How much material can you remove in a model a port safely? It looks like a big step in the valve pocket area and around the valve stem. I haven't pulled my engine apart, was swapping manifolds and started checking out the ports.. Thanks John
Didn't remove much from mine at all. I just took a stone to all the 'sharp' edges and smoothed them out. If you allow your finger to trace the flow of the fuel from port mouth to valve you'll feel where the major obstructions to flow are. I smoothed out the area at the bottom of the valve stem and the top of the valve guide (one piece)so that they flow nicely together. This is just for decent street use, you can go further but I'd get a scrap block first to practice on.
A blocks have quite a bit of meat, B blocks do not. I would use 305 GMC V6 valves for exh., just a little bit bigger than stock but would use 1 11/16 for intakes. Get blank valves or cut down Chevy 235 intakes.
hey 4-port Riley are the chevy 235 valves long like the flatheads I was thinking more like a 1 3/4 intake valve with a nice Stipes cam and see how close I can come to a 100 hp all and any input is wellcome Bill
Both are availible in re-grinds and new cores. Re-grings are @ $180 with your core. New cams are @ $350 ea. 4-Port Riley is the man with the plan. I'd do what he said. .
good to know more then one guy make new cams. I could not find a web site. still would love to see some port job pic to go with the bigger valves and the new cam. any one thanks Bill
There's a lot of material that can be removed from an A head. As far as valves, 1 3/4 on the intake and 1 11/16 on the exhuast is as huge as you can get in there. You can make 140hp with those, plus a few other choice parts.
I´d like to see some pictures about porting 4 banger block, if some one have? I haven´t find any good instructions anywhere...
just because im conservative , i would polish & maybe a little contour . but polish the exhaust is alway good . i like to leave the intakes just short of polished for fuel atomizing .. steve
hotrod deluxe march 2009 had a 7 page biuld of Vaughans salt banger by h&h. Shows a nice pic of how big you can go. little to much for the street I would think. The salt gods still won in the end the little banger broke. How you shear the bolts off the flywheel on the salt is a big question to me?????? I dont see any valve seats used on the little race engine. Bill
Yes, the 235 valves are too long and need shortining and re-grooving, no big deal and you can putd the groove where needed to get proper spring pressure. I would flame harden the tips when done.
There was an actual step-by-step porting excercise in "Secrets" a few years back, with pictures (drawings) and flow figures for each step. It was entirely experimental, the guy doing it was experienced but not with A's. B's are lighter up there and ports are not the same shape, so different kettle of fish. They promised a B adventure but never got there. This is in...let me see...the issue that's in the upstairs bathroom. If your bathroom differs, it is the issue with a portrait of Harry Miller on the cover. Will swappit for the issue that shows Ford drawings of upper block areas of A and B...
PS...the porter likes bigger valves...they don't directly help flow, as there are too many other restrictions, but apparently help by simply moving the useable curtain area over closer to the bore!
just wont to keep the tread on the 1st page. I would think more model a bangers would wont to show off there stuff. Bill
Yep, i´m also interest about porting 4 banger. I have already ordered 1,7" intake valves and exhaust is stock. What about other modifications? I have Burns intake for one Stromberg 97 and i´m thinking to go SU1-R camshaft grinding. any comments or proposal? Engine is Model A ´29 in "060 oversize. I´d like to make little more powerful every day engine.
Here's a pic of mine! She runs pretty good but I am having a "learning experience". Here are the details if someone can help. It has started to vibrate worse since adding a higher comp head. Went from stock "C" to super winfield 8.5. Just started it up and ran 30 sec and shut off. Puked water so took off and put on Lion Speed head 7:1. It runs good but vibrates terrible. Balanced crank. Stock babbit. Ordered a new winfield 6:1 and am going to see if the vibration goes away.....opinions?
bcchopit, might talk to max jr at H&H. he's built some good ones. i think they use 1 3/4 intake in some of their good street type motors. I haven't really studied my banger yet. Friend and I are just starting flow work on flathead v8....he's got many national championships in different classes (motors he's built....or parts of) and 30 years flow bench experience. Maybe some of it will cross over. He's taught me a few things to look for already. hope someone posts some good flow info on here for everyone....it seems to be a big secret witht ones in the know including my friend. sorry i can't be of more help at the moment.
just a WAG but did that 8.5 head have a flycut for piston clearance? if no you mite bent a rod or 2....
I think it need to be on the first page I hope to start working on mine this mouth lets see some pic to get me in the mood
Has anybody opened up the intake port inlet to 1 1/2" from the stock 1 3/8" ? I blended the pockets into the port but would like to open the inlet of the port to match my fabricated intake of 1 1/2".. Have 1.7" intake valves to install..
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