New Project: 350 to 455

[garyesbuick]

Hello All
I’ve made the decision to swap my 350 engine with a 455. I don’t have a GS so I will not feel guilty about modifying this classic. I have all winter to get it done as I’m not heading south this winter, due to health issues. I hope to get lots of advice from “The Group” and make it a fun project. The general plane is to find a 455 running engine and install it into my car without having to rebuild it or do any serious modifications to it. I want to drive it next summer and enjoy it as usual. Next winter I can decide what I want to change or add or even modify. I know there will be suspension work that I will want to do as well as making a change to the transmission. I’ve been watching guys with the TH200 R4 tyrannies. They have become more and more popular with the Hot Rod guys for there ability to bolt up to BOP engines as well as the performance parts available for them to beef them up to tolerate 600 hp engines with 550+ ft lbs of torque. Having that 4 speed Trans would be kewl for highway driving. Anyway the objective is to do a little bit at a time and keep the car running for use in the summer.
My first request for some input is regarding the engines. I have found two engines 1) 1970 LeSabre with 67,000 mi. 2) 1972 Buick Rivera with 89,000 mi. I’ve seen and heard both of them running; the LeSabre had a rough idle but it has been sitting for 2 months. The Riv has been and still is in use. Was not able to do a compression test but they both sounded strong. I’m thinking the 70 LeSabre. I believe the engine will have a higher compression than the 1972. Anyone got any thoughts??
Gary

[raycow]

I agree that the 70 is the better choice if both are in equal condition. However that "rough idle" would have me worried if you aren't able to run any tests on it. Does the engine smooth out under load, or does it miss then too?

Ray

[bob k. mando]

the 1970 engine will definitely be higher compression, assuming nobody has been monkeying with the engines.

either one of them should have the full suite of oil mods done ( including the larger dia oil pickup ) at the next rebuild.

[garyesbuick]

Yahoooo!! Picked up the engine yesterday and now have a 1970 455 engine in my garage. Everything looks pretty good so far. I’ll start taking some pictures first and then begin unbolting stuff so I can start cleaning. It doesn't appear to have had any parts taken off, changed or any bolts moved since new, all looks original, probably means I'll be braking bolts. I tried to loosen the altinator and couldn't budge it. I've sprayed it with liquid wrench and will let it sit for a while.

I got some casting numbers
Eng # 1231738
Intake # 1231718
Carb# 7040240-ND 22059 or 69 hard to read
I'm going to pull the valve covers and get the head numbers soon.
I looked for a number on the driver’s side head between the two front spark plugs but couldn’t see anything. I did find a “ SF “ below the back two spark plugs, not sure what that means, I’ll have to check into that. The TH400 transmission is an 9” tail shaft and is still bolted to the engine. I’m hoping to maybe trade it for a THM200-r4 trans. I don’t want to cut my driveshaft for the 400.
Anyway, I'm happy about getting the 1970 engine, even though the tranny is too long but I got it at the right price; no charge for transmission, so I can't complain.

Gary

[carmantx]

Congratulations. Now the fun begins.
That is the correct original Quadrajet for the 70 455. It is 750cfm.
You will have to make some changes to drop in the 455 in case you are not aware.
motor mounts, frame mounts
fan shroud, ( a big car shroud will work, I used one from a LaSabre before)

It is absolutely worth it as far as I am concerned. I just can't keep my 455's stock.....

Here is a link that might help you.

http://www.buickperformanceclub.com/conversi.htm

[raycow]

The TH400 transmission is an 9” tail shaft and is still bolted to the engine. I’m hoping to maybe trade it for a THM200-r4 trans. I don’t want to cut my driveshaft for the 400.
Anyway, I'm happy about getting the 1970 engine, even though the tranny is too long but I got it at the right price; no charge for transmission, so I can't complain.

