Compression numbers on stock engine

[38plymouth]

I checked my compression after I put on a Fenton head, I'm not at 110-120 pounds. I never even thought to check it with the stock head. I looked in my shop manual and it doesn't tell. I'm curious how much it changed. Does anyone know what a stock engine in good condition would show?

[Plymouthy Adams]

more important at this moment is if all 6 are equal or at least a few pounds of each other...

[1just4don]

I was checking on that long distance motor buy I was considering. First the owner did a compression check with his gauge he had. checked 88-105 #s. A buddy of his said a good motor like that should be 120-150 compression. He tried it again and found 120-140# across the board with a GOOD compression tester, known to be right Moral of the story--either check your gauge against a better known accurate gauge OR try another and see IF you get same readings??? Might be a long pull job and expensive repairs to find out it was GOOD and FINE to start with. Not all gauges are created equal and time has a way of sorting the cheap from the 'good' ones

[38plymouth]

My numbers were all extremely close when I checked it, they were within a few numbers either side of 115. I do think I did it wrong though, isn't the throttle supposed to be open? I checked it just cranking the engine without touching the throttle. There's a big difference in the combustion chamber from the stock head to the Fenton head, I'm just curious how much it jumped and I wished I thought to check it stock.

[Plymouthy Adams]

Oh no the dreaded compression debate on closed throttle/WOT..think it has been pretty much found that it is basically irrelevant on these engines...both yield same reading per past examples...however ..WOT is the prescribed method...

If you were within a couple pounds of the 115 either side...run that puppy.,...

[38plymouth]

Believe me I'm ready to run it, I just can't. I'm waiting for the shop to call me to tell me when to bring it in for the custom exhaust pipes. I was praying it would be tomorrow so I could drive it this weekend. I'm ready to drive it with the open exhaust manifold, it's LOUD though. My wife keeps asking me why I keep starting it and revving it in the garage, she thinks I'm playing, I told her that I'm still tuning the carb.

[greg g]

A stock engine in good condition should be between 110/120. So 115 sounds pretty good especially if this is a cold dry motor. I for onw will put a vote in that closed throttle or open throttle will not make a noticable difference. Just noticed you say you are located int he finger lakes. Where abouts? I am out side Syracuse. I get to Auburn a couple time a year for shows and the one at Moravia in September is a nice event. Is your car on the road or a work in progress?

[david lazarus]

Hi 38 Plymouth.

I have a 38 Plymouth bodied Dodge (RH Drive ex Canada). I vote you road test the beast right now with or with out exhaust !!! Don't worry about the neighbours they will talk to you again in few years

Yes please post some pics of this car!!

Rgds

Dave

[Don Coatney]

Wide open throttle is not required as explained here.

[38plymouth]

A stock engine in good condition should be between 110/120. So 115 sounds pretty good especially if this is a cold dry motor. I for onw will put a vote in that closed throttle or open throttle will not make a noticable difference. Just noticed you say you are located int he finger lakes. Where abouts? I am out side Syracuse. I get to Auburn a couple time a year for shows and the one at Moravia in September is a nice event. Is your car on the road or a work in progress?

I live just outside of Seneca Falls. We haven't been bringing the car to many shows or cruises, we have been driving it alot though. I decided to put a split exhaust manifold on the car so I could add dual exhaust, then I lucked into a free fenton aluminum head. I put them both on and now I'm still waiting for the garage to call me to bend up the pipes, it';s been over a week now. I'm starting to look for someone else to do it. It's killing me, I want to drive it again.

[greg g]

let me know if you give some thought ot Moravia. the show is at Fillmore Glen State park. Judged and non judged display. Sunday of Labor Day weekend.

[38plymouth]

let me know if you give some thought ot Moravia. the show is at Fillmore Glen State park. Judged and non judged display. Sunday of Labor Day weekend.

I would love to check it out, but, as it stands now I think I'm going to be at the state fair all day. I'll know for sure by the end of the week.

[38plymouth]

I'm very irritated with the first shop I tried to hire to make up the exhaust pipes. They never called me back to set up the date to do the work, after a week I called them and they wanted me to drive to the shop after hours to talk to the guy that would do it. They were supposed to be the best but I'm sick of chasing them down, the guy was given my cell number and was told to call me. I just stopped at another garage and I know the owner a little bit. He has a pipe bender but I was told he wasn't very good at using it. I might have gotten lucky, he hired a new guy who did all the custom exhaust work for a local street rod shop. I talked to the guy and he really impressed me, I'm dropping the car off in an hour and they are planning to do the work tomorrow. Hopefully this works out.