AMC 360-401 head

[NormS]

I'm helping a friend modify a Farmall model H tractor engine for a pulling tractor.The stock head does not lend itself to making much power, so we are hoping to be able to adapt an automotive head with the same cylinder spacing. The cylinder spacing is 4.750", which is the same as an AMC 360-401 and the Buick 400-455. We'd like to mock up an AMC head to see if the bolt holes and pushrod holes will work on the model H block. The bored model H four cylinder block will have cylinder bores around 4.250"-4.310", and will be around 350 CI , depending on the stroke we choose.
Does anyone know where we could find an AMC 360-390-401 head? It doesn't have to be a working head, just one with the head bolt holes, pushrod holes, valve guides, and chambers intact. Thanks, Norm

[Vintrcr]

This link should get you to an AMC head blueprint. It’s a start, good luck.

http://www.bulltear.com/forums/showthre ... d7e8d4d6e7

[Ken_Parkman]

Sounds like and awesome project. I'll gladly donate a head, but I'm near Toronto, wrong side of the border for convenience. Where in Michigan are you? There is a fairly significant base of AMC performance knowledge west of Detroit.

Are you talking iron or aftermarket aluminum, and what kind of rpm/power are you talking?

A suggestion is to pick up a cheap Fel-Pro head gasket to start. It does not have pushrod holes, but will get you started. AMC lifter bore spacing is 1.94". Do you have a picture to show of the H?

Trivia, but International used the AMC 401. It was called the V400; available in travelalls and maybe pickups? You could even say it was "factory" equipment.

[NormS]

Ken, I'm about 1 1/2 hrs north of Detroit. Do you know who I could talk to in the Detroit area? Being that this engine will most likely have a 4.310" bore and 6" stroke, it won't be revving much past 2800. These vintage tractor pulling engines are all built for low rpm torque. The trend is to bore and stroke them as far as they can go, and then the original heads and manifolds can't keep up, even modified as far as they can be.
If we find that an automotive head can be modified to work, then we may get an Edelbrock aluminum head. We want to keep the intake port volume fairly small, to work with the low rpm where the engine will be run. and with the power level. With a modified original head, one of these is lucky to make 200 hp.

Vintrcr, Is there a better copy of that drawing somewhere? When this one is copied out, the dimensions are not readable.

Thanks guys, Norm

[PackardV8]

Don't overlook the Mopar B-series heads as a possibility. The bore spacing is close enough to your IH that it could work and aluminum heads for them are more readily available than Buick or AMC.

Comes to that, why not go with the B-series Mopar hemi head? Now, with a billet TF head, you could put the bolt holes where you want them. Run it on E85 and that would be a real corn binder.

[Vintrcr]

Norm,
I’ll check my archives tonight for a clearer head drawing. I might have a good block drawing which will get you some of the desired dimensions.

[Walter R. Malik]

Don't overlook the Mopar B-series heads as a possibility. The bore spacing is close enough to your IH that it could work and aluminum heads for them are more readily available than Buick or AMC.

Comes to that, why not go with the B-series Mopar hemi head? Now, with a billet TF head, you could put the bolt holes where you want them. Run it on E85 and that would be a real corn binder.

"B" series Mopar heads have a 5 bolt pattern "hold down" which is not very adaptable to a 4 bolt pattern like the AMC or Buick; Edelbrock offers both.

[PackardV8]

But since it's going on an IH, the four-hole heads might be worse than the five-hole Mopar. WTFKs? If this is, in fact, the gasket, it may only have three, so five might fit better than four, or not.



IIRC, the binder had maybe 6:1 compression, so three might have been enough.

[NormS]

With these vintage pulling tractors, the torque of the engine at the reduced rpm's near the end of the pull is actually more important than at the higher rpm's earlier in the run. For that reason, I think it would be easy to get the port velocity too low at those lower rpm's with too big a port.
The 185cc intake port of the Edelbrock AMC head appears to be about the right compromise on port volume and port flow. It's all a balancing act, trying to find that best compromise. I feel the best situation would be a small volume intake port with as much flow as could be obtained... a"very active port", to use a term some engine builders use.
On some of these modified tractor engines, the trend is to hog out the head ports as big as they can go, and those engines a typically "dead" at the end of a pull because the port velocity drops too low. I'm trying to stay away from that scenario.
Being that this tractor will be running where the rules are pretty much "run what ya brung", I would prefer a small screw blower and methanol.

Norm

[PackardV8]

What are the winners running? Seems a turbo would be a natural.

[ProPower engines]

How thick is the deck?? would it stand a plug and redrill to the new pattern??
Or what about adding a deck plate then drilling the new bolt pattern in an aluminum deck spacer Then sleeve the block to suit.We did that with an old mercruiser 485 block and put a BBC head from some old pro stock on it for a tractor pull deal.

It worked well and as long as the rod length to stroke ratio is not screwed up too bad it may be worth a look see .

[mag2555]

The stock AMC Exh ports are atleast 15 cfm better then the Mopar heads ( big block Heads) and the Intakes flow just about the same , so stick with the AMC if its iron heads your running, and with a 2800 rpm peak that's the way you should go unless you have access to a flow bench to reduce the Intake port volume of a aftermarket head!
A 1.94" to 2.05" valve should be all you need and going up to a bigger valve size so that you can convert the head over to a 30 degree intake seat should be part of the plan also.
Next would be trying to keep the Intake port to about 160 to 165 CCs along with porting work to attain 250 cfm@28" at no more then .500" lift.

[rebelrouser]

Not sure of your budget but Indy cylinder heads makes new aluminum heads for the AMC engine.

http://www.indyheads.com/images/price.2015.14.pdf

The stock 401 heads had a 30 degree seat on the intake which lends itself to better flow at low RPM's Last year I did a 401 amc for a guy who mud raced and had to have an AMC engine in the jeep for his class. I put 440 chry intake valves in it and ground the seats to 45 degrees, the flow picked up, did not dyno the engine, but it was successful in the class.

[NormS]

Those Indy cylinder heads are nice, but the intake port volume is way too big for the Rpm and power range of this engine.

[randy331]

a 30 degree seat on the intake which lends itself to better flow at low RPM's

Doesn't ST have a comedy section for this type of stuff ?

Randy