I agree completely about not cutting up your stock driveshaft, but don't be too quick to get rid of that long shaft TH400. Just measure the approximate length of shaft required and then head for your friendly local salvage yard. Bring back a TH400 shaft that is at least as long as you measured and didn't come out of a Chevy (because of different U-joints). Bolt up the long transmission so you can measure the exact shaft length needed and then have a driveshaft shop shorten the salvage yard shaft.

Ray

[garyesbuick]

I was trying to get some stats on the internet and found this info and would like to know if this stuff is fact or fiction??
I was under the impression that "SS" engin code was the most HP (360hp) buick produced. The other issue I have is the statement that Buick heads do not require hardened valve seats to be installed


interesting stats:
* From Wikipedia
1970Buick. Added to the lineup was a new LeSabre 455 line which shared interior and exterior trimmings with the LeSabre Custom and was powered by Buick's new 455 cubic-inch V8 with four-barrel carburetor, 10.25 to 1 compression and 370 horsepower, which also required premium fuel.

* Ultimate American V-8 Engine Data Book: 2nd Edition Listed in the Engine Identification Codes;

1970 Buick
SR 455-cid 350-hp
SS 455-cid 360-hp
SF 455-cid 370-hp
Not sure where this info came from I read it in “Weights and Measures”

The iron used to cast Buick engines has a high nickel content. This makes the cast iron very strong. Because of this, Buick heads do not require hardened valve seats to be installed in order to run unleaded fuel. Chevy's are bigger and heavier than comparable CID Buick engines because they used very little nickel in the cast iron. Nickel is an expensive strengthening agent for cast iron, which accounts, in part, for the added cost to buy a Buick in the old days. Low quality iron requires mass in order to make it stronger, which is why you will see the physical weight and size difference. I hope you don't think that 4 bolt mains were put in Chevy engines so that they would be "Ultra-Strong" for the performance enthusiast. This is simply not true! They are there because the iron requires strength to keep the cap in place - 2 bolts in mush is not as good as 4 bolts in mush.

Is this all been discused before and I just havn't found the form??

Gary

[Dr. Frankenbuick]

Gary,

The SR and SF engines were reported to have camshafts with different lifts accounting for the difference in HP (350 and 370 HP). In reality, some have found that they share the same camshafts. The SS had a larger cam lift and had larger Stage 1 valves, but it was underrated at 360 hp. The HP ratings were more of a shell game for insurance companies then actual comparison numbers. What is important for you to know is that the Stage 1 valves and a good camshaft will make a real performance difference in this engine. That is what should be carried forward.

There is higher nickel content in our valve seats and they have been work hardened over time. I have had many 300, 340 401, 425 and 455 engines with no valve sinkage over time and usage with unleaded fuel. Additionally, there have been several GS-X-Tra articles supporting the same contention in the past 25 years I have been a member. Over the same time period, there have been no articles cautioning against unleaded fuel with stock valve seats in our engines.

[garyesbuick]

I’ve done most of the clean up and I’ve got the power steering pump, alternator. and fuel pump off. Lost the alternator bracket as it had a small crack in it. I don’t know why one would mix aluminum with steel. I already know my bracket on the 350 engine is also broke so I’ll be on the hunt for a new one…..
I have a couple of questions, 1) I know that I have to change the motor frame mounts location, do I have to change the location of the mounts on the engine. I plan on replacing them with new ones but I’m wondering about the placement location.
2) Is there some oil pressure modification that I should do while the engine is out of the car without taking the engine apart? I will be taking the oil pan off so maybe I could change the pick up if that makes any difference. I was also thinking about installing an oil pump booster kit.
Any input would be appreciated
Thanks Gary

[bob k. mando]

without a full tear down you're really limiting what 'oil mods' are even possible.

pretty much your only options are going to be installing the larger 5/8" dia pickup ( rather than the 1/2" that should be on it ), possibly installing a TA timing cover and, if you feel really froggy, swapping in neoprene seals on the mains for the rope seals.