22degree heads with 30degree big bore kit?

[David Jones]

You can hear it very easily. Just replace the heater tubes inside the longitudinals with a straight pipe and run the heater tubes direct from the heat exchanger horns to the longitudinal tube entry. Open the heater vents and then listen. You can then hear every little sound your engine makes.

[Ron LaDow]

Hi Juha
Ron's stuff is nice but you can get excellent results the way you do things if you don't want to do the math i suggest installing the head and measuring the combustion volume directly. you have to subtract about 2ml for the plug volume.
j

First, you sure don't need the Pre Mat tools; pretty sure John's comments refer to the ease and accuracy, which is what tools are supposed to do.
But, sorry Jacques, there is no way to fill a cylinder through the plug hole and get a reliable, 100% fill.
This is very easy to prove by a reverse test of bubbles and gravity: Fit the valves, turn the head upside down, pour water in it and try to drain it out the plug hole only (not pour it over the edges).
You can do the hokey pokey and turn yourself around all you please, and some water will remain in pockets, mostly around the intake valve.
Imagine the head upright, minus quite a few of the axis you used trying to empty it as you try to fill it 100%, and the air is going to be trapped in those pockets.
If 9.25 is what your gas, chambers and timing will tolerate, you can take the result and get 9.0 in one, 8.9 in another and so forth. Or you can guess at the remaining bubbles and get maybe 9.4 in one hole.
And that's what it's all about; Precision Matters.

[Ron LaDow]

You can hear it very easily. Just replace the heater tubes inside the longitudinals with a straight pipe and run the heater tubes direct from the heat exchanger horns to the longitudinal tube entry. Open the heater vents and then listen. You can then hear every little sound your engine makes.

The '56 Speedster has solid tubes (I think; it still has the original 'tudes). You know it when one valve is loose.

[Mike Smith]

The '56 Speedster has solid tubes (I think; it still has the original 'tudes). You know it when one valve is loose.

The Heater Operating Valves should have Silencing fitted within them
(Find original valves or buy the PRS ones fro the UK)

[C J Murray]

Ron, it is possible to measure the compressed volume of the assembled engine at TDC if done carefully but it must be done on a bench where the plug hole is vertical and some manipulation of the engine position can be done to assure that the chamber is fully "burped" of air. You can't do this on an engine stand.

Ron, here is an idea for a great new tool....a graduated canister containing 600cc of fluid with a hose and a spark plug adaptor. Bleed the fluid to the end of the plug adaptor to establish the accurate volume of the fluid at the start. The plug adaptor would also have a vent hole. Open a valve at the plug adaptor until it reaches the vent hole to measure the volume of the engine at BDC. Simple math using the swept area of the cylinder and you have a very accurate CR measurement. The tool could be marketed to all builders of all engines.

[Neil Bardsley]

Ron, it is possible to measure the compressed volume of the assembled engine at TDC if done carefully but it must be done on a bench where the plug hole is vertical and some manipulation of the engine position can be done to assure that the chamber is fully "burped" of air. You can't do this on an engine stand.

Ron, here is an idea for a great new tool....a graduated canister containing 600cc of fluid with a hose and a spark plug adaptor. Bleed the fluid to the end of the plug adaptor to establish the accurate volume of the fluid at the start. The plug adaptor would also have a vent hole. Open a valve at the plug adaptor until it reaches the vent hole to measure the volume of the engine at BDC. Simple math using the swept area of the cylinder and you have a very accurate CR measurement. The tool could be marketed to all builders of all engines.

What about the tool to get the fluid out of the cylinder afterwards?

[Ron LaDow]

Ron, it is possible to measure the compressed volume of the assembled engine at TDC if done carefully but it must be done on a bench where the plug hole is vertical and some manipulation of the engine position can be done to assure that the chamber is fully "burped" of air.

Cliff, see above.
There is no way to see if there are bubbles in there, and my test above pretty much shows there are bubbles in there.

[C J Murray]

What about the tool to get the fluid out of the cylinder afterwards?

