Working over a motor

[Dutch Rutter]

REALLY !! They didn't want your money??? What the heck is wrong with these people??

Yep. I was totally willing to wait the three weeks but they straight up turned me away. I guess the "dying industry" in Oregon here has too much work to justify taking on more. I might have to drive it out of state just to get my block tanked, new cam bearings, freeze plugs and a hone.

 

[75gmck25]

Sorry to hear about the machine shop issues. Its ironic to hear politicians talk about wanting to give work back to local industry, and then finding that nobody locally wants to do mechanical work for you. Its not attractive for young kids out of high school to learn mechanical skills, even though the demand (and income) will continue for years.

Back to your original cam question. The key point is that the cam profile and lift needs to be matched to head flow and compression if you want to have good performance. Since you plan to used better aluminum heads, you can go for a little more cam and still have a decent torque band. What you want to avoid is sticking with a low compression OEM block and heads (probably only 8.0-8.2 compression), and then trying to use a cam with duration that is 220+ @.050 (or more). It will have that rump-rump sound, but suck for low end torque and gas mileage. That is why the GM 350/290HP crate engine is usually a bad choice - too much cam for the compression and head flow.

For example, I swapped heads and was able to get compression up to about 9.4, which works well with the 213/217 @ .050 cam I selected. I considered going for more cam, but this one seems to be a better match for a heavy truck. It has a little bit of cam sound at idle, but no noticeable lope.

Bruce

 

[DoubleDingo]

That is jacked-up! A crate engine, what if you don't want a crate engine, which you clearly don't.

 

[Dutch Rutter]

Sorry to hear about the machine shop issues. Its ironic to hear politicians talk about wanting to give work back to local industry, and then finding that nobody locally wants to do mechanical work for you. Its not attractive for young kids out of high school to learn mechanical skills, even though the demand (and income) will continue for years.

Back to your original cam question. The key point is that the cam profile and lift needs to be matched to head flow and compression if you want to have good performance. Since you plan to used better aluminum heads, you can go for a little more cam and still have a decent torque band. What you want to avoid is sticking with a low compression OEM block and heads (probably only 8.0-8.2 compression), and then trying to use a cam with duration that is 220+ @.050 (or more). It will have that rump-rump sound, but suck for low end torque and gas mileage. That is why the GM 350/290HP crate engine is usually a bad choice - too much cam for the compression and head flow.

For example, I swapped heads and was able to get compression up to about 9.4, which works well with the 213/217 @ .050 cam I selected. I considered going for more cam, but this one seems to be a better match for a heavy truck. It has a little bit of cam sound at idle, but no noticeable lope.

Bruce

This i great info, thank you! Since this will be going into a daily driven k series which will occasionally go offroad and tow a small to medium trailer and load occasionally I know that I should stay with an RV type cam for more low end torque. But from what I'm thinking (which is very most likely wrong as I know nothing about cams) with a basically stock motor a RV cam would be a great choice. But I feel with better flowing heads, intake, and exhaust I could benefit from a slightly larger cam (without going too much) and I still would be able to keep my low end torque and pull.

This is where I start getting lost a bit. I was told that you should match your cam RPM range with your intake RPM range for best effect. I do know that the compression will play a big role into what I can take advantage of. and then I will also have to make sure my springs will be suitable for the cam lift as well. I was also told that torque converter stall (mine is a 2400rpm) and transmission plays a part in what thump stick you want as well, but I feel that is more torwards having the power where you will be using/wanting it in the RPM range.

Since I'm not building a drag or race motor I am most likely getting into the weeds too much, I'm really hoping to build this thing properly to where it will be reliable but still taking advantage of the better flowing heads, intake and exhaust. I was also struggling with the designation of cams, I know back in the day it was RV, RV2 (what I have now) then there were 3/4 race, 1/2 race and full race. But everything I see now lists the cam specs. For instance the Lunati voodoo I've been eyeballing mainly because it shows an RPM range of idle-5000. This shows an advertised duration of 250/256, lift 437/454 and a separation of 112 Would this be worth while for me or should I be looking at something different? granted I should get through some of the assembly process so I can get an idea of my compression before finalizing anything.

 

[Dutch Rutter]

That is jacked-up! A crate engine, what if you don't want a crate engine, which you clearly don't.

This what I cant understand either. Since I have all of the parts and most are in good to usable shape. I'm looking at $900-$1200 for parts alone. so unless the machine work will run me $4000 there is no way that I will be near the price of a comparable crate motor which let's be honest probably wont have the same quality, and will most likely leak or give me some kind of headache down the road.

Let's say I went with a crate, lasts through the warranty then a cam bearing goes now it needs its own machine work. So what then? just replace the whole thing with another brand new crate.

 

[4WDKC]

best option is to call a cam manufacturer or Chris Straub about cam recommendations.

 

[4WDKC]

This what I cant understand either. Since I have all of the parts and most are in good to usable shape. I'm looking at $900-$1200 for parts alone. so unless the machine work will run me $4000 there is no way that I will be near the price of a comparable crate motor which let's be honest probably wont have the same quality, and will most likely leak or give me some kind of headache down the road.

