by Nut124
Sun Jul 12, 2020 7:03 am
Forum: Engine Tech
Topic: Unequal IVO & IVC events
Replies: 33
Views: 863

Re: Unequal IVO & IVC events

It helps to draw the timing circle, like the one attached. In cam timing math, the origin of the numbers is assumed to be as follows: IVO: Deg BTDC IVC: Deg ABDC ICL: Deg ATDC EXO: Deg BBDC EXC: Deg ATDC ECL: Deg BTDC Duration is VO +180 + VC. ICL is Duration/2 - IVO. ECL is duration/2 - EVC. In you...
by Nut124
Sat Jul 11, 2020 10:00 pm
Forum: Engine Tech
Topic: Unequal IVO & IVC events
Replies: 33
Views: 863

Re: Unequal IVO & IVC events

I have a query, based on a hunch on the degree wheel. If - for example - the degree wheel was not centred on the crank nose, but offset. Do you think there is a possibility that it would consistently observe correct TDC and show correct numbers on and around that area of the wheel BUT, on the oppos...
by Nut124
Sat Jul 11, 2020 9:24 pm
Forum: Engine Tech
Topic: Unequal IVO & IVC events
Replies: 33
Views: 863

Re: Unequal IVO & IVC events

I got IVO @ 4° ATDC and IVC @ 38° ABDC So with a duration of 222 I am getting there, right? Are we concentrating on the duration because of my incompetence with measuring and reading a cam card? lol You guys were right, I wasn't including the lash. I am so grateful for the help. In the UK, there is...
by Nut124
Fri Jul 10, 2020 8:47 am
Forum: Engine Tech
Topic: Piston ring side (axial) clearance - higher than spec?
Replies: 10
Views: 382

Re: Piston ring side (axial) clearance - higher than spec?

There have been many, many near and actual disasters caused by flubbed Metric/Imperial conversions (or lack thereof...). One I really like (probably because of the alliterative name) is The Gimli Glider, an Air Canada 767 that in 1983 was fueled in litres instead of gallons and ran dry mid-flight: ...
by Nut124
Wed Jul 08, 2020 1:58 pm
Forum: Engine Tech
Topic: Piston ring side (axial) clearance - higher than spec?
Replies: 10
Views: 382

Re: Piston ring side (axial) clearance - higher than spec?

Never mind, I made a dumb mistake. I was using a metric feeler gauge and misread it as inches. The 6 thou clearance was actually 0.06mm or 0.0024".

All is good.
by Nut124
Wed Jul 08, 2020 12:40 pm
Forum: Engine Tech
Topic: Piston ring side (axial) clearance - higher than spec?
Replies: 10
Views: 382

Piston ring side (axial) clearance - higher than spec?

My new pistons and rings show axial clearance much higher than shop manual and google. Top ring: 0.006, Middle: 0.007, Oil ring: 0.005 Is this a problem? If so, how much so? Not much I can do about it. The piston that came out of the block had top ring clearance at 0.010. These are OEM(?) cast alu p...
by Nut124
Fri Jul 03, 2020 9:54 am
Forum: Engine Tech
Topic: Cutting seats with Neway cutters - 1st experience
Replies: 9
Views: 476

Re: Cutting seats with Neway cutters - 1st experience

Now that you've cut the seats, lap a couple of valves and check concentricity again. I always had issues with this. I put it down to the expandable pilot though. Tapered are better. The tapered pilots felt very solid. After cutting, I checked the seats w layout fluid using the method explained by J...
by Nut124
Thu Jul 02, 2020 10:42 pm
Forum: Engine Tech
Topic: Valve guide interference fit: Bronze vs cast iron guide?
Replies: 27
Views: 902

Re: Valve guide interference fit: Bronze vs cast iron guide?

... Guide to bore measured with micrometer and ball gauges is 0.04- 0.05mm in/ ex. I run same on both cast and bronze guides. Maybe a little loose, but I know they wont seize at that. This engine runs 10.8:1 and it gets pretty hot, so better safe than sorry. When I use a ball gauge I get guide ID r...
by Nut124
Thu Jul 02, 2020 5:13 pm
Forum: Engine Tech
Topic: Cutting seats with Neway cutters - 1st experience
Replies: 9
Views: 476

Re: Cutting seats with Neway cutters - 1st experience

Don't on the whole rate them, they'll get the job done in a fashion, more of a diy tool, but they're ok for topping and tailing seats if you mostly use stones and get into the aluminium on non-ferrous heads OP ..... didn't it maybe occur to you to practice on the other 'scrap' head you have first ?...
by Nut124
Thu Jul 02, 2020 11:23 am
Forum: Engine Tech
Topic: Cutting seats with Neway cutters - 1st experience
Replies: 9
Views: 476

Cutting seats with Neway cutters - 1st experience

I ordered Neway cutters for my Fiat twincam project. 45/30 and 75/15. A 60 cutter is coming today. I cut the seats and the top cuts plus some 75 in the throat. Waiting for the 60 cutter to reduce seat width. I had to cut quite a bit going to valves that are 1-1.5mm bigger than stock and the OEM seat...
by Nut124
Tue Jun 30, 2020 11:28 am
Forum: Engine Tech
Topic: Valve guide interference fit: Bronze vs cast iron guide?
Replies: 27
Views: 902

Re: Valve guide interference fit: Bronze vs cast iron guide?

AC, thanks. That looks awesome!

My Neway cutters are arriving tomorrow. How did you fit the 44mm valves? New bigger seat inserts? My seat inserts measure just over 43mm OD.

How much stem to guide clearance are you running?
by Nut124
Mon Jun 29, 2020 10:55 pm
Forum: Engine Tech
Topic: Reaming bronze valve guides
Replies: 5
Views: 308

Reaming bronze valve guides

Had my first experience reaming bronze valve guides today. This is a Fiat twincam aluminum head in which I drove the new guides. The reamers are K-Line bronze guide finish reamers, HSS. I reamed by hand with some gear oil. A few observations: - Reaming by hand was hard and slow,but was totally OK wi...
by Nut124
Sat Jun 27, 2020 9:56 pm
Forum: Engine Tech
Topic: Trouble getting the correct rings - What is going on?
Replies: 25
Views: 1288

Re: Trouble getting the correct rings - What is going on?

For any Fiat Twincam builders, the Total Seal custom quote # is #487836. These are stainless AP rings with a top inside bevel cut, like OEM. Not cheap. I fitted them into the 84.4mm bore. There was a few thou of overlap. I filed them to 0.011 gap to be checked and finished later in better light and ...