Trying to get Power out of a 225

[Darter6]

Good read.

 

[Trevor B]

I expect to have about a shade over 200HP out of my slant. The block has been bored 30 over, decked 90 thou head cut 10 thou, 1.70/1.44 oversize valves 340 valvesprings installed, mild port and polish on the head, pretty stout cam. All the measurements indicate close to a 10 to1 CR and about a 8.05 Dynamic CR. Will be running Clifford long tube headers and an Offy 4 barrel intake with a FiTech unit. It ought to go pretty good in my early A wagon with a 4 speed and 3.23 gears.

Last slant that I built was in a 65 barracuda. It turned in a best e.t. of 14.7s. I do not have the time slips, so I do not recall the weight of the car. However, it should have been a 180-190hp slant.

Basics of the build:

.030 over
1.77/1.44 valves, basic resurfacing of head
.100 off the block
Factory super six intake w/adapter for a 350cfm holley 2bbl
Cheap chinese crap exhaust manifold attached to 2.25 full exhaust
do no recall the cam specifics, but it idled smooth as silk
904 stock transmission
4.10 rear when it ran the 14.7, mid 15s with 3.55s

Drove it all over San Antonio when it had the 3.55s. Lots of fun on the road. People always thought it was V8. I never told otherwise. Really wish I still had the car. I, no doubt, left a lot on the table power-wise, but it was a great daily driver.

You really need to check out slantsix.org if you haven't found it yet.

sb

Sorry to jump in and hijack but this is of interest to me:
65 Dartman and mopar_nocar: did either of you install new hardened exhaust valve seats when you put in the 1.44 exhaust valves? If so, was there any danger of running into the water jacket on the larger seats?

 

[65 Dartman]

@Trevor B I make it a practice of having hardened exhaust seats installed in ANY head I send for reconditioning. My machinist had no problem installing hardened exhaust seats in both my slant 6 heads (as well as a set of 70 340 heads and a set of Gen I 58 392 Hemi heads)

 

[Trevor B]

Thanks - so did your machinist install new seats and then hog out to fit the larger valves? and if he did put in new ones, were the seats themselves oversized?

 

[65 Dartman]

@Trevor B I do not know the exact procedure he used in installing the seats as I was not there during the procedure. I do know he measured the exhaust valve in order to order the correct size seats. Sorry about the lack of help - I would talk to your machinist for his exact procedure. I have used mine for a number of years so am comfortable with him and his work.