8ba 275 carb options

[Alberta50fordor]

Originally Posted by tubman

There are 3 to 4 bolt adapters available, but the problem is the throttle bore size. I've never tried to bore a 3 bolt manifold, but I believe "Ol' Ron" on here has, and I believe that when you go to the full 1 7/16", it breaks through into the carb heat chamber. I think they got by that by boring it oversize and using thin sleeves.

EDIT : Here's a picture of a 3 to 4 adapter I got from Speedway Motors. I added a divide plate and it ran better than without it.

Would you recommend the adapter route? These are the carbs that came with our 55 bel air and 265 (in pieces)

[Alberta50fordor]

Also, a guy that I’ve been talking to in calgary that builds flatheads, race and street engines has an isky 3/4 max 1 that he recommends, what’re your guy’s thoughts on this cam in this engine vs the ford eab cam?

[Alberta50fordor]

I also have Sanderson headers in the car now with 2” all the way back with glass packs, not that these engines can move much air but I got a good deal on them so that’s what I’ve got

[28fordroadster]

I was going to ask about those 3 bolt to 4 bolt adapters, Thanks for bringing them up in this thread. Tubman and ol ron you guys know your stuff. What a great thread! I have scrounged a 4 bolt merc intake and a bubba's chevy distributor. I can't wait to try them.
Gramps... what's happening with that perfect engine build thread?

[Ol' Ron]

I don't use an adapter. Just fill theOS vacuun port with JB weld and drill the third hole. Alittle filing to the front holes will drop right on. Most problems can be solved with money, but thinking is much cheaper when you don't have any!!

[tubman]

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Originally Posted by Ol' Ron

I don't use an adapter. Just fill theOS vacuun port with JB weld and drill the third hole. Alittle filing to the front holes will drop right on. Most problems can be solved with money, but thinking is much cheaper when you don't have any!!

So you end up using just three bolts to mount the 2G. Good thinking. I never would have thought of doing that. I started collecting Merc manifolds as soon as I found out that a 2G (small base) fit perfectly.

[Ol' Ron]

Yes the merc intake is a better option , as it can be bored to the right size. Unfortunately, not everybody is that luckily.
G

[Alberta50fordor]

Originally Posted by Alberta50fordor

Also, a guy that I’ve been talking to in calgary that builds flatheads, race and street engines has an isky 3/4 max 1 that he recommends, what’re your guy’s thoughts on this cam in this engine vs the ford eab cam?

Reading a previous post about that cam it’s good for stock displacement engines, how would it do in a 272?

[Alberta50fordor]

Are these 8cm heads any different than the 8ba heads?

[tubman]

Yep. larger chambers. For some reason, Ford Motor Company decided to keep the compression ratio the same for Fords and Mercury's (which have larger a cylinder volume because of the longer stroke), so they made the chambers larger to keep the C/R equal. They are more like an 8RT head.

[Alberta50fordor]

Originally Posted by tubman

Yep. larger chambers. For some reason, Ford Motor Company decided to keep the compression ratio the same for Fords and Mercury's (which have larger a cylinder volume because of the longer stroke), so they made the chambers larger to keep the C/R equal. They are more like an 8RT head.

So a good combo is the merc stroke with ford heads?

[flatford8]

Yes EAB Ford heads……but you still need to check the amount of “squish”….Mark

[Ken Henry]

The Max-1 will make more power sacrificing low rpm torque. The book Flathead facts has nice dyno results. I think it is worth it… There is more lift so valve clearance needs checking.

[tubman]

This is a always a good reference : https://www.tildentechnologies.com/C...rformance.html. It shows a stock 8BA cam to have a lift of .307", an Isky MAX-1 to have .350", and an 8CM comes in at .337" (unfortunately, there are no specs for EAB, although I would expect it to be similar to the 8CM). Thus you can see that an 8CM (and probably an EAB) are a significant upgrade over the stock 8BA cam, approaching the MAX-1 in lift. When I did the Merc in my '51 club coupe, I had a new MAX-1 cam and kit I was going to use, but after some thought and discussions here and on the H.A.M.B., I decided to keep the 8CM. The way the car performs, I think it was the right decision.

I used the MAX-1 in a 258" engine for the "T" tub I am building. I figured it was better in an 1800 lb car than one the weighs in at a hefty 3200.

[Alberta50fordor]

Originally Posted by tubman

This is a always a good reference : https://www.tildentechnologies.com/C...rformance.html. It shows a stock 8BA cam to have a lift of .307", an Isky MAX-1 to have .350", and an 8CM comes in at .337" (unfortunately, there are no specs for EAB, although I would expect it to be similar to the 8CM). Thus you can see that an 8CM (and probably an EAB) are a significant upgrade over the stock 8BA cam, approaching the MAX-1 in lift. When I did the Merc in my '51 club coupe, I had a new MAX-1 cam and kit I was going to use, but after some thought and discussions here and on the H.A.M.B., I decided to keep the 8CM. The way the car performs, I think it was the right decision.

I used the MAX-1 in a 258" engine for the "T" tub I am building. I figured it was better in an 1800 lb car than one the weighs in at a hefty 3200.

Found a post on the H.A.M.B about the eab cam, .328 supposedly so if that’s true it’s not far off from the 8cm
https://www.jalopyjournal.com/forum/...ab-cam.398204/

[Ol' Ron]

Anyone rebuilding a flathead should get a copy of JWL's book. This can save you a great deal of mone and get a better engine for the money you do spend. Max VP has them. And you;ll help his widow.
Gramps

[miniceptor86]

Excuse my ignorance. What is JWL’s book?

[miniceptor86]

Oh and I guess I’m one of the lucky ones. I scored this Merc manifold, bored it out with a drill press and hole saw followed up with a sanding drum in a hand drill.

https://www.fordbarn.com/forum/pictu...ictureid=45339

[Ken Henry]

Flathead Facts. Excellent reading

[miniceptor86]

Thanks.