Remove the head. This would be done before going farther than installing the cylinders which may need shimming anyway...or maybe the piston crown needs a shave.

[David Jones]

In a street engine how much in reality would be gained by measuring the volume if there is a difference of say 1 cc, then what are you going to do if the engine is otherwise running well? Is 1 cc of volume in a street engine which is less than 2% of combustion chamber volume going to make any noticeable difference? I think not. It would be a lot of work for the average owner to go to such lengths for a street engine. Seems kind of anal to me to pursue such perfection. I should add that I was that anal with my race engines but so far unless I have had to get a head refurbished I have not bothered to check cc's if a head was undamaged and all my street engines have run and idled well. Matching heads side to side is a good idea but to get more precise than 1 cc may be over achieving.
Again this is just my opinion so feel free to disagree and confuse me with more facts.

[Ron LaDow]

In a street engine how much in reality would be gained by measuring the volume if there is a difference of say 1 cc, then what are you going to do if the engine is otherwise running well? Is 1 cc of volume in a street engine which is less than 2% of combustion chamber volume going to make any noticeable difference? I think not. It would be a lot of work for the average owner to go to such lengths for a street engine. Seems kind of anal to me to pursue such perfection.

David, I stand properly accused.
There are thousands of engines which run just (sort of) fine absent that sort of (anal) attention.
Of the 10 or 15 I've built, none of the first of them were 'wonderful', but each build became an education in how the next one *should* be built.
No doubt few desire to devote that sort of (anal) attention to the effort; that is simply a matter of choice. If, however, you really do want to craft a *superior* engine, there are ways to do so, and there's no harm in offering the ways to do so.

[C J Murray]

At the ECH in Ocean City NJ I will be giving a little talk about engine building and will be concentrating on the way to choose specifications to get the desired result for the way you intend to use the car. I will also try to explain how to measure and analyze some of the clearance issues that should be checked during a build. Please attend if you have an interest in the subject.

[Ron LaDow]

At the ECH in Ocean City NJ I will be giving a little talk about engine building and will be concentrating on the way to choose specifications to get the desired result for the way you intend to use the car. I will also try to explain how to measure and analyze some of the clearance issues that should be checked during a build. Please attend if you have an interest in the subject.

How about a vid or a write-up for those of us a bit distant?

[Wes Bender]

Sounds like an excellent article or series of articles for the Registry magazine. Gordon and CJ??

For the record, I'm with Ron on the careful matching of volumes. If the person is rebuilding his own engine, one of the benefits is that you aren't under any pressure to get it done in as few man hours as you can (as a shop might be). You can take your time and get it right. Matching volumes comes under that category. And, David, while it might be difficult to measure exactly how much difference it makes, it will certainly feel like it does to the guy who rebuilt it and drives it.

[Jacques Lefriant]

Hi
does anyone have any statistics from the days that the factory did the engines of how many did not meet the desired output and had to be redone?? Also has anyone seen extra cylinder base shims used to compensate for the heads that had unusually low volumes from the factory?
j

[David Jones]

Wes, I agree it is nice to have matching chamber volumes but my point was in asking how close does it need to be in reality for a street car. I would spend hours on race heads swapping valves and recutting seats to get down to but not below the 43cc minimum head volume specified in the rules, but on the dyno I found no discernible difference between head volumes of 42 to 44 cc when it came to performance because I did take those heads and reworked them to get the volumes exact and then did another dyno run and found that I had gained nothing. Even so my engines would get upwards of 6K rpm using the puny single 28mm carb and the highly restrictive manifold. All the horsepower was to be found in the porting and balancing of components plus piston rings that cost more than a set of P&C's. In F Vee the carbs and a good manifold were costing over $1500 when I quit. Just think, a 1200cc engine was over $8K to be competitive in national races.
As a by the way comment I would also add that all those years building F Vee engines taught me a lot regarding 356 engines contrary to what Harry Pellow used to say about VW mechanics.