Engine build questions

[jbs007]

I’m finally getting time to mess with the Scout again and would like to gain a little power and reliability out of the engine. It is a 1979 Scout II with a 345/727. I am looking at getting the fuel injection kit for it and figured it would be a good time for a few other upgrades. I am looking for some advice and help getting all the right pieces.

First off, this engine has been rebuilt twice in the past and I am not sure if the block or heads have ever been decked. I need a way to figure this out because I would like a slightly increased compression ratio (to roughly 8.5:1) even with the thicker-than-stock head gaskets that are available today. To accomidate the new gaskets, how much should be decked, from the block or the heads, and how do I tell how much (if any) has been decked already?

I would like to get some head work done to include porting the exhaust a little and strong valve springs. I also want to get the tri-y headers. The heads are in good condition. Can I send them to you to have this work done on them? Is there anything else you would recommend be done to the heads at this time?

I’d like to get a slightly more aggressive cam and am leaning toward the split duration isky based on reading other forums. What would you recommend for this application?
For headers, how do tri-y and standard type differ in operation?

Thanks for the help!

 

[ihpartsjeff]

Pretty lengthy question here so it will be hard to address all your needs. Have you searched this forum yet for answers to some of these questions? Some has been gone over in the past like determining if the heads/block have been machined before.

For the cylinder heads although we are not a machine shop we can do the exhaust porting. Honestly I would rather have your machine shop handle all the rest of the head work as all we would be doing is passing it on to ours. I don't have pricing for this as it is not something we do everyday.

As for the camshaft there are several cams you can choose from and it all comes down to how you plan on using the vehicle. Any of these cams can be used with fuel injection but the closer to stock you keep things the easier it will be to get the fuel injection dialed in. I know bill at hfi has tuned some IH engines before with the split duration isky cam(including mine) so I would not hesitate to recommend this cam grind as it is a touch more aggressive than stock but not too radical.

As for headers a 4 into 1 header is for higher rpm's while a tri-y is better for lower rpm's and torque. Since these IH engines aren't hi revving machines it is typically better to go with tri-y's.

 

[jbs007]

I have the engine apart now and realized I need to get some gaskets, so I'll be ordering a full gasket set today or tomorrow.

I also need lifters for my new cam and was wondering if it makes a difference which kind I get. I see yall have 2 lifter offerings: one from comp cam and another with no brand. What is the difference between them? Is there any reason to get one over the other for my build?

Also, in my quest to attain a desired compression ratio, I am wondering if my cylinders have ever been bored out before. The pistons in my engine have the following stamped on them

u^p z2:3
391931-c2

any way of finding out what the diameter of these is? I haven't been able to find any info on it.

Thanks again IH Parts America!

 

[ihpartsjeff]

I have the engine apart now and realized I need to get some gaskets, so I'll be ordering a full gasket set today or tomorrow.

I also need lifters for my new cam and was wondering if it makes a difference which kind I get. I see yall have 2 lifter offerings: one from comp cam and another with no brand. What is the difference between them? Is there any reason to get one over the other for my build?

Also, in my quest to attain a desired compression ratio, I am wondering if my cylinders have ever been bored out before. The pistons in my engine have the following stamped on them

u^p z2:3
391931-c2

any way of finding out what the diameter of these is? I haven't been able to find any info on it.

Thanks again IH Parts America!

Sorry for the late reply. Just got back in town and somehow the guys missed your posting.

For the lifters as far as I can tell there is no reason to get one over the other. We listed the comp lifters separately since we do stock them as they come with the master cam kits that we offer.

For the pistons if they were oversized somewhere on them would be stamped .020, 030, 040 or 060. You can always grab a micrometer and measure them as that is the most accurate way plus measuring them will show any signs of a problem like out of round or collapsed.