Question for engine builders: Timing set selection for line honed block

[turbodave231]

I am in the process of assembling an engine where the block has been line honed 2X. The stock center to center dimension between the cam and crank is 4.335. The block measures 4.328........(or .007") closer So do I order a -.005 or a -.010 timing set? The cam going in isn't anything crazy or special. Just a 208/210 hyd. flat tappet.

Which set?

Dave

 

[Mike E]

Good question. I'm currently waiting to hear back about the line bore on my block so I can order a timing set also.

This is the only valuable info I've found. timing chain/line bore blocks • Speed Talk

 

[bison]

Order a .006 and a .008 under and use whatever one fits best. I used a .010 on an engine recently.

 

[turbodave231]

Brian,

Where can I get -.006 or -.008? I have only seen .005 and .010 sets? Progear?

 

[turbolou]

no exact answer without pre assembly. My guess would be the next under size available.

 

[bison]

Brian,

Where can I get -.006 or -.008? I have only seen .005 and .010 sets? Progear?

Call mike at full throttle. He gets engine works timing sets in whatever size you need

 

[Mike E]

TA shows that they sell 2,4,6,8 and 10 under for odd fire style.

 

[Turbo-Archie]

Order a .006 and a .008 under and use whatever one fits best. I used a .010 on an engine recently.

What are you looking for in fit?
Or do you just have to have a feel for it?

..

 

[bison]

What are you looking for in fit?
Or do you just have to have a feel for it?

..

You need to have a baseline to go off of. Other than that there are instructions with it. I've ran them loose with no mechanical problems. It makes me a little nervous running hard up over 6000 rpm and heavy springs with it really loose then letting off. The chain will whip and could fail. I'd probably try an .008 under first

 

[Turbo-Archie]

Thanks for the feed back.

I ask because I pulled an engine apart that was built by a local shop. They used the Rollmaster but it was on so tight it was hard to believe. It didn't seem right.
It was just a 206 FT cam..


..

 

[SuperSix]

What is an acceptable amount of chain deflection with the Rollmaster?

Here's a crappy vid I shot after my install..

 

[NCTURBOS]

Engine Works = Rollmaster. They can be had in std.-.010. I get them from Nickels Performance in TN. My experience is that you can usually go .002 from measurement and be OK. So, I would start with the .008.


K.

 

[big reazon]

Super six mine look to have the same amount of movement.

 

[Alky V6]

There's no way of knowing exactly what undersize you're going to end up with until you start trying different sets during assembly. The perfect situation would be to have a shelf with a good range of undersized gearsets and trial fit them until you've found the one that's best.
As long as you can fit the gearset without forcing it, you're good. The chain may seem too tight (very little play), but as soon as you start the engine, play is going to start building.
Make sure you rotate the engine a few times looking for tighter sections in the chain during rotation. A chain can be tighter in some positions that other positions. Again, find the tightest spot, and as long as the gearset can be fitted at that position without forcing it, you're good.

 

[dlafont]

There's no way of knowing exactly what undersize you're going to end up with until you start trying different sets during assembly. The perfect situation would be to have a shelf with a good range of undersized gearsets and trial fit them until you've found the one that's best.
As long as you can fit the gearset without forcing it, you're good. The chain may seem too tight (very little play), but as soon as you start the engine, play is going to start building.
Make sure you rotate the engine a few times looking for tighter sections in the chain during rotation. A chain can be tighter in some positions that other positions. Again, find the tightest spot, and as long as the gearset can be fitted at that position without forcing it, you're good.

Wow... That sounds expensive.. It's going to be difficult to have a variety of timing chains at $130 a piece. Surely there has to be a better way to find out which one is best to use.

I'm just in the middle of a rebuild and will be working on my 2nd line hone with this block so I'm in the same situation. I got to find a proper set but I don't want to order 2 or 3 timing chain sets. Has anybody come up with a solution to find a close fit without just trying ones until they do.

Can you just return the ones that don't end up fitting right back to the vendors without them complaining?

 

[turbodave231]

I want to avoid buying more than one timing set. That why I measured very carefully. I made a precision ground mandrel that fits in the cam bore. (The mandrel was needed to set up the Buick block on our CNC milll) I measured the distance between the crank snout and the mandrel. That's how I came up with the -.007" measurement. I will order a -.008 set and see what happens.

Thanks for the input.