Tow Truck Engine

[OlSnort2]

I have a 440 Holmes wrecker body mounted on a 74 Chevrolet C30 chassis. Current setup is a Carolina Machine Engine High Torque 350 longblock, (whatever that consists of) with an Edelbrock Performer intake, 1406 Carb, HEI distributor and small headers. Sling wrecker is PTO driven off a SM465 transmission, has a 4.56 gear and 31 inch tires. I have no idea what it turns at cruise, there is no tach in the truck. I really dont use the sling on the road, but it is functional and comes in handy to move stuff around, hence the need for a good idle. I do have a Reese hitch and use it to tow a trailer with whatever project I have, sometimes but not often on the interstate. Probably 85% of the time its empty, just running around . The old 350 did an adequate, but not outstanding job, but its shot and needs replacing.
I've got an old Modified motor thats sitting in the floor Im thinking of trying to de-tune to replace it with. 406 with Dart Sportsman II's that have way too much compression for pump gas. Solid Rollercam, way too big for a truck motor.
My thoughts are to use the basic shortblock with different heads and possibly stick with the solid roller setup. I just dont know if its possible to get that small of a core and have a cam ground that would work. I wouldnt think of starting from scratch and building a solid roller for a truck for the street, but the parts are bought and paid for and currently doing nobody any good.
Basic specs on the shortblock are deck height .005, Eagle 6" H beam rods, forged crank, 4-bolt splayed caps, JE forged flat top pistons, nothing fancy. When we were planning the motor we wanted to keep it mild and turn around 6800 at the end of the straightaway, but often turned 7400. It wasnt a Clements motor, but a little better than what was being spouted as a claimer motor in 1999-2000. Way out of date today, and definitely not a crate 602.
Best I can figure a 72cc aluminum head with 180-195 cc runners should give me around 10:1 compression and flow enough for some good bottom end torque.
I didnt actually build the motor, so I dont have assembly notes, Im working off a 25 year old memory here.
Ive ran a bunch of flat tappet stuff in the past, both solid and hydraulic, but am thinking I would like to go back roller, whether I keep the solid or shell out the money and go hydraulic.
Thoughts?

[Monza355]

Your best bet for using your existing 406 engine would probably be using 75cc AFR heads 180cc and a decent hydraulic roller camshaft with your solid roller lifters. It’s not the optimal set up but it works just fine. It will make tons of low end power and still be cheaper than buying or building another engine.

[bobmc]

the current cost of hyd roller lifters is absurd, just not acceptable for a budget build, for a low use engine your current lifters should work fine with a street type solid roller lobe, maybe a cam expert can tell from the cam core you have if it is feasible to regrind or you might be able to sell it

[frnkeore]

I would change out the solid roller. A new cam will be +/- $650. For about 1/2 that cost, you can go to a HFT cam and lifters.

For your purpose, you don't need the ramps or lift that the roller can give.

[Walter R. Malik]

I have a 440 Holmes wrecker body mounted on a 74 Chevrolet C30 chassis. Current setup is a Carolina Machine Engine High Torque 350 longblock, (whatever that consists of) with an Edelbrock Performer intake, 1406 Carb, HEI distributor and small headers. Sling wrecker is PTO driven off a SM465 transmission, has a 4.56 gear and 31 inch tires. I have no idea what it turns at cruise, there is no tach in the truck. I really dont use the sling on the road, but it is functional and comes in handy to move stuff around, hence the need for a good idle. I do have a Reese hitch and use it to tow a trailer with whatever project I have, sometimes but not often on the interstate. Probably 85% of the time its empty, just running around . The old 350 did an adequate, but not outstanding job, but its shot and needs replacing.
I've got an old Modified motor thats sitting in the floor Im thinking of trying to de-tune to replace it with. 406 with Dart Sportsman II's that have way too much compression for pump gas. Solid Rollercam, way too big for a truck motor.
My thoughts are to use the basic shortblock with different heads and possibly stick with the solid roller setup. I just dont know if its possible to get that small of a core and have a cam ground that would work. I wouldnt think of starting from scratch and building a solid roller for a truck for the street, but the parts are bought and paid for and currently doing nobody any good.
Basic specs on the shortblock are deck height .005, Eagle 6" H beam rods, forged crank, 4-bolt splayed caps, JE forged flat top pistons, nothing fancy. When we were planning the motor we wanted to keep it mild and turn around 6800 at the end of the straightaway, but often turned 7400. It wasnt a Clements motor, but a little better than what was being spouted as a claimer motor in 1999-2000. Way out of date today, and definitely not a crate 602.
Best I can figure a 72cc aluminum head with 180-195 cc runners should give me around 10:1 compression and flow enough for some good bottom end torque.
I didnt actually build the motor, so I dont have assembly notes, Im working off a 25 year old memory here.
Ive ran a bunch of flat tappet stuff in the past, both solid and hydraulic, but am thinking I would like to go back roller, whether I keep the solid or shell out the money and go hydraulic.
Thoughts?

