Got questions?
We’ve got the answers—the Summit Racing tech department tackles your automotive-related conundrums. This week, we help a reader overhaul his Rat motor for street/strip performance.
G.T. • Keaau, HI
Q: I have 1973 454 big block Chevy. It has 8.5:1 compression, stock oval port cylinder heads, a Crane PowerMax camshaft, an Edelbrock Performer intake, and a Holley 750 cfm carburetor. The engine needs an overhaul but I would like to retain the stock cylinder heads and intake. What would I need to increase the compression ratio? Also, I enjoy the sound of an aggressive cam—what do you recommend? I want it to be a stout street engine but yet have some fun on the track!
A: For starters, rejuvenate your engine with a Sealed Power premium engine rebuild kit (FEM-CSMHP767). It includes everything you need for an extensive overhaul without breaking your budget, plus you can retain your stock cylinder heads and intake. Once you’ve installed the kit, your compression should increase to around 9.8:1. Keep in mind that these kits are custom ordered by your bore diameter and bearing sizes—talk to a sales expert to make sure you’re getting the proper kit for your application.
As for your camshaft, we recommend a COMP Cams® Xtreme Energy cam and lifter kit (CCA-K11-250-3). It includes a hydraulic flat tappet cam that builds big power from 2,300-6,500 rpm and has 240-degree intake/246-degree exhaust duration @ .050-inch lift. Also included are a set of lifters, a timing chain and gears, valve springs, seals, and locks, retainers, and assembly lube. The aggressive lope of the Xtreme Energy cam will be music to your ears!
thanks guys… at 6 yeas old I’m finall going to get t drag race.. my dedicatio to family and country came first in my lfe but now its my turn… I just hopei have enough time left to accomplish my dreams.. with yor soggestions and parts I hopeit will be son. thank you,,,,
Hello mat,
I had left a ? had not received an answer. I have a 427 BBC It was professionally rebuilt ten yrs ago and never fired. It has been sitting in our shop. What do you suggest we do prior to initial start up?
Hi Rich. I ran your question by the top minds in Summit Racing’s tech department (they’re smart), and the quick answer is that it depends on how the motor has been stored for the past decade. I have to ask you to take one more step. It will be worth it. Please call Summit Racing’s tech department at 330-630-0240 and ask them the same question you asked us. They’ll ask you about the motor’s storage conditions, and then be able to give you the best-possible advice on your start up.
You’re quite welcome, Mr. Powell. Thank you for your service. Good luck building that car!
I do have a 289 engine on a 1966 Mustang .. Its runs at 220 temp when stopped ,but on opoen road runs bellow 175 ,, my son a madern auto technitian ,sats its too hot ,, I an ald school ,says not ,, who yuo think is wraight????