cost of head rebuild vs. crossflow head + rebuild

[barroom hero]

curious as to what the cost difference is between a crossflow head, and just a stock head rebuild. if the difference isnt too much more, would you suggest going with the crossflow head on a US 200? just trying to decide what to do.

 

[Anonymous]

Hi BR,

First, the cross flow conversion requires a complete tear down. That is the engine must be disasembled to the bear block. Much more expensive than head work alone.

Second issue, while the cross flow conversion looks good at this point, it isn't proven yet. I prefer to let Jack continue the process and work out any issue that are yet to develop.

Steve

 

[xctasy]

For the alloy head, if you want to use the stock 2-bbl intake manifold
or aftermarket 2-bbl Cain,Lynx, Ultraflow,Redline or
4-bbl Cain,Lynx,Redline

you will have to use :-

a) one 8.125" jackshaft extension so the distrubtor clears the intake manifold. It is a machined component I'm using on my 200 Cross-flow.

b) one 1.5" manifold spacer to clear the distrubutor (cast alloy or phenolic).

Jacks is really on to it with the block modifcations. I cant speak highly enough of the work hes gone through.

Just remember, a 2v conversion will always be more cost effective since there is no need for a block teardown, as Steve says. This is even the case if an alloy head may go for 250 bucks landed in the US, verses 750 for a 2V. The alloy head saving is nothing if your committed to a block rebuild, then your on Gods good humour as to how much your going to have to sink into it.

It's very important to be totally realistic before setting forth on a course that hasn't been proven yet. I'm totally enthusiastic about any developments for these wild little engines, but you should look at the 2v option first.

The race is on. I've been flat-out designing components and can't wait to get my 200 Cross-flow done. I've shelved my 228 cube block for now because of a mainseal issue.

I think the x-flow will be lighter and faster in my Cortina project car. But its going to set me back big dough to get it running with all my project bits, here in Kiwi land where you can get whole alloy head Falcons for the price of a used Playstation 1.

 

[Anonymous]

well if that is so X I`ll sell you my old ps1 for $10.oo and free shipping so how about that head ?

 

[xctasy]

The tyrany of distance...

 

[xctasy]

I think I've got it. Joke! (Good one!)

With all seriousness, I'd never send you anything unless you were going to be guarenteed to get it.

Especially if there are others who are much closer who can get you one reconditioned. My last K-lined and reworked head cost me 700 dollars NZ including the head gasket. The core head was only 35 bucks NZ.

No use getting a 35 dollar head that needs rebuilt, and then needs a new deck modification to the block, a distrubtor mod and a special cam.

Talk to Aushead or AzCoupe. I'm not into trading unless I've got a container and some means of ensuring it gets there.

 

[Anonymous]

it was just a joke X I don`t have the skills or tools or the money for the tools to do it (being my age sucks I still don`t have a job or a way to get to it :roll: ) .

X are stock 305 chevy pistons stronger than the stock 200/250 ford pistons by any chance ?

 

[xctasy]

I believe the stock 305 pistons are on par with the 250. The peak rpm on a 305 is greater than a 250. The compression trough is bigger on a 305, and they are designed to run similar hp per cylinders.

I think a healty 305 had about 140 hp net, maybee 180 if it was TBI. Thats about 18 to 22 hp per hole. A 250 has about 100 hp net, or 17 hp per hole, even though it was claimed to have about 155 hp gross.

So stress-wise, the options are in favor of the 305 piston. I'm not aware of any 305s having 'handed' pistons, so as long as the crank , wrist pins, and con rod clear the slipper skirts and you can go for 56 thou oversize, you have a candidate. Just don't tell everyone you have Chevy pistons.

Oh, I was wrong on the need for a distrubtor extension seeing as you have a 250. A US 250 will take an alloy head with Jacks mods. You don't need a new distributor, it just gets pretty close to the intake manifold, and will prevent removal of the distributor cap unless you remove the intake.

 

[xctasy]

Just some notes for your info. I hope this will help show the changes from the Aussie 250 x-flow had over a US 200.

1. This is the alloy and cast iron X-flow heads. Good samples for rebuild are easy to find.


2.The alloy head is below. Notice the windowed sections. The iron one is filled in over the inlet ports with an ultra heavy casting. This head would have less issues with distortion on a 200 block, but its a small bag of cement heavier. The alloy head intake doesn't fit it as the manifold on the cast iron head is taped off the second cylinders intake branch. This is the alloy head with 2-bbl carb. Cast iron cross flows were 51 pounds heavier, and came with a 1-bbl Bendix carb. As you can possibly imagine, any distributor has to clear the cast iron or alloy head intake manifold. Best option is to extend it through intake port 1 and 2, by adding an alloy spacer to push the manifold out and make a clear way space. Then add between 8.125 to 8.742" inches of length to the distributor mount.

3.The alloy head looking from the drivers side (US-speak!). The extra 1/2" Jack adds to his 200 US block is to duplicate this. The back of the cross-flow is the same as the 200 US engine, but it starts getting wider here. This is important as it provides support and sealing to the head, as the splayed pushrods cut outboard of the 200 US block by about 1/4 of an inch. In fact, both sides of the block are extended from 200 geometry. It is about 7 inches wide, up from a meare 5.625" on the 200 US engine. The water gallery was swaped from the true left in the 200, to the true right in the 250 x-flow shown here. The alloy head had these round location tangs to stop head to block fretting. (Alloy expands more than cast iron).

 

[addo]

I gues you've got to take the dig camera back tomorrow, but a suggestion to help convey the "less than simple" aspect of the swap...

Lay a non-crossflow head gasket on the underside of the crossflow head. Sometimes, also you will find a non-flash image comes out better after lightening; it has more depth than a flash pic.

 

[xctasy]

Cool mate. 8) Like every thing I do, it was taken in August, yonks before I knew about it. I often hook into something without asking to get familar, and then sit on it for an age. I hoped to post this on my Paradise acount last September!

I have looked at all my photos, and thought, geez, if I only spent a few more moments. Next ones will be grovey.

I'm still working on some better pictures for my distributor, bellhousing and the log-head EFI and what not. Pixel images, even on greyscale, look bleedin' awfull. My 9 year old does better drawings on Paint than I do scanning my pencil plots.