This is not a question for my truck, but I am hoping to beg your pardon due to the knowledge base available on this small block forum. Due to illness in the family this project has stretched out until now, but I should now be picking up on it again.

I am throwing together an interim motor with some available pieces that I have on hand. I expect to cruise in my 64 Galaxie this coming Summer with the proposed engine while I build my stroker motor.

What I have is a decent condition 289 short block with a stock cam all in good shape. I have a set of warmed over 69CC heads that I bought for the stroker motor. These have 1.95 intake and 1.6 exhaust (Chevy valves.) I have cleaned up the bowls, and worked over the exhaust ports and match ported them.

These open chamber heads on the flat top pistoned 289 should yield about 8.1 or so compression. Since I have little experience with low compression combinations, I am wondering if any of you have experience with such low compression in this short stroke motor. Would this engine be really sluggish or would it have a little snap? I will be driving it below 3,000 or 3,500 RPM.

Any sharing of experience is very much appreciated.

 

I had a stock 9.5 2bbl 289 that would rev to 5000 rpm with a bigger 2bbl off a 390.

If you dial the carb in properly, it will be a little soft but will run and pull from just off idle, and start to wake up big time about 3000. It should cruise easily at 2500. Expect 180 hp or so, with maybe 230-250 lb/ft from 2500 or so, and sign off at 4500.

Ymmv, good luck with it.

 

Yes, I have a 289 in the car now much as you describe. With 9.5 CR, although it knocks, is snappy and pulls the car along okay. My concern is about having basically the same engine with only a little over 8:1 CR. I have had other engines with such low compression that seemed soggy.

Thanks for the response. Has anyone else dealt with one of these engines in low compression form?

 

Yes it will be soggy compared to what you have now, it would make a perfect candidate for forced induction though.

 

Yes I have a knocking 9.5:1 engine much as you describe in the car right now and it propels it along quite well. My concern is that when I lower the CR to 8:1 how soggy will it get?

 

Thanks for the response Ski. I'm having computer trouble, so that's why the double clutch post. You slipped in between the post that I thought didn't go through and my second attempt at the same post.

Your responses are always appreciated.

 

Follow up! Well the excitement of finishing an engine project makes me want to tell someone about it so here goes:

As I indicated in the first post during the holidays, I was piecing together an engine from junk and pieces on hand. I got a previously rebuilt engine out of a parts car that I bought. Everything in the engine mic'd out good, so that made for a good platform for a low buck interim engine. It will let me cruise the car this summer with the goal of building a stroker motor to put in next fall or Winter.

This post discouraged me from building a low CR engine from pieces on hand. I ended up getting a very nice set of early 289 heads with big valves, pocket porting, screw in studs and guideplates. The downside was that they had long stem, rail rocker type valves but I got them for about the same money as a new set of valves would have cost for the heads off the scrap motor. The valves in the old heads were scary thin from previous rebuilds.

I bought gaskets, rings, bearings and odds and ends along with the heads, so that is the only cash outlay of the project. I reused the cam, roller rockers and timing set that were nearly new from my junker motor. The cam is a Comp 252H, not much, but makes for a nice running stocker and works well with the compression of about 9:1 that I ended up with.

Time for this project has been very limited for the last year or so due to my Dad's failing health and having to take care of him. He passed away in January, so getting back on the project has been therapy. My shop is a tin building with no insulation and the rainy, cool Winter has kept me out of there for a lot of the Winter. It seems like every weekend has been just uncomfortable enough to keep me out. This past weekend was great, so I pretty much finished it up.

The engine came together well and started right up for cam break in. There was a noise from one of the rocker covers upon start up. I shut down and pulled the valve cover. The tall valves which required longer pushrods, moved the rockers up close enough to tap on the cover at the baffles. I "clearanced" the baffles and raised the covers with double gaskets and it was able to run through cam break in.

I then ajdusted the carb, set timing and a little of this and that. The result is a very nice running engine that grabs revs quick and seems like it will run strong. Thanks to the replies in this post, I didn't build the low CR engine which would probably not grab revs like this one does. The remaining problem is a noise that occurs when blipping the throttle up to about 2 grand, and releasing it. I THINK that this is from rocker arm/valve cover contact. I will work further through this starting tonight. If I have to I will go to stock rockers and valve covers.

So for an outlay of about $350 plus the use of stuff on hand, assuming I solve my noise problem, I have a nice running 289.

The car is a fastback Galaxie 500 that I have converted to three on the tree and manual steering and have gotten everything in top notch mechanical condition. I used the rear gear, a 3.50, from the three on the tree parts car. Back in the day, we drove these low geared three on the tree cars down the highway and thought nothing about it. In todays world of overdrives, this car in third gear at highway speed makes you SERIOUSLY want to shift to a higher gear which of course does not exist. No matter, it's only a toy, so I'll use the gearing that Henry thought that it needed.

I hope to lick the noise and get the hood back on tonight or in the next few days and I can't wait to see how it goes down the road.

Thanks for listening and thanks for steering me away from a low CR engine.

 

Follow UP............

At the time of the last post I still had a noise in my fresh motor. It turned out to be a parts mismatch. I used the spacer from the early timing gear on a later timing gear and pushed the cam too far back. Live and learn.

It scattered metal through the fresh motor, but I put in the original cam from that motor and I had the lifters in a box so that I knew exactly which lifter bore they came from, so they went back in their orignal positions on the block they came out of.

A magnetic drain plug and several overnight oil drains got the metal out of the motor. The motor was running REALLY good, so I added an air conditioner to the car and got it sorted out well.

My wife and I went to lots of different car shows in our end of the state in the car this year. We drove 500 miles or so on the July 4th weekend in air conditioned comfort with total reliability. We enjoyed travelling in the car this year and it helped me to get over the loss of my Dad.

Now that it's Winter I hope to do some cosmetic improvement on the car.

I didn't get the stroker motor that I wanted, but the car served it's purpose very well.

Thanks to all who participated in my posts while thinking through the motor I wanted to build and the one I ended up with. Maybe after the cosmetic improvements I'll get back to building the stroker motor I wanted.