In the early 2000's I re-built 9 engines for a car hauling company to use in their Highway Chevrolet trucks pulling a tag along trailer.
They were throttle body injected engines so they had to still be able to use the original ECM with only a few parts substitutions.
They were 350 engines with became 383 engines, using a 305HO flat tappet camshaft and the rest was pretty much stock except for using a Flowkooler water pump.
Raising the fuel pressure, (those regulators were actually in that throttle body), about 5 to 10 percent was all that was needed for good mileage with regular gasoline when pulling a trailer or not.
With a carburetor, it would be really easy but, it sounds like you have other things in mind beside towing with it.

This was an easy engine to do with great results. I originally did 2 and that company owner kept sending more.

[Monzsta]

Stay away from the cheap Amazon or ebay link bar roller hydraulics. I bought them and they have very weak springs inside. After a few years one of them stuck completely so after assessing what happened I just gave it a valve lash of .005" and ran the rest of the rockers down off the bottom a 1/4 turn.

Man, the Howards lifters I were eyeballing to replace mine have doubled in price.

[FC-Pilot]

If I were in your shoes, and not knowing all the details, I might use the sportsmans. Unless they were ported to be huge I would open up the chamber a little ( enough to lower the compression and use a thicker head gasket. Then use a good flat tappet and lifters and go with it. Those heads take a beating and not buying new heads will free up cash for cam lifters and springs.

Then again I don’t know the engines specifics so that is just a guess. Or, use the heads and use the cash on pistons that lower the compression. I would still consider the new cam and lifters though. Again, just an idea not knowing the engines specifics.

Paul

[rgalajda]

I would rebuild the 350 with the sportsman heads. The sportsman heads flow about the same as the Vortec head.

[OlSnort2]

I dug around online and found an RPM calculator, looks like 60 MPH would run about 3K rpm, 80MPH about 4000. Most of my driving around here would be closer to 2500.
I was shying away from hydraulic because the oiling to the top end was restricted, and all the small holes in the lifter valley were were either plugged or had standpipes put in them or both...I really dont remember. I'm also a little skittish when I hear about all the problems some people are having making the flat tappet stuff live now.
The Sportsman heads I have were angle cut, ported and had bigger valves put in. They are angle plug also, while the existing headers are for straight plugs. I dont want to try the thick gasket deal because that would hurt the quench . Would the existing headers work with angle plug heads? Maybe, but I dont want to try to put them on and find out the answer is no.
I sort of like the idea of the TBI 383 combo, sounds like it was a success. I wonder if the same thing could be done with a 98 Vortec in a Suburban...another project for another day.
Thanks guys for all the comments. Every day is a school day here.

[rfoll]

Flat top pistons in a 406 with a 64 cc chamber come out to the neighborhood of 11:1. A 75 cc chamber is around 10:1, still too much for towing. A 406 with piston having a generous dish and Vortec heads will move mountains and run on regular fuel. AFR heads are $2300.00.

[OlSnort2]

I had hoped maybe Mike Jones would see this and chime in on the feasibility of a small solid roller for the street. I looked at the form for ordering a cam, but it asked for a lot of information I dont have. I hate to call him during working hours without all the info I know he will want, and not be able to pull the trigger on what I want. I gotta have respect for a man's time. I have questions, he'll have questions. This way he can poke at it when or if he feels like it.
I dont know exactly where his shop is located, but best I can figure its about 1 1/2 hours from me here. I know there is Fedex and UPS, but a good road trip is not out of the question. Late 60's early 70's, it wasnt a big deal for my Daddy and my uncle to drive up to Holman-Moody to buy parts.
I do know I have looked at some of the standard stuff available and I dont see anything that I think will suit my purpose.

[frnkeore]

I figure that the best compromise, would be a 224° @ .050 SR cam lobe for what you want. The longest .020 duration lobe I could find for that .050 dur was 262°, in a SR. With a 115 ICL, you could do it with the 72cc head but,you'd have to run ~.025 deck clearance on the piston to get by with 92 oct gas.