Hello - wanted some final input before I move out my engine plan. I just dropped the block, crank and rods off at the machine shop. Should find out what it will take to clean up the bore and crank in the next couple days. Meanwhile want to make sure I start ordering parts where I can. Here are my questions:

1. I want to use Tim Meyer Pistons. (Website states that most oversize is sold out for another week or so, and no luck getting anyone on the phone). Part number is KB2347, and it says 9.4 compression with a stock 76CC head. I am planning on buying a Trick Flow Aluminium Head, (72 CC), and getting the shop to finish it. I am assuming that this will put the compression ratio up to around 9.8 to 1. Will this run on pump gas (mid-grade). Is this too much compression for towing?

2. I want to put a roller camshaft in the engine. I am looking at a Comp CAMS Magnum 270HR. Anyone have experience with this Cam? It states its RPM range is 1800 to 500, so assuming it should be pretty good for a towing truck? It looks like it needs a lifter retainer plate/kit? Is this setup reliable? I have seen other lifters where there is a linked/bar between the lifters, is that better?

3. Any other things I should consider? Anyone have something similar, and how do you like it?

Joel

 

Tim is busy and can't always answer the phone. However, he is good about returning calls if a message is left or responding to email.

As for the compression, aluminum heads pull enough heat from the top end that you can run about 1.0 more compression on the same gas as with cast iron. The engine Tim is building for me will use Trick Flow heads and will have 10.5:1 compression, and he assures me it will run fine on mid-grade gas.

On the cam, without looking at anything but the RPM range I think that is too much cam. I would want the range to be from idle up, not 1800. But, don't take my word for it - ask Tim as he builds and dynos these engines day in and day out. And then buy your heads and cam through him to compensate him for his time and knowledge. He can steer you right on both of them and has his own profiles for cams that he has Comp Cams grind and ship to you. Tim listened to what I wanted from the engine and recommended TF heads and a specific cam, so that's what we are doing. And his prices are competitive.

And, on any other things, have your shop do Tim's oil system Mod's and install Tim's cam bearings - the way his instructions say. The shop that did my machine work didn't follow his instructions, so make sure yours does. The cam bearings are a big part of his mod's and those mod's work.

 

Joel,

Sounds like you've got a good handle on things. Tim Meyer is the guy to get you where you want to go for sure.

1 - yes 9.8:1 compression with aluminum heads should be just fine. No experience personally, just a LOT of people running 10:1 or 10.5:1 on the street without problems.

2 - link-bar lifters are supposed to be better than the lifter valley "spider" because the spider can deflect at high RPM and cause power to drop off. Again no personal experience here, but at a certain performance level - the factory style spider is replaced by link-bar lifters. I don't think that cam would be too radical - the 400 is an inherently torquey engine anyway, especially with the added compression.

3 - +1 on the oiling system mods! DO NOT run a high volume pump, more likely to cause problems if you don't know what you are doing.

Have fun!

 

Have them check the blocks align bore.

 

Hello Joel,

I have been using aluminium cylinder heads for the past +/-40,000 miles, so I can comment with regard to your question 1.

My engine is a 351c with edelbrock 60cc heads (part no. 61629), KB 148-040 D cup pistons (13cc dish), zero deck height, and an Edelbrock 2172 'mild' cam. (Squish is 0.041" which is the compressed gasket height.)

The static compression ratio (SCR) is 10.12. (I can't find where I put my Dynamic compression workings )

I have been using 95 octane (South Africa), which I believe is 91 octane (USA) since the rebuild with no problems.

I expected a better fuel consumption with the new build, but had no idea it would be 12% better. Bonus !!

The 12% improvement is down to the more efficient fuel burn with the ''quench head'' etc.

The total mechanical ignition timing used to be 36 degrees but I dropped it to 28 degrees to avoid pinging. (I'm at sea level.)

The lower timing is also due to the more efficient engine.

No loss of power that I can feel, and the engine is very responsive from 0mph right up to 100mph.

I don't think you would have problems towing with an SCR of +/-9.8.

Choose your parts as a package, and not individually (I doubt you will, but had to mention it).

Food for thought :

Why choose a 72cc head with flat top pistons ?
Or, why choose a 60cc head with 13cc dish pistons ?

With regard to the cam, you might lose out on torque with an 1,800rpm to 5,000rpm range when towing, or driving normally even.

You want a cam that retains or maximises low end torque, so as Gary suggests, an idle upwards, say to 5,000rpm, would be preferred.

That said, would you feel a difference in torque with the cam you mentioned, as SDDL-UP suggests ? I don't know!

With regard to question 2, if you can justify the extra expense, by all means go with a roller cam.

I went with flats as I couldn't justify the extra price, and so far so good.

Please post up your final choices.