Let's say I went with a crate, lasts through the warranty then a cam bearing goes now it needs its own machine work. So what then? just replace the whole thing with another brand new crate.

yes, our societyi s gravitating towards a replace it instead of repair it culture. That machine sop probably doesnt like to mess with used parts because of their liability and or people just bring them bad stuff and bad mouth them. Doing stock rebuilds with used parts is cost effective for you but benefits them very little, if you needed parts that they could sell you it adds more to their profit.

 

[Dutch Rutter]

best option is to call a cam manufacturer or Chris Straub about cam recommendations.

Thanks! I'll keep that in my back pocket for now. First things first I gotta call another shop up. Also I fully agree with you on the change in culture. Since it is a big NAPA shop they would rather sell me something. I'm sure one of the two small shops I found will be willing to do some work for me. Hopefully good work but I guess I'll take the chance and see.

 

[Backfoot100]

Finding a good shop to do machine work is like finding a unicorn.
I built a 383 and it took me weeks to find a shop. I called at least a dozen of them. You better know what you're talking about when you call them but you find out in literally a minute or less if you want do business with them. There's a lot of morons out there that call themselves machinists.
Finally found a guy almost two hours away but he was awesome. I wanted to do all my own assembly and I ended up having him verify all bearing clearances and assembling the pistons to rods. I did all cleaning, painting, preassembly, final assembly and startup.
I would never buy a crate motor knowing what I know now.
Stick with it. You'll find somebody if you have the patience and not on a short time table.
Good machinists can have at least a few months backlog but they're well worth the wait.

 

[4WDKC]

If you are still looking go to local hang outs or race tracks and ask guys what machine shop they recommend. Its a double edged sword because you will find a good shop builds lots of racers engines usually keeping them busy and requiring you to wait for your turn. I had mine rebuilt by a shop that did alot of dirt racer engines it has been trouble free and built the way I want it.. also dont rush them, the same shop that built mine was rushed by someone else and the engine had problems.

 

[Dutch Rutter]

Thanks all! I actually one last night. Totally by accident, me and the wife drove to a old drive up AnW dinner for dinner. Lucky for me it was their cruise in night. Ended up chatting with a bunch of people who were looking at my truck instead while standing with their hotrods. They all pointed me to the same guy. He is a retired engine builder and machinist by trade. He now runs a shop out of his garage and does all of his machine work himself. Talked to him extensively and felt really good about it. Guessing I struck gold because he does hot rod motors but primarily does full restorations so he says a lot of the work he has is waiting on cars to be done with paint and such things. Looking like I'll be getting all of my parts back from him within the next 2 weeks.

He checked everything over very well and said he did not see any red flags or anything out of place. I'll be looking at getting the block cleaned new cam bearings, freeze plugs, and honed. he'll check all of the bores which he says look fine. He'll turn my crank for $120 check the journals out. Open the heads and inspect them (kind of the only parts in question) and even recommend me a cam kit based on my wants and the parts I'm giving him. I told him I am wanting to do the assembly, one of those fun project me and the old man enjoy doing together.

I'm pretty excited to be having him do the work for me, and it sounds like a great fit.

 

[Dutch Rutter]

Guess I should post an update to this thread.

Got the motor back from the machine shop last Friday. Had them do the basic work along with replacing one out of round connecting rod, one bent exhaust valve, and springs in the heads.
After talking to him a little he recommended a speed pro cs-1013r cam and lifters.

Fairly basic I am sure but probably will fit my needs perfectly

• 2000-4500 RPM Range,
• 288 intake/298 exhaust Adv Dur,
• [email protected] 214 intake/224 exhaust,
• Valve Lift 443 intake/465 exhaust,
• Lobe C/L 112

The last weekend I was able to clean all of my parts up, install main bearings, rear main, crank, cam, rod bearings, and 7 of 8 pistons (broke one ring during install) The new ring set along with a bunch of other new parts are being delivered today and this weekend I'll be continuing assembly.

 

[Dutch Rutter]

Getting this thing together finally. I ran into a question though, should I put in a windage tray? I've never ran one before and really dont know if it'd be beneficial or just more of a headache.

Fyi if I need one I'm looking at the Canton TR-20-910 A screened type for $54 and their stud kit for an additional $56

Here is a shot of the beastie, currently upside down to keep junk out before we have a nice day to paint the block and press forward with assembly.

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[dvdswan]

IIRC, windage trays are helpful for racing, high revving engines. Idea is to reduce the drag weight of the crank from slapping the oil in the pan.

 

[Dutch Rutter]

IIRC, windage trays are helpful for racing, high revving engines. Idea is to reduce the drag weight of the crank from slapping the oil in the pan.

Thanks for the quick reply!! I feel this is right on the money. And i am not in a position to NEED one, as this engine wont be a super power house or any kind of a high rev. Therefore I believe the stock baffled pan should be adequate.