Engine Rebuild

Assemble the engine with the oil that you are going to run. Coat the cam and lifters with cam lube. I don't know what cam you are using... flat tappet or roller , but use cam lube with the flat tappet and install new lifters as they are a cheap investment. If you are using a roller just lube with engine oil. I would recommend priming the engine in the stand and before start up. If you installed a new flat tappet cam... Make sure you break the cam in properly!!! Take your time and make sure things are right and you should be O.K.

I'd get new lifters. Micks right about the break in. If you're using a flat tappet cam ensure the oil you're using has ZDDP in it and prime it. Check to ensure if fires the first time. Keep it around 2000 rpm for the first 10 minutes or so.

Mark's (Husker) advice is on the mark. ZDDP is a friction modifier that has been slowly removed from gasoline engine motor oil each time the SAE specifies a new oil standard, because it coats the catalyst in catalytic converters rendering it useless, not a good thing for a manufacturer that is mandated by the government to provide a 100,000 mile warranty on an emissions system. The reduction of ZDDP in oil is why there are so many problems with ruined cam lobes/lifters on flat tappet camshafts, and why the big 3 switched to roller lifters in their OHV motors.

A straight weight oil has a more sheer resistant molecule than a multi-viscosity oil, therefore I recommend straight 30 weight if its available to you. Oils designed for diesel engines still contain ZDDP because they are not equipped with catalytic converters. Therefore the best oils you can purchase for yor flat tappet OHV V8 are Shell Rotella T 30 weight, or Chevron Delo 400 30 weight. Most auto parts stores only seem to carry the 15W40 multi-viscosity version of these oils, but they are available in single 30 weight grade as well, and if you look around you should be able to find it. I purchase Rotella T in 30 weight grade at Wal Mart.

On the subject of your lifters, in is NOT advisable to run a used flat tappet lifter on a cam lobe or in a lifter bore that it was not broken in on, therefore I advise you to play it safe and purchase a new set of lifters.

your friend on the DTBB

Here's a question while we are on the subject. If you run a flat tappet cam that has already been broke in... Do you have to worry about breaking it in, the second time? I have heard, but never done...that the surface of the cam is hardened enough after breakin that it would not require a second breakin, even with new lifters. Urban Legend or not?

Urban legend.

there are 3 variables, the camshaft, the lifters, and the lifter bores in the block (this affects how the lifter sits on its lobe). Change any of the 3, and a break-in will be required. Breaking-in a cam doesn't harden anything, the cams are hardened during manufacturing. What does hopefully happen during break-in is a good layer of ZDDP is left on the lobes.

By the way, the lifter "foot" & camshaft lobe are splash lubricated, which is why we run the motors at elevated rpm to break them in, more oil is splashing about.

My advice for anyone building a motor is to switch to a hydraulic roller cam if at all possible.

Your friend on the DTBB

George,

Your advice is to go to a hydraulic roller cam. What is involved with switching to one? Can you use the same type of cam bearings? Do you have any break-in time? Is it just a matter of installing it and away you go? I understand that you have to use a "retro fit" kit. Does this involve drilling the block? Do I have to change the pushrods? I am at the stage now where I have just had two flat tappet hydraulic cams go flat, one after five mins and one after ten mins after doing everything right, checking valve lift, spring bind, etc and now am so fed up that I am going to use a hydraulic roller but have never used one before and want to get it right the first time. Any advice for me and the rest of the forum? I have been advised to use Comp Cams part number 32-431-16 hydraulic roller cam with a lift of 566 on a Pantera equipped with 4 48IDA webers and 180 headers, bored 30 over, KB Hypereutectic pistons, PJ gear drive, reworked rods, oil accumulator, oil cooler, and MSD 7al2 ignition. Thoughts on this?

Thanks, Steve

Steve, I'm switching to a roller valve train after trashing my newly rebuilt engine. Comp recommended I use the 32-451-8 due to the gear ratio and the fact its a manual trans. The lift (578) and duration (230) are a bit higher than the 32-431-8. The operating range is a bit higher also, 2500-6000 vs 2000-5500. I'm putting in a stroker kit (396) and am using Aussie 2V heads.

Steve,

there is no "breaking-in" a roller cam like there is for a flat tappet cam. The main reason I make this recommendation is because of the ZDDP issue; with a roller cam it is a non-issue. However the roller cam is also superior technology, capable of running more agressive lobe profiles & lift while maintaining drivability and reliability, than possible with a comparable flat tappet cam.

I believe your camshaft problems could have been alleviated if somebody had gotten to you with the advice to use an oil containing ZDDP. There is also an issue these days with the quality of the lifters, as many are sourced from China. Many independent cam grinders source their own lifters, so they can provide their customers with domestic manufactured lifters.

There are 2 choices in the retro-fit roller cam market:

1) Crane cams uses a steel billet camshaft and special tie-bar style roller lifters.

2) Competition Cams uses an iron camshaft and Ford OEM style lifters. This is the less expensive of the two choices, but requires drilling the block in the lifter valley to install the Ford holder that keeps the dog-bones in place.

I recommend the Crane Cams camshaft & lifters if there's budget for it. The Crane lifters are a far superior lifter. Comp Cams has also began marketing such a tie bar style lifter just recently, but I haven't read anywhere that they have compatible cams on the market for their new lifters. Comp Cams tie bar lifters are more expensive than Crane's. There have been issues with the CompCams retro-fit system using the Ford OEM style lifter. The lifter in some engine blocks rides too high in the lifter bore, even though their camshafts are ground with a reduced base circle dimension. This exposes the oil slot on the side of the lifter when the lobe pushes the lifter upwards. Its simple to see if you ran the motor this way oil pressure would be lost by such a condition.

With either choice, some of the considerations involved include:

1) a replacement distributor drive gear made of a material compatible with the camshaft material

2) springs compatible with the camshaft profile & lift

3) do not attempt to use OEM valves, retainers or keepers

4) use roller rocker arms, they do not need to be adjustable, bolt down roller rockers are OK

5) use new push rods of the proper length, it is always best to custom fit & custom order push rods. The push rods need to be heavy wall 5/16", or 3/8" diameter, as the more agressive lobe profiles and stiffer springs will create flexing of a standard 5/16" push rod.

6) Piston intake valve reliefs cut deep enough for the cam profile & lift

The best advice I can give, is to go to a Cleveland "wise" engine builder and let him assemble a kit for you, spec out a cam to meet your requirements, have the cam custom ground, etc. I would like to recommend Mark McKeown of MME Racing in Maryland. You'll find his prices will run $50 to $100 more than if you try to roll your own. This is a bargain if you consider the experience you are buying, the confidence you'll have knowing your kit was put together by an expert, and the fact you'll have a camshaft that is better suited to your application than an off the shelf cam can ever be (especially considering you are running Weber carbs).

There are several old topics in this (engine technical advice) forum with posts by Dan Jones and myself discussing the particular details of roller cam installation in much more detail. This will at least get you thinking, and help you start your way towards the goal.

Your friend on the DTBB